Release version 0.3, the last supporting blender 2.4x
[vrm.git] / vrm.py
diff --git a/vrm.py b/vrm.py
index c694b77..86c8fba 100755 (executable)
--- a/vrm.py
+++ b/vrm.py
@@ -1,13 +1,21 @@
 #!BPY
 """
 Name: 'VRM'
-Blender: 241
-Group: 'Export'
-Tooltip: 'Vector Rendering Method Export Script 0.3'
+Blender: 245
+Group: 'Render'
+Tooltip: 'Vector Rendering Method script'
+"""
+
+__author__ = "Antonio Ospite"
+__url__ = ["http://vrm.ao2.it"]
+__version__ = "0.3"
+
+__bpydoc__ = """\
+    Render the scene and save the result in vector format.
 """
 
 # ---------------------------------------------------------------------
-#    Copyright (c) 2006 Antonio Ospite
+#    Copyright (c) 2006, 2007, 2008, 2009, 2012 Antonio Ospite
 #
 #    This program is free software; you can redistribute it and/or modify
 #    it under the terms of the GNU General Public License as published by
@@ -25,793 +33,3091 @@ Tooltip: 'Vector Rendering Method Export Script 0.3'
 #
 # ---------------------------------------------------------------------
 #
-#    NOTE: I do not know who is the original author of 'vrm'.
-#    The present code is almost entirely rewritten from scratch,
-#    but if I have to give credits to anyone, please let me know,
-#    so I can update the copyright.
+# Additional credits:
+#   Thanks to Emilio Aguirre for S2flender from which I took inspirations :)
+#   Thanks to Nikola Radovanovic, the author of the original VRM script,
+#       the code you read here has been rewritten _almost_ entirely
+#       from scratch but Nikola gave me the idea, so I thank him publicly.
 #
 # ---------------------------------------------------------------------
 #
-# Additional credits:
-#   Thanks to Emilio Aguirre for S2flender from which I took inspirations :)
-#   Thanks to Anthony C. D'Agostino for the original backface.py script   
+# Things TODO for a next release:
+#   - Shadeless shader
+#   - FIX the issue with negative scales in object tranformations!
+#   - Use a better depth sorting algorithm
+#   - Review how selections are made (this script uses selection states of
+#     primitives to represent visibility infos)
+#   - Use a data structure other than Mesh to represent the 2D image?
+#     Think to a way to merge (adjacent) polygons that have the same color.
+#     Or a way to use paths for silhouettes and contours.
+#   - Consider SMIL for animation handling instead of ECMA Script? (Firefox do
+#     not support SMIL for animations)
+#   - Switch to the Mesh structure, should be considerably faster
+#     (partially done, but with Mesh we cannot sort faces, yet)
+#   - Implement Edge Styles (silhouettes, contours, etc.) (partially done).
+#   - Implement Shading Styles? (partially done, to make more flexible).
+#   - Add Vector Writers other than SVG.
+#   - set the background color!
+#   - Check memory use!!
 #
 # ---------------------------------------------------------------------
 
 import Blender
-from Blender import Scene, Object, Mesh, NMesh, Lamp, Camera
+from Blender import Scene, Object, Mesh, NMesh, Material, Lamp, Camera, Window
 from Blender.Mathutils import *
 from math import *
+import sys
+import time
 
+try:
+    set()
+except NameError:
+    from sets import Set as set
 
-# ---------------------------------------------------------------------
-#
-## Projections classes
-#
-# ---------------------------------------------------------------------
 
-class Projector:
-    """Calculate the projection of an object given the camera.
-    
-    A projector is useful to so some per-object transformation to obtain the
-    projection of an object given the camera.
-    
-    The main method is #doProjection# see the method description for the
-    parameter list.
-    """
+def uniq(alist):
+    tmpdict = dict()
+    return [tmpdict.setdefault(e, e) for e in alist if e not in tmpdict]
+    # in python > 2.4 we ca use the following
+    #return [ u for u in alist if u not in locals()['_[1]'] ]
 
-    def __init__(self, cameraObj, canvasRatio):
-        """Calculate the projection matrix.
 
-        The projection matrix depends, in this case, on the camera settings,
-        and also on object transformation matrix.
-        """
+# Constants
+EPS = 10e-5
 
-        camera = cameraObj.getData()
+# We use a global progress Indicator Object
+progress = None
 
-        aspect = float(canvasRatio[0])/float(canvasRatio[1])
-        near = camera.clipStart
-        far = camera.clipEnd
 
-        fovy = atan(0.5/aspect/(camera.lens/32))
-        fovy = fovy * 360/pi
-        
-        # What projection do we want?
-        if camera.type:
-            m2 = self._calcOrthoMatrix(fovy, aspect, near, far, 17) #camera.scale) 
-        else:
-            m2 = self._calcPerspectiveMatrix(fovy, aspect, near, far) 
-        
+# Config class for global settings
 
-        # View transformation
-        cam = Matrix(cameraObj.getInverseMatrix())
-        cam.transpose() 
-        
-        # FIXME: remove the commented part, we used to pass object in local
-        # coordinates, but this is not very clean, we should apply modelview
-        # tranformations _before_ (at some other level).
-        #m1 = Matrix(obMesh.getMatrix())
-        #m1.transpose()
-        
-        #mP = cam * m1
-        mP = cam
-        mP = m2  * mP
+class config:
+    polygons = dict()
+    polygons['SHOW'] = True
+    polygons['SHADING'] = 'FLAT'  # FLAT or TOON
+    polygons['HSR'] = 'PAINTER'  # PAINTER or NEWELL
+    # Hidden to the user for now
+    polygons['EXPANSION_TRICK'] = True
 
-        self.projectionMatrix = mP
+    polygons['TOON_LEVELS'] = 2
 
-    ##
-    # Public methods
-    #
+    edges = dict()
+    edges['SHOW'] = False
+    edges['SHOW_HIDDEN'] = False
+    edges['STYLE'] = 'MESH'  # MESH or SILHOUETTE
+    edges['WIDTH'] = 2
+    edges['COLOR'] = [0, 0, 0]
 
-    def doProjection(self, v):
-        """Project the point on the view plane.
+    output = dict()
+    output['FORMAT'] = 'SVG'
+    output['ANIMATION'] = False
+    output['JOIN_OBJECTS'] = True
 
-        Given a vertex calculate the projection using the current projection
-        matrix.
-        """
-        
-        # Note that we need the vertex expressed using homogeneous coordinates
-        p = self.projectionMatrix * Vector(v).resize4D()
+    def saveToRegistry():
+        registry = {}
 
-        if p[3]>0:
-            p[0] = p[0]/p[3]
-            p[1] = p[1]/p[3]
+        for k, v in config.__dict__.iteritems():
 
-        return p
+            # config class store settings in dictionaries
+            if v.__class__ == dict().__class__:
 
-    ##
-    # Private methods
-    #
-    
-    def _calcPerspectiveMatrix(self, fovy, aspect, near, far):
-        """Return a perspective projection matrix."""
-        
-        top = near * tan(fovy * pi / 360.0)
-        bottom = -top
-        left = bottom*aspect
-        right= top*aspect
-        x = (2.0 * near) / (right-left)
-        y = (2.0 * near) / (top-bottom)
-        a = (right+left) / (right-left)
-        b = (top+bottom) / (top - bottom)
-        c = - ((far+near) / (far-near))
-        d = - ((2*far*near)/(far-near))
-        
-        m = Matrix(
-                [x,   0.0,    a,    0.0],
-                [0.0,   y,    b,    0.0],
-                [0.0, 0.0,    c,      d],
-                [0.0, 0.0, -1.0,    0.0])
+                regkey_prefix = k.upper() + "_"
 
-        return m
+                for opt_k, opt_v in v.iteritems():
+                    regkey = regkey_prefix + opt_k
 
-    def _calcOrthoMatrix(self, fovy, aspect , near, far, scale):
-        """Return an orthogonal projection matrix."""
-        
-        top = near * tan(fovy * pi / 360.0) * (scale * 10)
-        bottom = -top 
-        left = bottom * aspect
-        right= top * aspect
-        rl = right-left
-        tb = top-bottom
-        fn = near-far 
-        tx = -((right+left)/rl)
-        ty = -((top+bottom)/tb)
-        tz = ((far+near)/fn)
+                    registry[regkey] = opt_v
 
-        m = Matrix(
-                [2.0/rl, 0.0,    0.0,     tx],
-                [0.0,    2.0/tb, 0.0,     ty],
-                [0.0,    0.0,    2.0/fn,  tz],
-                [0.0,    0.0,    0.0,    1.0])
-        
-        return m
+        Blender.Registry.SetKey('VRM', registry, True)
 
+    saveToRegistry = staticmethod(saveToRegistry)
 
-# ---------------------------------------------------------------------
-#
-## Object representation class
-#
-# ---------------------------------------------------------------------
+    def loadFromRegistry():
+        registry = Blender.Registry.GetKey('VRM', True)
+        if not registry:
+            return
 
-# TODO: a class to represent the needed properties of a 2D vector image
-# Just use a NMesh structure?
+        for k, v in registry.iteritems():
+            k_tmp = k.split('_')
+            conf_attr = k_tmp[0].lower()
+            conf_key = str.join("_", k_tmp[1:])
+            conf_val = v
 
+            if conf_attr in config.__dict__:
+                config.__dict__[conf_attr][conf_key] = conf_val
 
-# ---------------------------------------------------------------------
-#
-## Vector Drawing Classes
-#
-# ---------------------------------------------------------------------
+    loadFromRegistry = staticmethod(loadFromRegistry)
 
-## A generic Writer
 
-class VectorWriter:
-    """
-    A class for printing output in a vectorial format.
+# Utility functions
+print_debug = False
 
-    Given a 2D representation of the 3D scene the class is responsible to
-    write it is a vector format.
 
-    Every subclasses of VectorWriter must have at last the following public
-    methods:
-        - printCanvas(mesh) --- where mesh is as specified before.
+def dumpfaces(flist, filename):
+    """Dump a single face to a file.
     """
-    
-    def __init__(self, fileName):
-        """Open the file named #fileName# and set the canvas size."""
-        
-        self.file = open(fileName, "w")
-        print "Outputting to: ", fileName
+    if not print_debug:
+        return
 
+    class tmpmesh:
+        pass
 
-        context = Scene.GetCurrent().getRenderingContext()
-        self.canvasSize = ( context.imageSizeX(), context.imageSizeY() )
-    
+    m = tmpmesh()
+    m.faces = flist
 
-    ##
-    # Public Methods
-    #
-    
-    def printCanvas(mesh):
-        return
-        
-    ##
-    # Private Methods
-    #
-    
-    def _printHeader():
-        return
+    writerobj = SVGVectorWriter(filename)
 
-    def _printFooter():
-        return
+    writerobj.open()
+    writerobj._printPolygons(m)
 
+    writerobj.close()
 
-## SVG Writer
 
-class SVGVectorWriter(VectorWriter):
-    """A concrete class for writing SVG output.
+def debug(msg):
+    if print_debug:
+        sys.stderr.write(msg)
 
-    The class does not support animations, yet.
-    Sorry.
-    """
 
-    def __init__(self, file):
-        """Simply call the parent Contructor."""
-        VectorWriter.__init__(self, file)
+def EQ(v1, v2):
+    return (abs(v1[0] - v2[0]) < EPS and
+            abs(v1[1] - v2[1]) < EPS)
+by_furthest_z = (lambda f1, f2:
+    cmp(max([v.co[2] for v in f1]), max([v.co[2] for v in f2]) + EPS)
+    )
 
 
-    ##
-    # Public Methods
-    #
+def sign(x):
 
-    def open(self):
-        self._printHeader()
+    if x < -EPS:
+    #if x < 0:
+        return -1
+    elif x > EPS:
+    #elif x > 0:
+        return 1
+    else:
+        return 0
 
-    def close(self):
-        self._printFooter()
 
-        
-    
-    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False, showHiddenEdges=False):
-        """Convert the scene representation to SVG."""
+# ---------------------------------------------------------------------
+#
+## HSR Utility class
+#
+# ---------------------------------------------------------------------
 
-        Objects = scene.getChildren()
-        for obj in Objects:
+EPS = 10e-5
+INF = 10e5
 
-            if(obj.getType() != 'Mesh'):
-                continue
-            #
 
-            self.file.write("<g>\n")
+class HSR:
+    """A utility class for HSR processing.
+    """
 
-            
-            if doPrintPolygons:
-                for face in obj.getData().faces:
-                    self._printPolygon(face)
+    def is_nonplanar_quad(face):
+        """Determine if a quad is non-planar.
 
-            if doPrintEdges:
-                self._printEdges(obj.getData(), showHiddenEdges)
-            
-            self.file.write("</g>\n")
-        
-    
-    ##  
-    # Private Methods
-    #
-    
-    def _printHeader(self):
-        """Print SVG header."""
+        From: http://mathworld.wolfram.com/Coplanar.html
 
-        self.file.write("<?xml version=\"1.0\"?>\n")
-        self.file.write("<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.1//EN\"\n")
-        self.file.write("\t\"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd\">\n")
-        self.file.write("<svg version=\"1.1\"\n")
-        self.file.write("\txmlns=\"http://www.w3.org/2000/svg\"\n")
-        self.file.write("\twidth=\"%d\" height=\"%d\" streamable=\"true\">\n\n" %
-                self.canvasSize)
+        Geometric objects lying in a common plane are said to be coplanar.
+        Three noncollinear points determine a plane and so are trivially
+        coplanar. Four points are coplanar iff the volume of the tetrahedron
+        defined by them is 0,
 
-    def _printFooter(self):
-        """Print the SVG footer."""
+            | x_1 y_1 z_1 1 |
+            | x_2 y_2 z_2 1 |
+            | x_3 y_3 z_3 1 |
+            | x_4 y_4 z_4 1 | == 0
 
-        self.file.write("\n</svg>\n")
-        self.file.close()
+        Coplanarity is equivalent to the statement that the pair of lines
+        determined by the four points are not skew, and can be equivalently
+        stated in vector form as (x_3-x_1).[(x_2-x_1)x(x_4-x_3)]==0.
 
-    def _printEdges(self, mesh, showHiddenEdges=False):
-        """Print the wireframe using mesh edges... is this the correct way?
+        An arbitrary number of n points x_1, ..., x_n can be tested for
+        coplanarity by finding the point-plane distances of the points
+        x_4, ..., x_n from the plane determined by (x_1,x_2,x_3)
+        and checking if they are all zero.
+        If so, the points are all coplanar.
+
+        We here check only for 4-point complanarity.
         """
+        n = len(face)
 
-        stroke_width=0.5
-        stroke_col = [0, 0, 0]
-        
-        self.file.write("<g>\n")
+        # assert(n>4)
+        if n < 3 or n > 4:
+            print "ERROR a mesh in Blender can't have more than 4 vertices or less than 3"
+            raise AssertionError
 
-        for e in mesh.edges:
-            
-            hidden_stroke_style = ""
-            
-            # And edge is selected if both vertives are selected
-            if e.v1.sel == 0 or e.v2.sel == 0:
-                if showHiddenEdges == False:
-                    continue
-                else:
-                    hidden_stroke_style = ";\n stroke-dasharray:3, 3"
+        elif n == 3:
+            # three points must be complanar
+            return False
+        else:  # n == 4
+            x1 = Vector(face[0].co)
+            x2 = Vector(face[1].co)
+            x3 = Vector(face[2].co)
+            x4 = Vector(face[3].co)
 
-            p1 = self._calcCanvasCoord(e.v1)
-            p2 = self._calcCanvasCoord(e.v2)
-            
-            self.file.write("<line x1=\"%g\" y1=\"%g\" x2=\"%g\" y2=\"%g\"\n"
-                    % ( p1[0], p1[1], p2[0], p2[1] ) )
-            self.file.write(" style=\"stroke:rgb("+str(stroke_col[0])+","+str(stroke_col[1])+","+str(stroke_col[2])+");")
-            self.file.write(" stroke-width:"+str(stroke_width)+";\n")
-            self.file.write(" stroke-linecap:round;stroke-linejoin:round")
-            self.file.write(hidden_stroke_style)
-            self.file.write("\"/>\n")
+            v = (x3 - x1) * CrossVecs((x2 - x1), (x4 - x3))
+            if v != 0:
+                return True
 
-        self.file.write("</g>\n")
-            
-        
-
-    def _printPolygon(self, face):
-        """Print our primitive, finally.
-        """
-
-        wireframe = False
-        
-        stroke_width=0.5
-        
-        self.file.write("<polygon points=\"")
-
-        for v in face:
-            p = self._calcCanvasCoord(v)
-            self.file.write("%g,%g " % (p[0], p[1]))
-        
-        self.file.seek(-1,1) # get rid of the last space
-        self.file.write("\"\n")
-        
-        #take as face color the first vertex color
-        if face.col:
-            fcol = face.col[0]
-            color = [fcol.r, fcol.g, fcol.b]
-        else:
-            color = [ 255, 255, 255]
+        return False
 
-        stroke_col = [0, 0, 0]
-        if not wireframe:
-            stroke_col = color
+    is_nonplanar_quad = staticmethod(is_nonplanar_quad)
 
-        self.file.write("\tstyle=\"fill:rgb("+str(color[0])+","+str(color[1])+","+str(color[2])+");")
-        self.file.write(" stroke:rgb("+str(stroke_col[0])+","+str(stroke_col[1])+","+str(stroke_col[2])+");")
-        self.file.write(" stroke-width:"+str(stroke_width)+";\n")
-        self.file.write(" stroke-linecap:round;stroke-linejoin:round")
-        self.file.write("\"/>\n")
+    def pointInPolygon(poly, v):
+        return False
 
-    def _calcCanvasCoord(self, v):
+    pointInPolygon = staticmethod(pointInPolygon)
 
-        pt = Vector([0, 0, 0])
-        
-        mW = self.canvasSize[0]/2
-        mH = self.canvasSize[1]/2
+    def edgeIntersection(s1, s2, do_perturbate=False):
 
-        # rescale to canvas size
-        pt[0] = round(v[0]*mW)+mW
-        pt[1] = round(v[1]*mH)+mH
-         
-        # For now we want (0,0) in the top-left corner of the canvas
-        # Mirror and translate along y
-        pt[1] *= -1
-        pt[1] += self.canvasSize[1]
-        
-        return pt
+        (x1, y1) = s1[0].co[0], s1[0].co[1]
+        (x2, y2) = s1[1].co[0], s1[1].co[1]
 
+        (x3, y3) = s2[0].co[0], s2[0].co[1]
+        (x4, y4) = s2[1].co[0], s2[1].co[1]
 
-# ---------------------------------------------------------------------
-#
-## Rendering Classes
-#
-# ---------------------------------------------------------------------
+        #z1 = s1[0].co[2]
+        #z2 = s1[1].co[2]
+        #z3 = s2[0].co[2]
+        #z4 = s2[1].co[2]
 
-class Renderer:
-    """Render a scene viewed from a given camera.
-    
-    This class is responsible of the rendering process, hence transformation
-    and projection of the ojects in the scene are invoked by the renderer.
+        # calculate delta values (vector components)
+        dx1 = x2 - x1
+        dx2 = x4 - x3
+        dy1 = y2 - y1
+        dy2 = y4 - y3
 
-    The user can optionally provide a specific camera for the rendering, see
-    the #doRendering# method for more informations.
-    """
+        #dz1 = z2 - z1
+        #dz2 = z4 - z3
 
-    def __init__(self):
-        """Make the rendering process only for the current scene by default.
-        """
+        C = dy2 * dx1 - dx2 * dy1  # cross product
+        if C == 0:  # parallel
+            return None
 
-        # Render the current Scene set as a READ-ONLY property
-        self._SCENE = Scene.GetCurrent()
-        
-        # Use the aspect ratio of the scene rendering context
-        context = self._SCENE.getRenderingContext()
-        self.canvasRatio = (context.aspectRatioX(), context.aspectRatioY())
+        dx3 = x1 - x3  # combined origin offset vector
+        dy3 = y1 - y3
 
-        # Render from the currently active camera 
-        self.camera = self._SCENE.getCurrentCamera()
+        a1 = (dy3 * dx2 - dx3 * dy2) / C
+        a2 = (dy3 * dx1 - dx3 * dy1) / C
 
+        # check for degeneracies
+        #print_debug("\n")
+        #print_debug(str(a1)+"\n")
+        #print_debug(str(a2)+"\n\n")
 
-    ##
-    # Public Methods
-    #
+        if (a1 == 0 or a1 == 1 or a2 == 0 or a2 == 1):
+            # Intersection on boundaries, we consider the point external?
+            return None
 
-    def doRendering(self, outputWriter, animation=0):
-        """Render picture or animation and write it out.
-        
-        The parameters are:
-            - a Vector writer object than will be used to output the result.
-            - a flag to tell if we want to render an animation or the only
-              current frame.
-        """
-        
-        context = self._SCENE.getRenderingContext()
-        currentFrame = context.currentFrame()
+        elif (a1 > 0.0 and a1 < 1.0 and a2 > 0.0 and a2 < 1.0):  # lines cross
+            x = x1 + a1 * dx1
+            y = y1 + a1 * dy1
+
+            #z = z1 + a1 * dz1
+            z = 0
+            return (NMesh.Vert(x, y, z), a1, a2)
 
-        # Handle the animation case
-        if animation == 0:
-            startFrame = currentFrame
-            endFrame = startFrame
         else:
-            startFrame = context.startFrame()
-            endFrame = context.endFrame()
-        
-        # Do the rendering process frame by frame
-        print "Start Rendering!"
-        for f in range(startFrame, endFrame+1):
-            context.currentFrame(f)
-            renderedScene = self.doRenderScene(self._SCENE)
-            outputWriter.printCanvas(renderedScene,
-                    doPrintPolygons=False, doPrintEdges=True, showHiddenEdges=True)
-            
-            # clear the rendered scene
-            self._SCENE.makeCurrent()
-            Scene.unlink(renderedScene)
-            del renderedScene
+            # lines have intersections but not those segments
+            return None
 
-        print "Done!"
-        context.currentFrame(currentFrame)
+    edgeIntersection = staticmethod(edgeIntersection)
 
+    def isVertInside(self, v):
+        winding_number = 0
+        coincidence = False
 
+        # Create point at infinity
+        point_at_infinity = NMesh.Vert(-INF, v.co[1], -INF)
 
-    def doRenderScene(self, inputScene):
-        """Control the rendering process.
-        
-        Here we control the entire rendering process invoking the operation
-        needed to transform and project the 3D scene in two dimensions.
-        """
-        
-        # Use some temporary workspace, a full copy of the scene
-        workScene = inputScene.copy(2)
+        for i in range(len(self.v)):
+            s1 = (point_at_infinity, v)
+            s2 = (self.v[i - 1], self.v[i])
 
-        # Get a projector for this scene.
-        # NOTE: the projector wants object in world coordinates,
-        # so we should apply modelview transformations _before_
-        # projection transformations
-        proj = Projector(self.camera, self.canvasRatio)
-            
-        # global processing of the scene
-        self._doDepthSorting(workScene)
-        
-        # Per object activities
-        Objects = workScene.getChildren()
-        
-        for obj in Objects:
-            
-            if (obj.getType() != 'Mesh'):
-                print "Type:", obj.getType(), "\tSorry, only mesh Object supported!"
-                continue
-            #
+            if EQ(v.co, s2[0].co) or EQ(v.co, s2[1].co):
+                coincidence = True
 
-            self._doModelViewTransformations(obj)
+            if HSR.edgeIntersection(s1, s2, do_perturbate=False):
+                winding_number += 1
 
-            self._doBackFaceCulling(obj)
-            
-            self._doColorAndLighting(obj)
+        # Check even or odd
+        if (winding_number % 2) == 0:
+            return False
+        else:
+            if coincidence:
+                return False
+            return True
 
-            # 'style' can be a function that determine
-            # if an edge should be showed?
-            self._doEdgesStyle(obj, style=None)
-           
-            self._doProjection(obj, proj)
+    isVertInside = staticmethod(isVertInside)
 
-        return workScene
+    def det(a, b, c):
+        return ((b[0] - a[0]) * (c[1] - a[1]) -
+                (b[1] - a[1]) * (c[0] - a[0]))
 
+    det = staticmethod(det)
 
-    def oldRenderScene(scene):
-        
-        # Per object activities
-        Objects = workScene.getChildren()
-        
-        for obj in Objects:
-            
-            if (obj.getType() != 'Mesh'):
-                print "Type:", obj.getType(), "\tSorry, only mesh Object supported!"
-                continue
-            
-            # Get a projector for this object
-            proj = Projector(self.camera, obj, self.canvasSize)
-
-            # Let's store the transformed data
-            transformed_mesh = NMesh.New("flat"+obj.name)
-            transformed_mesh.hasVertexColours(1)
-
-            # process Edges
-            self._doProcessEdges(obj)
-            
-            for v in obj.getData().verts:
-                transformed_mesh.verts.append(v)
-            transformed_mesh.edges = self._processEdges(obj.getData().edges)
-            #print transformed_mesh.edges
-
-            
-            # Store the materials
-            materials = obj.getData().getMaterials()
-
-            meshfaces = obj.getData().faces
-
-            for face in meshfaces:
-
-                # if the face is visible flatten it on the "picture plane"
-                if self._isFaceVisible(face, obj, cameraObj):
-                    
-                    # Store transformed face
-                    newface = NMesh.Face()
-
-                    for vert in face:
-
-                        p = proj.doProjection(vert.co)
-
-                        tmp_vert = NMesh.Vert(p[0], p[1], p[2])
-
-                        # Add the vert to the mesh
-                        transformed_mesh.verts.append(tmp_vert)
-                        
-                        newface.v.append(tmp_vert)
-                        
-                    
-                    # Per-face color calculation
-                    # code taken mostly from the original vrm script
-                    # TODO: understand the code and rewrite it clearly
-                    ambient = -150
-                    
-                    fakelight = Object.Get("Lamp").loc
-                    if fakelight == None:
-                        fakelight = [1.0, 1.0, -0.3]
-
-                    norm = Vector(face.no)
-                    vektori = (norm[0]*fakelight[0]+norm[1]*fakelight[1]+norm[2]*fakelight[2])
-                    vduzine = fabs(sqrt(pow(norm[0],2)+pow(norm[1],2)+pow(norm[2],2))*sqrt(pow(fakelight[0],2)+pow(fakelight[1],2)+pow(fakelight[2],2)))
-                    intensity = floor(ambient + 200*acos(vektori/vduzine))/200
-                    if intensity < 0:
-                        intensity = 0
-
-                    if materials:
-                        tmp_col = materials[face.mat].getRGBCol()
-                    else:
-                        tmp_col = [0.5, 0.5, 0.5]
-                        
-                    tmp_col = [ (c>intensity) and int(round((c-intensity)*10)*25.5) for c in tmp_col ]
-
-                    vcol = NMesh.Col(tmp_col[0], tmp_col[1], tmp_col[2])
-                    newface.col = [vcol, vcol, vcol, 255]
-                    
-                    transformed_mesh.addFace(newface)
-
-            # at the end of the loop on obj
-            
-            transformed_obj = Object.New(obj.getType(), "flat"+obj.name)
-            transformed_obj.link(transformed_mesh)
-            transformed_obj.loc = obj.loc
-            newscene.link(transformed_obj)
-
-        
-        return workScene
+    def pointInPolygon(q, P):
+        is_in = False
 
+        point_at_infinity = NMesh.Vert(-INF, q.co[1], -INF)
 
-    ##
-    # Private Methods
-    #
+        det = HSR.det
 
-    # Faces methods
+        for i in range(len(P.v)):
+            p0 = P.v[i - 1]
+            p1 = P.v[i]
+            if (det(q.co, point_at_infinity.co, p0.co) < 0) != (det(q.co, point_at_infinity.co, p1.co) < 0):
+                if det(p0.co, p1.co, q.co) == 0:
+                    #print "On Boundary"
+                    return False
+                elif (det(p0.co, p1.co, q.co) < 0) != (det(p0.co, p1.co, point_at_infinity.co) < 0):
+                    is_in = not is_in
 
-    def _isFaceVisible(self, face, obj, camObj):
-        """Determine if a face of an object is visible from a given camera.
-        
-        The normals need to be transformed, but note that we should apply only the
-        rotation part of the tranformation matrix, since the normals are
-        normalized and they can be intended as starting from the origin.
+        return is_in
 
-        The view vector is calculated from the camera location and one of the
-        vertices of the face (expressed in World coordinates, after applying
-        modelview transformations).
+    pointInPolygon = staticmethod(pointInPolygon)
 
-        After those transformations we determine if a face is visible by computing
-        the angle between the face normal and the view vector, this angle
-        corresponds somehow to the dot product between the two. If the product
-        results <= 0 then the angle between the two vectors is less that 90
-        degrees and then the face is visible.
+    def projectionsOverlap(f1, f2):
+        """ If you have nonconvex, but still simple polygons, an acceptable method
+        is to iterate over all vertices and perform the Point-in-polygon test[1].
+        The advantage of this method is that you can compute the exact
+        intersection point and collision normal that you will need to simulate
+        collision. When you have the point that lies inside the other polygon, you
+        just iterate over all edges of the second polygon again and look for edge
+        intersections. Note that this method detects collsion when it already
+        happens. This algorithm is fast enough to perform it hundreds of times per
+        sec.  """
 
-        There is no need to normalize those vectors since we are only interested in
-        the sign of the cross product and not in the product value.
-        """
+        for i in range(len(f1.v)):
 
-        # The transformation matrix of the object
-        mObj = Matrix(obj.getMatrix())
-        mObj.transpose()
+            # If a point of f1 in inside f2, there is an overlap!
+            v1 = f1.v[i]
+            #if HSR.isVertInside(f2, v1):
+            if HSR.pointInPolygon(v1, f2):
+                return True
 
-        # The normal after applying the current object rotation
-        #normal = mObj.rotationPart() * Vector(face.no)
-        normal = Vector(face.no)
+            # If not the polygon can be ovelap as well, so we check for
+            # intersection between an edge of f1 and all the edges of f2
 
-        # View vector in orthographics projections can be considered simply s the
-        # camera position
-        #view_vect = Vector(camObj.loc)
-
-        # View vector as in perspective projections
-        # it is the dofference between the camera position and
-        # one point of the face, we choose the first point,
-        # but maybe a better choice may be the farthest point from the camera.
-        point = Vector(face[0].co)
-        #point = mObj * point.resize4D()
-        #point.resize3D()
-        view_vect = Vector(camObj.loc) - point
-        
-
-        # if d <= 0 the face is visible from the camera
-        d = view_vect * normal
-        
-        if d <= 0:
-            return False
-        else:
-            return True
+            v0 = f1.v[i - 1]
 
+            for j in range(len(f2.v)):
+                v2 = f2.v[j - 1]
+                v3 = f2.v[j]
 
-    # Scene methods
+                e1 = v0, v1
+                e2 = v2, v3
 
-    def _doClipping():
-        return
+                intrs = HSR.edgeIntersection(e1, e2)
+                if intrs:
+                    #print_debug(str(v0.co) + " " + str(v1.co) + " " +
+                    #        str(v2.co) + " " + str(v3.co) )
+                    #print_debug("\nIntersection\n")
+
+                    return True
+
+        return False
+
+    projectionsOverlap = staticmethod(projectionsOverlap)
 
-    def _doDepthSorting(self, scene):
+    def midpoint(p1, p2):
+        """Return the midpoint of two vertices.
+        """
+        m = MidpointVecs(Vector(p1), Vector(p2))
+        mv = NMesh.Vert(m[0], m[1], m[2])
+
+        return mv
 
-        cameraObj = self.camera
-        Objects = scene.getChildren()
+    midpoint = staticmethod(midpoint)
+
+    def facesplit(P, Q, facelist, nmesh):
+        """Split P or Q according to the strategy illustrated in the Newell's
+        paper.
+        """
 
-        Objects.sort(lambda obj1, obj2: 
-                cmp(Vector(Vector(cameraObj.loc) - Vector(obj1.loc)).length,
-                    Vector(Vector(cameraObj.loc) - Vector(obj2.loc)).length
-                    )
+        by_furthest_z = (lambda f1, f2:
+                cmp(max([v.co[2] for v in f1]), max([v.co[2] for v in f2]) + EPS)
                 )
-        
-        # hackish sorting of faces according to the max z value of a vertex
-        for o in Objects:
 
-            if (o.getType() != 'Mesh'):
-                continue
+        # Choose if split P on Q plane or vice-versa
+
+        n = 0
+        for Pi in P:
+            d = HSR.Distance(Vector(Pi), Q)
+            if d <= EPS:
+                n += 1
+        pIntersectQ = (n != len(P))
+
+        n = 0
+        for Qi in Q:
+            d = HSR.Distance(Vector(Qi), P)
+            if d >= -EPS:
+                n += 1
+        qIntersectP = (n != len(Q))
+
+        newfaces = []
+
+        # 1. If parts of P lie in both half-spaces of Q
+        # then splice P in two with the plane of Q
+        if pIntersectQ:
+            #print "We split P"
+            f = P
+            plane = Q
+
+            newfaces = HSR.splitOn(plane, f)
+
+        # 2. Else if parts of Q lie in both half-space of P
+        # then splice Q in two with the plane of P
+        if qIntersectP and newfaces == None:
+            #print "We split Q"
+            f = Q
+            plane = P
+
+            newfaces = HSR.splitOn(plane, f)
+            #print "After"
+
+        # 3. Else slice P in half through the mid-point of
+        # the longest pair of opposite sides
+        if newfaces == None:
+
+            print "We ignore P..."
+            facelist.remove(P)
+            return facelist
+
+            #f = P
+
+            #if len(P)==3:
+            #    v1 = midpoint(f[0], f[1])
+            #    v2 = midpoint(f[1], f[2])
+            #if len(P)==4:
+            #    v1 = midpoint(f[0], f[1])
+            #    v2 = midpoint(f[2], f[3])
+            #vec3 = (Vector(v2)+10*Vector(f.normal))
             #
+            #v3 = NMesh.Vert(vec3[0], vec3[1], vec3[2])
 
-            mesh = o.data
-            mesh.faces.sort(
-                lambda f1, f2:
-                    # Sort faces according to the min z coordinate in a face
-                    #cmp(min([v[2] for v in f1]), min([v[2] for v in f2])))
-
-                    # Sort faces according to the max z coordinate in a face
-                    cmp(max([v[2] for v in f1]), max([v[2] for v in f2])))
-                    
-                    # Sort faces according to the avg z coordinate in a face
-                    #cmp(sum([v[2] for v in f1])/len(f1), sum([v[2] for v in f2])/len(f2)))
-            mesh.faces.reverse()
-            mesh.update()
-            
-        # update the scene
-        # FIXME: check if it is correct
-        scene.update()
-        #for o in scene.getChildren():
-        #     scene.unlink(o)
-        #for o in Objects:
-        #   scene.link(o)
-
-    # Per object methods
+            #plane = NMesh.Face([v1, v2, v3])
+            #
+            #newfaces = splitOn(plane, f)
 
-    def _doModelViewTransformations(self, object):
-        if(object.getType() != 'Mesh'):
-            return
-        
-        matMV = object.matrix
-        mesh = object.data
-        mesh.transform(matMV, True)
-        mesh.update()
+        if newfaces == None:
+            print "Big FAT problem, we weren't able to split POLYGONS!"
+            raise AssertionError
 
+        #print newfaces
+        if newfaces:
+            #for v in f:
+            #    if v not in plane and v in nmesh.verts:
+            #        nmesh.verts.remove(v)
+            for nf in newfaces:
 
-    def _doBackFaceCulling(self, object):
-        if(object.getType() != 'Mesh'):
-            return
-        
-        print "doing Backface Culling"
-        mesh = object.data
-        
-        # Select all vertices, so edges without faces can be displayed
-        for v in mesh.verts:
-            v.sel = 1
-        
-        Mesh.Mode(Mesh.SelectModes['FACE'])
-        # Loop on faces
-        for f in mesh.faces:
-            f.sel = 0
-            if self._isFaceVisible(f, object, self.camera):
-                f.sel = 1
+                nf.mat = f.mat
+                nf.sel = f.sel
+                nf.col = [f.col[0]] * len(nf.v)
 
-        for f in mesh.faces:
-            if not f.sel:
-                for v in f:
-                    v.sel = 0
+                nf.smooth = 0
 
-        for f in mesh.faces:
-            if f.sel:
-                for v in f:
-                    v.sel = 1
+                for v in nf:
+                    nmesh.verts.append(v)
+                # insert pieces in the list
+                facelist.append(nf)
 
-        mesh.update()
+            facelist.remove(f)
 
-        
+        # and resort the faces
+        facelist.sort(by_furthest_z)
+        facelist.sort(lambda f1, f2: cmp(f1.smooth, f2.smooth))
+        facelist.reverse()
 
-        #Mesh.Mode(Mesh.SelectModes['VERTEX'])
+        #print [ f.smooth for f in facelist ]
 
-    def _doColorAndLighting(self, object):
-        return
+        return facelist
 
-    def _doEdgesStyle(self, object, style):
-        """Process Mesh Edges. (For now copy the edge data, in next version it
-        can be a place where recognize silouhettes and/or contours).
+    facesplit = staticmethod(facesplit)
 
-        input: an edge list
-        return: a processed edge list
+    def isOnSegment(v1, v2, p, extremes_internal=False):
+        """Check if point p is in segment v1v2.
         """
-        return
 
-    def _doProjection(self, object, projector):
+        l1 = (v1 - p).length
+        l2 = (v2 - p).length
 
-        if(object.getType() != 'Mesh'):
-            return
-        
-        mesh = object.data
-        for v in mesh.verts:
-            p = projector.doProjection(v.co)
-            v[0] = p[0]
-            v[1] = p[1]
-            v[2] = p[2]
-        mesh.update()
+        # Should we consider extreme points as internal ?
+        # The test:
+        # if p == v1 or p == v2:
+        if l1 < EPS or l2 < EPS:
+            return extremes_internal
 
+        l = (v1 - v2).length
 
+        # if the sum of l1 and l2 is circa l, then the point is on segment,
+        if abs(l - (l1 + l2)) < EPS:
+            return True
+        else:
+            return False
 
-# ---------------------------------------------------------------------
-#
-## Main Program
-#
-# ---------------------------------------------------------------------
+    isOnSegment = staticmethod(isOnSegment)
 
+    def Distance(point, face):
+        """ Calculate the distance between a point and a face.
 
-# FIXME: really hackish code, just to test if the other parts work
-    
-def vectorize(filename):
-    """The vectorizing process is as follows:
-     
-     - Open the writer
-     - Render the scene
-     - Close the writer
-     
-     If you want to render an animation the second pass should be
-     repeated for any frame, and the frame number should be passed to the
-     renderer.
-     """
-    writer = SVGVectorWriter(filename)
-    
-    writer.open()
-    
-    renderer = Renderer()
-    renderer.doRendering(writer)
+        An alternative but more expensive method can be:
 
-    writer.close()
+            ip = Intersect(Vector(face[0]), Vector(face[1]), Vector(face[2]),
+                    Vector(face.no), Vector(point), 0)
 
+            d = Vector(ip - point).length
 
-# Here the main
-if __name__ == "__main__":
-    # with this trick we can run the script in batch mode
-    try:
-        Blender.Window.FileSelector (vectorize, 'Save SVG', "proba.svg")
-        Blender.Redraw()
-    except:
-        from Blender import Window
-        editmode = Window.EditMode()
-        if editmode: Window.EditMode(0)
+        See: http://mathworld.wolfram.com/Point-PlaneDistance.html
+        """
+
+        p = Vector(point)
+        plNormal = Vector(face.no)
+        plVert0 = Vector(face.v[0])
+
+        d = (plVert0 * plNormal) - (p * plNormal)
+
+        #d = plNormal * (plVert0 - p)
+
+        #print "\nd: %.10f - sel: %d, %s\n" % (d, face.sel, str(point))
+
+        return d
+
+    Distance = staticmethod(Distance)
+
+    def makeFaces(vl):
+        #
+        # make one or two new faces based on a list of vertex-indices
+        #
+        newfaces = []
+
+        if len(vl) <= 4:
+            nf = NMesh.Face()
+
+            for v in vl:
+                nf.v.append(v)
+
+            newfaces.append(nf)
+
+        else:
+            nf = NMesh.Face()
+
+            nf.v.append(vl[0])
+            nf.v.append(vl[1])
+            nf.v.append(vl[2])
+            nf.v.append(vl[3])
+            newfaces.append(nf)
+
+            nf = NMesh.Face()
+            nf.v.append(vl[3])
+            nf.v.append(vl[4])
+            nf.v.append(vl[0])
+            newfaces.append(nf)
+
+        return newfaces
+
+    makeFaces = staticmethod(makeFaces)
+
+    def splitOn(Q, P, return_positive_faces=True, return_negative_faces=True):
+        """Split P using the plane of Q.
+        Logic taken from the knife.py python script
+        """
+
+        # Check if P and Q are parallel
+        u = CrossVecs(Vector(Q.no), Vector(P.no))
+        ax = abs(u[0])
+        ay = abs(u[1])
+        az = abs(u[2])
+
+        if (ax + ay + az) < EPS:
+            print "PARALLEL planes!!"
+            return
+
+        # The final aim is to find the intersection line between P
+        # and the plane of Q, and split P along this line
+
+        nP = len(P.v)
+
+        # Calculate point-plane Distance between vertices of P and plane Q
+        d = []
+        for i in range(0, nP):
+            d.append(HSR.Distance(P.v[i], Q))
+
+        newVertList = []
+
+        posVertList = []
+        negVertList = []
+        for i in range(nP):
+            d0 = d[i - 1]
+            V0 = P.v[i - 1]
+
+            d1 = d[i]
+            V1 = P.v[i]
+
+            #print "d0:", d0, "d1:", d1
+
+            # if the vertex lies in the cutplane
+            if abs(d1) < EPS:
+                #print "d1 On cutplane"
+                posVertList.append(V1)
+                negVertList.append(V1)
+            else:
+                # if the previous vertex lies in cutplane
+                if abs(d0) < EPS:
+                    #print "d0 on Cutplane"
+                    if d1 > 0:
+                        #print "d1 on positive Halfspace"
+                        posVertList.append(V1)
+                    else:
+                        #print "d1 on negative Halfspace"
+                        negVertList.append(V1)
+                else:
+                    # if they are on the same side of the plane
+                    if (d1 * d0) > 0:
+                        #print "On the same half-space"
+                        if d1 > 0:
+                            #print "d1 on positive Halfspace"
+                            posVertList.append(V1)
+                        else:
+                            #print "d1 on negative Halfspace"
+                            negVertList.append(V1)
+
+                    # the vertices are not on the same side of the plane, so we have an intersection
+                    else:
+                        #print "Intersection"
+
+                        e = Vector(V0), Vector(V1)
+                        tri = Vector(Q[0]), Vector(Q[1]), Vector(Q[2])
+
+                        inters = Intersect(tri[0], tri[1], tri[2], e[1] - e[0], e[0], 0)
+                        if inters == None:
+                            print "Split Break"
+                            break
+
+                        #print "Intersection", inters
+
+                        nv = NMesh.Vert(inters[0], inters[1], inters[2])
+                        newVertList.append(nv)
+
+                        posVertList.append(nv)
+                        negVertList.append(nv)
+
+                        if d1 > 0:
+                            posVertList.append(V1)
+                        else:
+                            negVertList.append(V1)
+
+        # uniq for python > 2.4
+        #posVertList = [ u for u in posVertList if u not in locals()['_[1]'] ]
+        #negVertList = [ u for u in negVertList if u not in locals()['_[1]'] ]
+
+        # a more portable way
+        posVertList = uniq(posVertList)
+        negVertList = uniq(negVertList)
+
+        # If vertex are all on the same half-space, return
+        #if len(posVertList) < 3:
+        #    print "Problem, we created a face with less that 3 vertices??"
+        #    posVertList = []
+        #if len(negVertList) < 3:
+        #    print "Problem, we created a face with less that 3 vertices??"
+        #    negVertList = []
+
+        if len(posVertList) < 3 or len(negVertList) < 3:
+            #print "RETURN NONE, SURE???"
+            return None
+
+        if not return_positive_faces:
+            posVertList = []
+        if not return_negative_faces:
+            negVertList = []
+
+        newfaces = HSR.addNewFaces(posVertList, negVertList)
+
+        return newfaces
+
+    splitOn = staticmethod(splitOn)
+
+    def addNewFaces(posVertList, negVertList):
+        # Create new faces resulting from the split
+        outfaces = []
+        if len(posVertList) or len(negVertList):
+
+            #newfaces = [posVertList] + [negVertList]
+            newfaces = ([[NMesh.Vert(v[0], v[1], v[2]) for v in posVertList]] +
+                    [[NMesh.Vert(v[0], v[1], v[2]) for v in negVertList]])
+
+            for nf in newfaces:
+                if nf and len(nf) > 2:
+                    outfaces += HSR.makeFaces(nf)
+
+        return outfaces
+
+    addNewFaces = staticmethod(addNewFaces)
+
+
+# ---------------------------------------------------------------------
+#
+## Mesh Utility class
+#
+# ---------------------------------------------------------------------
+
+class MeshUtils:
+
+    def buildEdgeFaceUsersCache(me):
+        '''
+        Takes a mesh and returns a list aligned with the meshes edges.
+        Each item is a list of the faces that use the edge
+        would be the equiv for having ed.face_users as a property
+
+        Taken from .blender/scripts/bpymodules/BPyMesh.py,
+        thanks to ideasman_42.
+        '''
+
+        def sorted_edge_indicies(ed):
+            i1 = ed.v1.index
+            i2 = ed.v2.index
+            if i1 > i2:
+                i1, i2 = i2, i1
+            return i1, i2
+
+        face_edges_dict = dict([(sorted_edge_indicies(ed), (ed.index, [])) for ed in me.edges])
+        for f in me.faces:
+            fvi = [v.index for v in f.v]  # face vert idx's
+            for i in xrange(len(f)):
+                i1 = fvi[i]
+                i2 = fvi[i - 1]
+
+                if i1 > i2:
+                    i1, i2 = i2, i1
+
+                face_edges_dict[i1, i2][1].append(f)
+
+        face_edges = [None] * len(me.edges)
+        for ed_index, ed_faces in face_edges_dict.itervalues():
+            face_edges[ed_index] = ed_faces
+
+        return face_edges
+
+    def isMeshEdge(adjacent_faces):
+        """Mesh edge rule.
+
+        A mesh edge is visible if _at_least_one_ of its adjacent faces is selected.
+        Note: if the edge has no adjacent faces we want to show it as well,
+        useful for "edge only" portion of objects.
+        """
+
+        if len(adjacent_faces) == 0:
+            return True
+
+        selected_faces = [f for f in adjacent_faces if f.sel]
+
+        if len(selected_faces) != 0:
+            return True
+        else:
+            return False
+
+    def isSilhouetteEdge(adjacent_faces):
+        """Silhuette selection rule.
+
+        An edge is a silhuette edge if it is shared by two faces with
+        different selection status or if it is a boundary edge of a selected
+        face.
+        """
+
+        if ((len(adjacent_faces) == 1 and adjacent_faces[0].sel == 1) or
+            (len(adjacent_faces) == 2 and
+                adjacent_faces[0].sel != adjacent_faces[1].sel)
+            ):
+            return True
+        else:
+            return False
+
+    buildEdgeFaceUsersCache = staticmethod(buildEdgeFaceUsersCache)
+    isMeshEdge = staticmethod(isMeshEdge)
+    isSilhouetteEdge = staticmethod(isSilhouetteEdge)
+
+
+# ---------------------------------------------------------------------
+#
+## Shading Utility class
+#
+# ---------------------------------------------------------------------
+
+class ShadingUtils:
+
+    shademap = None
+
+    def toonShadingMapSetup():
+        levels = config.polygons['TOON_LEVELS']
+
+        texels = 2 * levels - 1
+        tmp_shademap = [0.0] + [(i) / float(texels - 1) for i in xrange(1, texels - 1)] + [1.0]
+
+        return tmp_shademap
+
+    def toonShading(u):
+
+        shademap = ShadingUtils.shademap
+
+        if not shademap:
+            shademap = ShadingUtils.toonShadingMapSetup()
+
+        v = 1.0
+        for i in xrange(0, len(shademap) - 1):
+            pivot = (shademap[i] + shademap[i + 1]) / 2.0
+            j = int(u > pivot)
+
+            v = shademap[i + j]
+
+            if v < shademap[i + 1]:
+                return v
+
+        return v
+
+    toonShadingMapSetup = staticmethod(toonShadingMapSetup)
+    toonShading = staticmethod(toonShading)
+
+
+# ---------------------------------------------------------------------
+#
+## Projections classes
+#
+# ---------------------------------------------------------------------
+
+class Projector:
+    """Calculate the projection of an object given the camera.
+
+    A projector is useful to so some per-object transformation to obtain the
+    projection of an object given the camera.
+
+    The main method is #doProjection# see the method description for the
+    parameter list.
+    """
+
+    def __init__(self, cameraObj, canvasRatio):
+        """Calculate the projection matrix.
+
+        The projection matrix depends, in this case, on the camera settings.
+        TAKE CARE: This projector expects vertices in World Coordinates!
+        """
+
+        camera = cameraObj.getData()
+
+        aspect = float(canvasRatio[0]) / float(canvasRatio[1])
+        near = camera.clipStart
+        far = camera.clipEnd
+
+        scale = float(camera.scale)
+
+        fovy = atan(0.5 / aspect / (camera.lens / 32))
+        fovy = fovy * 360.0 / pi
+
+        if Blender.Get('version') < 243:
+            camPersp = 0
+            camOrtho = 1
+        else:
+            camPersp = 'persp'
+            camOrtho = 'ortho'
+
+        # What projection do we want?
+        if camera.type == camPersp:
+            mP = self._calcPerspectiveMatrix(fovy, aspect, near, far)
+        elif camera.type == camOrtho:
+            mP = self._calcOrthoMatrix(fovy, aspect, near, far, scale)
+
+        # View transformation
+        cam = Matrix(cameraObj.getInverseMatrix())
+        cam.transpose()
+
+        mP = mP * cam
+
+        self.projectionMatrix = mP
+
+    ##
+    # Public methods
+    #
+
+    def doProjection(self, v):
+        """Project the point on the view plane.
+
+        Given a vertex calculate the projection using the current projection
+        matrix.
+        """
+
+        # Note that we have to work on the vertex using homogeneous coordinates
+        # From blender 2.42+ we don't need to resize the vector to be 4d
+        # when applying a 4x4 matrix, but we do that anyway since we need the
+        # 4th coordinate later
+        p = self.projectionMatrix * Vector(v).resize4D()
+
+        # Perspective division
+        if p[3] != 0:
+            p[0] = p[0] / p[3]
+            p[1] = p[1] / p[3]
+            p[2] = p[2] / p[3]
+
+        # restore the size
+        p[3] = 1.0
+        p.resize3D()
+
+        return p
+
+    ##
+    # Private methods
+    #
+
+    def _calcPerspectiveMatrix(self, fovy, aspect, near, far):
+        """Return a perspective projection matrix.
+        """
+
+        top = near * tan(fovy * pi / 360.0)
+        bottom = -top
+        left = bottom * aspect
+        right = top * aspect
+        x = (2.0 * near) / (right - left)
+        y = (2.0 * near) / (top - bottom)
+        a = (right + left) / (right - left)
+        b = (top + bottom) / (top - bottom)
+        c = - ((far + near) / (far - near))
+        d = - ((2 * far * near) / (far - near))
+
+        m = Matrix(
+                [x,   0.0,    a,    0.0],
+                [0.0,   y,    b,    0.0],
+                [0.0, 0.0,    c,      d],
+                [0.0, 0.0, -1.0,    0.0])
+
+        return m
+
+    def _calcOrthoMatrix(self, fovy, aspect, near, far, scale):
+        """Return an orthogonal projection matrix.
+        """
+
+        # The 11 in the formula was found emiprically
+        top = near * tan(fovy * pi / 360.0) * (scale * 11)
+        bottom = -top
+        left = bottom * aspect
+        right = top * aspect
+        rl = right - left
+        tb = top - bottom
+        fn = near - far
+        tx = -((right + left) / rl)
+        ty = -((top + bottom) / tb)
+        tz = ((far + near) / fn)
+
+        m = Matrix(
+                [2.0 / rl, 0.0,      0.0,       tx],
+                [0.0,      2.0 / tb, 0.0,       ty],
+                [0.0,      0.0,      2.0 / fn,  tz],
+                [0.0,      0.0,      0.0,      1.0])
+
+        return m
+
+
+# ---------------------------------------------------------------------
+#
+## Progress Indicator
+#
+# ---------------------------------------------------------------------
+
+class Progress:
+    """A model for a progress indicator.
+
+    Do the progress calculation calculation and
+    the view independent stuff of a progress indicator.
+    """
+    def __init__(self, steps=0):
+        self.name = ""
+        self.steps = steps
+        self.completed = 0
+        self.progress = 0
+
+    def setSteps(self, steps):
+        """Set the number of steps of the activity wich we want to track.
+        """
+        self.steps = steps
+
+    def getSteps(self):
+        return self.steps
+
+    def setName(self, name):
+        """Set the name of the activity wich we want to track.
+        """
+        self.name = name
+
+    def getName(self):
+        return self.name
+
+    def getProgress(self):
+        return self.progress
+
+    def reset(self):
+        self.completed = 0
+        self.progress = 0
+
+    def update(self):
+        """Update the model, call this method when one step is completed.
+        """
+        if self.progress == 100:
+            return False
+
+        self.completed += 1
+        self.progress = (float(self.completed) / float(self.steps)) * 100
+        self.progress = int(self.progress)
+
+        return True
+
+
+class ProgressIndicator:
+    """An abstraction of a View for the Progress Model
+    """
+    def __init__(self):
+
+        # Use a refresh rate so we do not show the progress at
+        # every update, but every 'self.refresh_rate' times.
+        self.refresh_rate = 10
+        self.shows_counter = 0
+
+        self.quiet = False
+
+        self.progressModel = None
+
+    def setQuiet(self, value):
+        self.quiet = value
+
+    def setActivity(self, name, steps):
+        """Initialize the Model.
+
+        In a future version (with subactivities-progress support) this method
+        could only set the current activity.
+        """
+        self.progressModel = Progress()
+        self.progressModel.setName(name)
+        self.progressModel.setSteps(steps)
+
+    def getActivity(self):
+        return self.progressModel
+
+    def update(self):
+        """Update the model and show the actual progress.
+        """
+        assert(self.progressModel)
+
+        if self.progressModel.update():
+            if self.quiet:
+                return
+
+            self.show(self.progressModel.getProgress(),
+                    self.progressModel.getName())
+
+        # We return always True here so we can call the update() method also
+        # from lambda funcs (putting the call in logical AND with other ops)
+        return True
+
+    def show(self, progress, name=""):
+        self.shows_counter = (self.shows_counter + 1) % self.refresh_rate
+        if self.shows_counter != 0:
+            return
+
+        if progress == 100:
+            self.shows_counter = -1
+
+
+class ConsoleProgressIndicator(ProgressIndicator):
+    """Show a progress bar on stderr, a la wget.
+    """
+    def __init__(self):
+        ProgressIndicator.__init__(self)
+
+        self.swirl_chars = ["-", "\\", "|", "/"]
+        self.swirl_count = -1
+
+    def show(self, progress, name):
+        ProgressIndicator.show(self, progress, name)
+
+        bar_length = 70
+        bar_progress = int((progress / 100.0) * bar_length)
+        bar = ("=" * bar_progress).ljust(bar_length)
+
+        self.swirl_count = (self.swirl_count + 1) % len(self.swirl_chars)
+        swirl_char = self.swirl_chars[self.swirl_count]
+
+        progress_bar = "%s |%s| %c %3d%%" % (name, bar, swirl_char, progress)
+
+        sys.stderr.write(progress_bar + "\r")
+        if progress == 100:
+            sys.stderr.write("\n")
+
+
+class GraphicalProgressIndicator(ProgressIndicator):
+    """Interface to the Blender.Window.DrawProgressBar() method.
+    """
+    def __init__(self):
+        ProgressIndicator.__init__(self)
+
+        #self.swirl_chars = ["-", "\\", "|", "/"]
+        # We have to use letters with the same width, for now!
+        # Blender progress bar considers the font widths when
+        # calculating the progress bar width.
+        self.swirl_chars = ["\\", "/"]
+        self.swirl_count = -1
+
+    def show(self, progress, name):
+        ProgressIndicator.show(self, progress)
+
+        self.swirl_count = (self.swirl_count + 1) % len(self.swirl_chars)
+        swirl_char = self.swirl_chars[self.swirl_count]
+
+        progress_text = "%s - %c %3d%%" % (name, swirl_char, progress)
+
+        # Finally draw  the Progress Bar
+        Window.WaitCursor(1)  # Maybe we can move that call in the constructor?
+        Window.DrawProgressBar(progress / 100.0, progress_text)
+
+        if progress == 100:
+            Window.DrawProgressBar(1, progress_text)
+            Window.WaitCursor(0)
+
+# ---------------------------------------------------------------------
+#
+## 2D Object representation class
+#
+# ---------------------------------------------------------------------
+
+# TODO: a class to represent the needed properties of a 2D vector image
+# For now just using a [N]Mesh structure.
+
+
+# ---------------------------------------------------------------------
+#
+## Vector Drawing Classes
+#
+# ---------------------------------------------------------------------
+
+## A generic Writer
+
+class VectorWriter:
+    """
+    A class for printing output in a vectorial format.
+
+    Given a 2D representation of the 3D scene the class is responsible to
+    write it is a vector format.
+
+    Every subclasses of VectorWriter must have at last the following public
+    methods:
+        - open(self)
+        - close(self)
+        - printCanvas(self, scene,
+            doPrintPolygons=True, doPrintEdges=False, showHiddenEdges=False):
+    """
+
+    def __init__(self, fileName):
+        """Set the output file name and other properties"""
+
+        try:
+            config.writer
+        except:
+            config.writer = dict()
+            config.writer['SETTING'] = True
+
+        self.outputFileName = fileName
+
+        context = Scene.GetCurrent().getRenderingContext()
+        self.canvasSize = (context.imageSizeX(), context.imageSizeY())
+
+        self.fps = context.fps
+
+        self.startFrame = 1
+        self.endFrame = 1
+        self.animation = False
+
+    ##
+    # Public Methods
+    #
+
+    def open(self, startFrame=1, endFrame=1):
+        if startFrame != endFrame:
+            self.startFrame = startFrame
+            self.endFrame = endFrame
+            self.animation = True
+
+        print "Outputting to: ", self.outputFileName
+
+        return
+
+    def close(self):
+        return
+
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False,
+            showHiddenEdges=False):
+        """This is the interface for the needed printing routine.
+        """
+        return
+
+
+## SVG Writer
+
+class SVGVectorWriter(VectorWriter):
+    """A concrete class for writing SVG output.
+    """
+
+    def __init__(self, fileName):
+        """Simply call the parent Contructor.
+        """
+        VectorWriter.__init__(self, fileName)
+
+        self.file = None
+
+    ##
+    # Public Methods
+    #
+
+    def open(self, startFrame=1, endFrame=1):
+        """Do some initialization operations.
+        """
+        VectorWriter.open(self, startFrame, endFrame)
+
+        self.file = open(self.outputFileName, "w")
+
+        self._printHeader()
+
+    def close(self):
+        """Do some finalization operation.
+        """
+        self._printFooter()
+
+        if self.file:
+            self.file.close()
+
+        # remember to call the close method of the parent as last
+        VectorWriter.close(self)
+
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False,
+            showHiddenEdges=False):
+        """Convert the scene representation to SVG.
+        """
+
+        Objects = scene.objects
+
+        context = scene.getRenderingContext()
+        framenumber = context.currentFrame()
+
+        if self.animation:
+            framestyle = "display:none"
+        else:
+            framestyle = "display:block"
+
+        # Assign an id to this group so we can set properties on it using DOM
+        self.file.write("<g id=\"frame%d\" style=\"%s\">\n" %
+                (framenumber, framestyle))
+
+        for obj in Objects:
+
+            if obj.getType() != 'Mesh':
+                continue
+
+            self.file.write("<g id=\"%s\">\n" % obj.getName())
+
+            mesh = obj.getData(mesh=1)
+
+            if doPrintPolygons:
+                self._printPolygons(mesh)
+
+            if doPrintEdges:
+                self._printEdges(mesh, showHiddenEdges)
+
+            self.file.write("</g>\n")
+
+        self.file.write("</g>\n")
+
+    ##
+    # Private Methods
+    #
+
+    def _calcCanvasCoord(self, v):
+        """Convert vertex in scene coordinates to canvas coordinates.
+        """
+
+        pt = Vector([0, 0, 0])
+
+        mW = float(self.canvasSize[0]) / 2.0
+        mH = float(self.canvasSize[1]) / 2.0
+
+        # rescale to canvas size
+        pt[0] = v.co[0] * mW + mW
+        pt[1] = v.co[1] * mH + mH
+        pt[2] = v.co[2]
+
+        # For now we want (0,0) in the top-left corner of the canvas.
+        # Mirror and translate along y
+        pt[1] *= -1
+        pt[1] += self.canvasSize[1]
+
+        return pt
+
+    def _printHeader(self):
+        """Print SVG header."""
+
+        self.file.write("<?xml version=\"1.0\"?>\n")
+        self.file.write("<!DOCTYPE svg PUBLIC \"-//W3C//DTD SVG 1.0//EN\"\n")
+        self.file.write("\t\"http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd\">\n")
+        self.file.write("<svg version=\"1.0\"\n")
+        self.file.write("\txmlns=\"http://www.w3.org/2000/svg\"\n")
+        self.file.write("\twidth=\"%d\" height=\"%d\">\n\n" %
+                self.canvasSize)
+
+        if self.animation:
+            delay = 1000 / self.fps
+
+            self.file.write("""\n<script type="text/javascript"><![CDATA[
+            globalStartFrame=%d;
+            globalEndFrame=%d;
+
+            timerID = setInterval("NextFrame()", %d);
+            globalFrameCounter=%d;
+            \n""" % (self.startFrame, self.endFrame, delay, self.startFrame))
+
+            self.file.write("""\n
+            function NextFrame()
+            {
+              currentElement  = document.getElementById('frame'+globalFrameCounter)
+              previousElement = document.getElementById('frame'+(globalFrameCounter-1))
+
+              if (!currentElement)
+              {
+                return;
+              }
+
+              if (globalFrameCounter > globalEndFrame)
+              {
+                clearInterval(timerID)
+              }
+              else
+              {
+                if(previousElement)
+                {
+                    previousElement.style.display="none";
+                }
+                currentElement.style.display="block";
+                globalFrameCounter++;
+              }
+            }
+            \n]]></script>\n
+            \n""")
+
+    def _printFooter(self):
+        """Print the SVG footer."""
+
+        self.file.write("\n</svg>\n")
+
+    def _printPolygons(self, mesh):
+        """Print the selected (visible) polygons.
+        """
+
+        if len(mesh.faces) == 0:
+            return
+
+        self.file.write("<g>\n")
+
+        for face in mesh.faces:
+            if not face.sel:
+                continue
+
+            self.file.write("<path d=\"")
+
+            #p = self._calcCanvasCoord(face.verts[0])
+            p = self._calcCanvasCoord(face.v[0])
+            self.file.write("M %g,%g L " % (p[0], p[1]))
+
+            for v in face.v[1:]:
+                p = self._calcCanvasCoord(v)
+                self.file.write("%g,%g " % (p[0], p[1]))
+
+            # get rid of the last blank space, just cosmetics here.
+            self.file.seek(-1, 1)
+            self.file.write(" z\"\n")
+
+            # take as face color the first vertex color
+            if face.col:
+                fcol = face.col[0]
+                color = [fcol.r, fcol.g, fcol.b, fcol.a]
+            else:
+                color = [255, 255, 255, 255]
+
+            # Convert the color to the #RRGGBB form
+            str_col = "#%02X%02X%02X" % (color[0], color[1], color[2])
+
+            # Handle transparent polygons
+            opacity_string = ""
+            if color[3] != 255:
+                opacity = float(color[3]) / 255.0
+                opacity_string = " fill-opacity: %g; stroke-opacity: %g; opacity: 1;" % (opacity, opacity)
+                #opacity_string = "opacity: %g;" % (opacity)
+
+            self.file.write("\tstyle=\"fill:" + str_col + ";")
+            self.file.write(opacity_string)
+
+            # use the stroke property to alleviate the "adjacent edges" problem,
+            # we simulate polygon expansion using borders,
+            # see http://www.antigrain.com/svg/index.html for more info
+            stroke_width = 1.0
+
+            # EXPANSION TRICK is not that useful where there is transparency
+            if config.polygons['EXPANSION_TRICK'] and color[3] == 255:
+                # str_col = "#000000" # For debug
+                self.file.write(" stroke:%s;\n" % str_col)
+                self.file.write(" stroke-width:" + str(stroke_width) + ";\n")
+                self.file.write(" stroke-linecap:round;stroke-linejoin:round")
+
+            self.file.write("\"/>\n")
+
+        self.file.write("</g>\n")
+
+    def _printEdges(self, mesh, showHiddenEdges=False):
+        """Print the wireframe using mesh edges.
+        """
+
+        stroke_width = config.edges['WIDTH']
+        stroke_col = config.edges['COLOR']
+
+        self.file.write("<g>\n")
+
+        for e in mesh.edges:
+
+            hidden_stroke_style = ""
+
+            if e.sel == 0:
+                if showHiddenEdges == False:
+                    continue
+                else:
+                    hidden_stroke_style = ";\n stroke-dasharray:3, 3"
+
+            p1 = self._calcCanvasCoord(e.v1)
+            p2 = self._calcCanvasCoord(e.v2)
+
+            self.file.write("<line x1=\"%g\" y1=\"%g\" x2=\"%g\" y2=\"%g\"\n"
+                    % (p1[0], p1[1], p2[0], p2[1]))
+            self.file.write(" style=\"stroke:rgb(" + str(stroke_col[0]) + "," + str(stroke_col[1]) + "," + str(stroke_col[2]) + ");")
+            self.file.write(" stroke-width:" + str(stroke_width) + ";\n")
+            self.file.write(" stroke-linecap:round;stroke-linejoin:round")
+            self.file.write(hidden_stroke_style)
+            self.file.write("\"/>\n")
+
+        self.file.write("</g>\n")
+
+
+## SWF Writer
+
+try:
+    from ming import *
+    SWFSupported = True
+except:
+    SWFSupported = False
+
+
+class SWFVectorWriter(VectorWriter):
+    """A concrete class for writing SWF output.
+    """
+
+    def __init__(self, fileName):
+        """Simply call the parent Contructor.
+        """
+        VectorWriter.__init__(self, fileName)
+
+        self.movie = None
+        self.sprite = None
+
+    ##
+    # Public Methods
+    #
+
+    def open(self, startFrame=1, endFrame=1):
+        """Do some initialization operations.
+        """
+        VectorWriter.open(self, startFrame, endFrame)
+        self.movie = SWFMovie()
+        self.movie.setDimension(self.canvasSize[0], self.canvasSize[1])
+        if self.animation:
+            self.movie.setRate(self.fps)
+            numframes = endFrame - startFrame + 1
+            self.movie.setFrames(numframes)
+
+    def close(self):
+        """Do some finalization operation.
+        """
+        self.movie.save(self.outputFileName)
+
+        # remember to call the close method of the parent
+        VectorWriter.close(self)
+
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False,
+            showHiddenEdges=False):
+        """Convert the scene representation to SVG.
+        """
+        context = scene.getRenderingContext()
+        framenumber = context.currentFrame()
+
+        Objects = scene.objects
+
+        if self.sprite:
+            self.movie.remove(self.sprite)
+
+        sprite = SWFSprite()
+
+        for obj in Objects:
+
+            if(obj.getType() != 'Mesh'):
+                continue
+
+            mesh = obj.getData(mesh=1)
+
+            if doPrintPolygons:
+                self._printPolygons(mesh, sprite)
+
+            if doPrintEdges:
+                self._printEdges(mesh, sprite, showHiddenEdges)
+
+        sprite.nextFrame()
+        i = self.movie.add(sprite)
+        # Remove the instance the next time
+        self.sprite = i
+        if self.animation:
+            self.movie.nextFrame()
+
+    ##
+    # Private Methods
+    #
+
+    def _calcCanvasCoord(self, v):
+        """Convert vertex in scene coordinates to canvas coordinates.
+        """
+
+        pt = Vector([0, 0, 0])
+
+        mW = float(self.canvasSize[0]) / 2.0
+        mH = float(self.canvasSize[1]) / 2.0
+
+        # rescale to canvas size
+        pt[0] = v.co[0] * mW + mW
+        pt[1] = v.co[1] * mH + mH
+        pt[2] = v.co[2]
+
+        # For now we want (0,0) in the top-left corner of the canvas.
+        # Mirror and translate along y
+        pt[1] *= -1
+        pt[1] += self.canvasSize[1]
+
+        return pt
+
+    def _printPolygons(self, mesh, sprite):
+        """Print the selected (visible) polygons.
+        """
+
+        if len(mesh.faces) == 0:
+            return
+
+        for face in mesh.faces:
+            if not face.sel:
+                continue
+
+            if face.col:
+                fcol = face.col[0]
+                color = [fcol.r, fcol.g, fcol.b, fcol.a]
+            else:
+                color = [255, 255, 255, 255]
+
+            s = SWFShape()
+            f = s.addFill(color[0], color[1], color[2], color[3])
+            s.setRightFill(f)
+
+            # The starting point of the shape
+            p0 = self._calcCanvasCoord(face.verts[0])
+            s.movePenTo(p0[0], p0[1])
+
+            for v in face.verts[1:]:
+                p = self._calcCanvasCoord(v)
+                s.drawLineTo(p[0], p[1])
+
+            # Closing the shape
+            s.drawLineTo(p0[0], p0[1])
+
+            s.end()
+            sprite.add(s)
+
+    def _printEdges(self, mesh, sprite, showHiddenEdges=False):
+        """Print the wireframe using mesh edges.
+        """
+
+        stroke_width = config.edges['WIDTH']
+        stroke_col = config.edges['COLOR']
+
+        s = SWFShape()
+
+        for e in mesh.edges:
+
+            # Next, we set the line width and color for our shape.
+            s.setLine(stroke_width, stroke_col[0], stroke_col[1], stroke_col[2],
+            255)
+
+            if e.sel == 0:
+                if showHiddenEdges == False:
+                    continue
+                else:
+                    # SWF does not support dashed lines natively, so -for now-
+                    # draw hidden lines thinner and half-trasparent
+                    s.setLine(stroke_width / 2, stroke_col[0], stroke_col[1],
+                            stroke_col[2], 128)
+
+            p1 = self._calcCanvasCoord(e.v1)
+            p2 = self._calcCanvasCoord(e.v2)
+
+            s.movePenTo(p1[0], p1[1])
+            s.drawLineTo(p2[0], p2[1])
+
+        s.end()
+        sprite.add(s)
+
+
+## PDF Writer
+
+try:
+    from reportlab.pdfgen import canvas
+    PDFSupported = True
+except:
+    PDFSupported = False
+
+
+class PDFVectorWriter(VectorWriter):
+    """A concrete class for writing PDF output.
+    """
+
+    def __init__(self, fileName):
+        """Simply call the parent Contructor.
+        """
+        VectorWriter.__init__(self, fileName)
+
+        self.canvas = None
+
+    ##
+    # Public Methods
+    #
+
+    def open(self, startFrame=1, endFrame=1):
+        """Do some initialization operations.
+        """
+        VectorWriter.open(self, startFrame, endFrame)
+        size = (self.canvasSize[0], self.canvasSize[1])
+        self.canvas = canvas.Canvas(self.outputFileName, pagesize=size, bottomup=0)
+
+    def close(self):
+        """Do some finalization operation.
+        """
+        self.canvas.save()
+
+        # remember to call the close method of the parent
+        VectorWriter.close(self)
+
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False,
+            showHiddenEdges=False):
+        """Convert the scene representation to SVG.
+        """
+        context = scene.getRenderingContext()
+        framenumber = context.currentFrame()
+
+        Objects = scene.objects
+
+        for obj in Objects:
+
+            if(obj.getType() != 'Mesh'):
+                continue
+
+            mesh = obj.getData(mesh=1)
+
+            if doPrintPolygons:
+                self._printPolygons(mesh)
+
+            if doPrintEdges:
+                self._printEdges(mesh, showHiddenEdges)
+
+        self.canvas.showPage()
+
+    ##
+    # Private Methods
+    #
+
+    def _calcCanvasCoord(self, v):
+        """Convert vertex in scene coordinates to canvas coordinates.
+        """
+
+        pt = Vector([0, 0, 0])
+
+        mW = float(self.canvasSize[0]) / 2.0
+        mH = float(self.canvasSize[1]) / 2.0
+
+        # rescale to canvas size
+        pt[0] = v.co[0] * mW + mW
+        pt[1] = v.co[1] * mH + mH
+        pt[2] = v.co[2]
+
+        # For now we want (0,0) in the top-left corner of the canvas.
+        # Mirror and translate along y
+        pt[1] *= -1
+        pt[1] += self.canvasSize[1]
+
+        return pt
+
+    def _printPolygons(self, mesh):
+        """Print the selected (visible) polygons.
+        """
+
+        if len(mesh.faces) == 0:
+            return
+
+        for face in mesh.faces:
+            if not face.sel:
+                continue
+
+            if face.col:
+                fcol = face.col[0]
+                color = [fcol.r / 255.0, fcol.g / 255.0, fcol.b / 255.0,
+                        fcol.a / 255.0]
+            else:
+                color = [1, 1, 1, 1]
+
+            self.canvas.setFillColorRGB(color[0], color[1], color[2])
+            # For debug
+            self.canvas.setStrokeColorRGB(0, 0, 0)
+
+            path = self.canvas.beginPath()
+
+            # The starting point of the path
+            p0 = self._calcCanvasCoord(face.verts[0])
+            path.moveTo(p0[0], p0[1])
+
+            for v in face.verts[1:]:
+                p = self._calcCanvasCoord(v)
+                path.lineTo(p[0], p[1])
+
+            # Closing the shape
+            path.close()
+
+            self.canvas.drawPath(path, stroke=0, fill=1)
+
+    def _printEdges(self, mesh, showHiddenEdges=False):
+        """Print the wireframe using mesh edges.
+        """
+
+        stroke_width = config.edges['WIDTH']
+        stroke_col = config.edges['COLOR']
+
+        self.canvas.setLineCap(1)
+        self.canvas.setLineJoin(1)
+        self.canvas.setLineWidth(stroke_width)
+        self.canvas.setStrokeColorRGB(stroke_col[0] / 255.0, stroke_col[1] / 255.0,
+            stroke_col[2] / 255)
+
+        for e in mesh.edges:
+
+            self.canvas.setLineWidth(stroke_width)
+
+            if e.sel == 0:
+                if showHiddenEdges == False:
+                    continue
+                else:
+                    # PDF does not support dashed lines natively, so -for now-
+                    # draw hidden lines thinner
+                    self.canvas.setLineWidth(stroke_width / 2.0)
+
+            p1 = self._calcCanvasCoord(e.v1)
+            p2 = self._calcCanvasCoord(e.v2)
+
+            self.canvas.line(p1[0], p1[1], p2[0], p2[1])
+
+# ---------------------------------------------------------------------
+#
+## Rendering Classes
+#
+# ---------------------------------------------------------------------
+
+# A dictionary to collect different shading style methods
+shadingStyles = dict()
+shadingStyles['FLAT'] = None
+shadingStyles['TOON'] = None
+
+# A dictionary to collect different edge style methods
+edgeStyles = dict()
+edgeStyles['MESH'] = MeshUtils.isMeshEdge
+edgeStyles['SILHOUETTE'] = MeshUtils.isSilhouetteEdge
+
+# A dictionary to collect the supported output formats
+outputWriters = dict()
+outputWriters['SVG'] = SVGVectorWriter
+if SWFSupported:
+    outputWriters['SWF'] = SWFVectorWriter
+if PDFSupported:
+    outputWriters['PDF'] = PDFVectorWriter
+
+
+class Renderer:
+    """Render a scene viewed from the active camera.
+
+    This class is responsible of the rendering process, transformation and
+    projection of the objects in the scene are invoked by the renderer.
+
+    The rendering is done using the active camera for the current scene.
+    """
+
+    def __init__(self):
+        """Make the rendering process only for the current scene by default.
+
+        We will work on a copy of the scene, to be sure that the current scene do
+        not get modified in any way.
+        """
+
+        # Render the current Scene, this should be a READ-ONLY property
+        self._SCENE = Scene.GetCurrent()
+
+        # Use the aspect ratio of the scene rendering context
+        context = self._SCENE.getRenderingContext()
+
+        aspect_ratio = float(context.imageSizeX()) / float(context.imageSizeY())
+        self.canvasRatio = (float(context.aspectRatioX()) * aspect_ratio,
+                            float(context.aspectRatioY())
+                            )
+
+        # Render from the currently active camera
+        #self.cameraObj = self._SCENE.objects.camera
+
+        self.lights = []
+
+    ##
+    # Public Methods
+    #
+
+    def doRendering(self, outputWriter, animation=False):
+        """Render picture or animation and write it out.
+
+        The parameters are:
+            - a Vector writer object that will be used to output the result.
+            - a flag to tell if we want to render an animation or only the
+              current frame.
+        """
+
+        context = self._SCENE.getRenderingContext()
+        origCurrentFrame = context.currentFrame()
+
+        # Handle the animation case
+        if not animation:
+            startFrame = origCurrentFrame
+            endFrame = startFrame
+            outputWriter.open()
+        else:
+            startFrame = context.startFrame()
+            endFrame = context.endFrame()
+            outputWriter.open(startFrame, endFrame)
+
+        # Do the rendering process frame by frame
+        print "Start Rendering of %d frames" % (endFrame - startFrame + 1)
+        for f in xrange(startFrame, endFrame + 1):
+            print "\n\nFrame: %d" % f
+
+            # FIXME To get the correct camera position we have to use +1 here.
+            # Is there a bug somewhere in the Scene module?
+            context.currentFrame(f + 1)
+            self.cameraObj = self._SCENE.objects.camera
+
+            # Use some temporary workspace, a full copy of the scene
+            inputScene = self._SCENE.copy(2)
+
+            # To get the objects at this frame remove the +1 ...
+            ctx = inputScene.getRenderingContext()
+            ctx.currentFrame(f)
+
+            # Get a projector for this camera.
+            # NOTE: the projector wants object in world coordinates,
+            # so we should remember to apply modelview transformations
+            # _before_ we do projection transformations.
+            self.proj = Projector(self.cameraObj, self.canvasRatio)
+
+            try:
+                renderedScene = self.doRenderScene(inputScene)
+            except:
+                print "There was an error! Aborting."
+                import traceback
+                print traceback.print_exc()
+
+                self._SCENE.makeCurrent()
+                Scene.Unlink(inputScene)
+                del inputScene
+                return
+
+            outputWriter.printCanvas(renderedScene,
+                    doPrintPolygons=config.polygons['SHOW'],
+                    doPrintEdges=config.edges['SHOW'],
+                    showHiddenEdges=config.edges['SHOW_HIDDEN'])
+
+            # delete the rendered scene
+            self._SCENE.makeCurrent()
+            Scene.Unlink(renderedScene)
+            del renderedScene
+
+        outputWriter.close()
+        print "Done!"
+        context.currentFrame(origCurrentFrame)
+
+    def doRenderScene(self, workScene):
+        """Control the rendering process.
+
+        Here we control the entire rendering process invoking the operation
+        needed to transform and project the 3D scene in two dimensions.
+        """
+
+        # global processing of the scene
+
+        self._filterHiddenObjects(workScene)
+
+        self._buildLightSetup(workScene)
+
+        self._doSceneClipping(workScene)
+
+        self._doConvertGeometricObjsToMesh(workScene)
+
+        if config.output['JOIN_OBJECTS']:
+            self._joinMeshObjectsInScene(workScene)
+
+        self._doSceneDepthSorting(workScene)
+
+        # Per object activities
+
+        Objects = workScene.objects
+
+        print "Total Objects: %d" % len(Objects)
+        for i, obj in enumerate(Objects):
+            print "\n\n-------"
+            print "Rendering Object: %d" % i
+
+            if obj.getType() != 'Mesh':
+                print "Only Mesh supported! - Skipping type:", obj.getType()
+                continue
+
+            print "Rendering: ", obj.getName()
+
+            mesh = obj.getData(mesh=1)
+
+            self._doModelingTransformation(mesh, obj.matrix)
+
+            self._doBackFaceCulling(mesh)
+
+            # When doing HSR with NEWELL we may want to flip all normals
+            # toward the viewer
+            if config.polygons['HSR'] == "NEWELL":
+                for f in mesh.faces:
+                    f.sel = 1 - f.sel
+                mesh.flipNormals()
+                for f in mesh.faces:
+                    f.sel = 1
+
+            self._doLighting(mesh)
+
+            # Do "projection" now so we perform further processing
+            # in Normalized View Coordinates
+            self._doProjection(mesh, self.proj)
+
+            self._doViewFrustumClipping(mesh)
+
+            self._doHiddenSurfaceRemoval(mesh)
+
+            self._doEdgesStyle(mesh, edgeStyles[config.edges['STYLE']])
+
+            # Update the object data, important! :)
+            mesh.update()
+
+        return workScene
+
+    ##
+    # Private Methods
+    #
+
+    # Utility methods
+
+    def _getObjPosition(self, obj):
+        """Return the obj position in World coordinates.
+        """
+        return obj.matrix.translationPart()
+
+    def _cameraViewVector(self):
+        """Get the View Direction form the camera matrix.
+        """
+        return Vector(self.cameraObj.matrix[2]).resize3D()
+
+    # Faces methods
+
+    def _isFaceVisible(self, face):
+        """Determine if a face of an object is visible from the current camera.
+
+        The view vector is calculated from the camera location and one of the
+        vertices of the face (expressed in World coordinates, after applying
+        modelview transformations).
+
+        After those transformations we determine if a face is visible by
+        computing the angle between the face normal and the view vector, this
+        angle has to be between -90 and 90 degrees for the face to be visible.
+        This corresponds somehow to the dot product between the two, if it
+        results > 0 then the face is visible.
+
+        There is no need to normalize those vectors since we are only interested in
+        the sign of the cross product and not in the product value.
+
+        NOTE: here we assume the face vertices are in WorldCoordinates, so
+        please transform the object _before_ doing the test.
+        """
+
+        normal = Vector(face.no)
+        camPos = self._getObjPosition(self.cameraObj)
+        view_vect = None
+
+        # View Vector in orthographics projections is the view Direction of
+        # the camera
+        if self.cameraObj.data.getType() == 1:
+            view_vect = self._cameraViewVector()
+
+        # View vector in perspective projections can be considered as
+        # the difference between the camera position and one point of
+        # the face, we choose the farthest point from the camera.
+        if self.cameraObj.data.getType() == 0:
+            vv = max([((camPos - Vector(v.co)).length, (camPos - Vector(v.co))) for v in face])
+            view_vect = vv[1]
+
+        # if d > 0 the face is visible from the camera
+        d = view_vect * normal
+
+        if d > 0:
+            return True
+        else:
+            return False
+
+    # Scene methods
+
+    def _filterHiddenObjects(self, scene):
+        """Discard object that are on hidden layers in the scene.
+        """
+
+        Objects = scene.objects
+
+        visible_obj_list = [obj for obj in Objects if
+                set(obj.layers).intersection(set(scene.getLayers()))]
+
+        for o in Objects:
+            if o not in visible_obj_list:
+                scene.objects.unlink(o)
+
+        scene.update()
+
+    def _buildLightSetup(self, scene):
+        # Get the list of lighting sources
+        obj_lst = scene.objects
+        self.lights = [o for o in obj_lst if o.getType() == 'Lamp']
+
+        # When there are no lights we use a default lighting source
+        # that have the same position of the camera
+        if len(self.lights) == 0:
+            l = Lamp.New('Lamp')
+            lobj = Object.New('Lamp')
+            lobj.loc = self.cameraObj.loc
+            lobj.link(l)
+            self.lights.append(lobj)
+
+    def _doSceneClipping(self, scene):
+        """Clip whole objects against the View Frustum.
+
+        For now clip away only objects according to their center position.
+        """
+
+        cam_pos = self._getObjPosition(self.cameraObj)
+        view_vect = self._cameraViewVector()
+
+        near = self.cameraObj.data.clipStart
+        far = self.cameraObj.data.clipEnd
+
+        aspect = float(self.canvasRatio[0]) / float(self.canvasRatio[1])
+        fovy = atan(0.5 / aspect / (self.cameraObj.data.lens / 32))
+        fovy = fovy * 360.0 / pi
+
+        Objects = scene.objects
+
+        for o in Objects:
+            if o.getType() != 'Mesh':
+                continue
+
+            """
+            obj_vect = Vector(cam_pos) - self._getObjPosition(o)
+
+            d = obj_vect*view_vect
+            theta = AngleBetweenVecs(obj_vect, view_vect)
+
+            # if the object is outside the view frustum, clip it away
+            if (d < near) or (d > far) or (theta > fovy):
+                scene.objects.unlink(o)
+            """
+
+            # Use the object bounding box
+            # (whose points are already in WorldSpace Coordinate)
+
+            bb = o.getBoundBox()
+
+            points_outside = 0
+            for p in bb:
+                p_vect = Vector(cam_pos) - Vector(p)
+
+                d = p_vect * view_vect
+                theta = AngleBetweenVecs(p_vect, view_vect)
+
+                # Is this point outside the view frustum?
+                if (d < near) or (d > far) or (theta > fovy):
+                    points_outside += 1
+
+            # If the bb is all outside the view frustum we clip the whole
+            # object away
+            if points_outside == len(bb):
+                scene.objects.unlink(o)
+
+    def _doConvertGeometricObjsToMesh(self, scene):
+        """Convert all "geometric" objects to mesh ones.
+        """
+        geometricObjTypes = ['Mesh', 'Surf', 'Curve', 'Text']
+        #geometricObjTypes = ['Mesh', 'Surf', 'Curve']
+
+        Objects = scene.objects
+
+        objList = [o for o in Objects if o.getType() in geometricObjTypes]
+        for obj in objList:
+            old_obj = obj
+            obj = self._convertToRawMeshObj(obj)
+            scene.objects.link(obj)
+            scene.objects.unlink(old_obj)
+
+            # XXX Workaround for Text and Curve which have some normals
+            # inverted when they are converted to Mesh, REMOVE that when
+            # blender will fix that!!
+            if old_obj.getType() in ['Curve', 'Text']:
+                me = obj.getData(mesh=1)
+
+                for f in me.faces:
+                    f.sel = 1
+                for v in me.verts:
+                    v.sel = 1
+
+                me.remDoubles(0)
+                me.triangleToQuad()
+                me.recalcNormals()
+                me.update()
+
+    def _doSceneDepthSorting(self, scene):
+        """Sort objects in the scene.
+
+        The object sorting is done accordingly to the object centers.
+        """
+
+        c = self._getObjPosition(self.cameraObj)
+
+        by_obj_center_pos = (lambda o1, o2:
+                (o1.getType() == 'Mesh' and o2.getType() == 'Mesh') and
+                cmp((self._getObjPosition(o1) - Vector(c)).length,
+                    (self._getObjPosition(o2) - Vector(c)).length)
+            )
+
+        # Implement sorting by bounding box, the object with the bb
+        # nearest to the camera should be drawn as last.
+        by_nearest_bbox_point = (lambda o1, o2:
+                (o1.getType() == 'Mesh' and o2.getType() == 'Mesh') and
+                cmp(min([(Vector(p) - Vector(c)).length for p in o1.getBoundBox()]),
+                    min([(Vector(p) - Vector(c)).length for p in o2.getBoundBox()])
+                )
+            )
+
+        Objects = list(scene.objects)
+
+        #Objects.sort(by_obj_center_pos)
+        Objects.sort(by_nearest_bbox_point)
+
+        # update the scene
+        for o in Objects:
+            scene.objects.unlink(o)
+            scene.objects.link(o)
+
+    def _joinMeshObjectsInScene(self, scene):
+        """Merge all the Mesh Objects in a scene into a single Mesh Object.
+        """
+
+        oList = [o for o in scene.objects if o.getType() == 'Mesh']
+
+        # FIXME: Object.join() do not work if the list contains 1 object
+        if len(oList) == 1:
+            return
+
+        mesh = Mesh.New('BigOne')
+        bigObj = Object.New('Mesh', 'BigOne')
+        bigObj.link(mesh)
+
+        scene.objects.link(bigObj)
+
+        try:
+            bigObj.join(oList)
+        except RuntimeError:
+            print "\nWarning! - Can't Join Objects\n"
+            scene.objects.unlink(bigObj)
+            return
+        except TypeError:
+            print "Objects Type error?"
+
+        for o in oList:
+            scene.objects.unlink(o)
+
+        scene.update()
+
+    # Per object/mesh methods
+
+    def _convertToRawMeshObj(self, object):
+        """Convert geometry based object to a mesh object.
+        """
+        me = Mesh.New('RawMesh_' + object.name)
+        me.getFromObject(object.name)
+
+        newObject = Object.New('Mesh', 'RawMesh_' + object.name)
+        newObject.link(me)
+
+        # If the object has no materials set a default material
+        if not me.materials:
+            me.materials = [Material.New()]
+            #for f in me.faces: f.mat = 0
+
+        newObject.setMatrix(object.getMatrix())
+
+        return newObject
+
+    def _doModelingTransformation(self, mesh, matrix):
+        """Transform object coordinates to world coordinates.
+
+        This step is done simply applying to the object its tranformation
+        matrix and recalculating its normals.
+        """
+        # XXX FIXME: blender do not transform normals in the right way when
+        # there are negative scale values
+        if matrix[0][0] < 0 or matrix[1][1] < 0 or matrix[2][2] < 0:
+            print "WARNING: Negative scales, expect incorrect results!"
+
+        mesh.transform(matrix, True)
+
+    def _doBackFaceCulling(self, mesh):
+        """Simple Backface Culling routine.
+
+        At this level we simply do a visibility test face by face and then
+        select the vertices belonging to visible faces.
+        """
+
+        # Select all vertices, so edges can be displayed even if there are no
+        # faces
+        for v in mesh.verts:
+            v.sel = 1
+
+        Mesh.Mode(Mesh.SelectModes['FACE'])
+        # Loop on faces
+        for f in mesh.faces:
+            f.sel = 0
+            if self._isFaceVisible(f):
+                f.sel = 1
+
+    def _doLighting(self, mesh):
+        """Apply an Illumination and shading model to the object.
+
+        The model used is the Phong one, it may be inefficient,
+        but I'm just learning about rendering and starting from Phong seemed
+        the most natural way.
+        """
+
+        # If the mesh has vertex colors already, use them,
+        # otherwise turn them on and do some calculations
+        if mesh.vertexColors:
+            return
+        mesh.vertexColors = 1
+
+        materials = mesh.materials
+
+        camPos = self._getObjPosition(self.cameraObj)
+
+        # We do per-face color calculation (FLAT Shading), we can easily turn
+        # to a per-vertex calculation if we want to implement some shading
+        # technique. For an example see:
+        # http://www.miralab.unige.ch/papers/368.pdf
+        for f in mesh.faces:
+            if not f.sel:
+                continue
+
+            mat = None
+            if materials:
+                mat = materials[f.mat]
+
+            # A new default material
+            if mat == None:
+                mat = Material.New('defMat')
+
+            # Check if it is a shadeless material
+            elif mat.getMode() & Material.Modes['SHADELESS']:
+                I = mat.getRGBCol()
+                # Convert to a value between 0 and 255
+                tmp_col = [int(c * 255.0) for c in I]
+
+                for c in f.col:
+                    c.r = tmp_col[0]
+                    c.g = tmp_col[1]
+                    c.b = tmp_col[2]
+                    #c.a = tmp_col[3]
+
+                continue
+
+            # do vertex color calculation
+
+            TotDiffSpec = Vector([0.0, 0.0, 0.0])
+
+            for l in self.lights:
+                light_obj = l
+                light_pos = self._getObjPosition(l)
+                light = light_obj.getData()
+
+                L = Vector(light_pos).normalize()
+
+                V = (Vector(camPos) - Vector(f.cent)).normalize()
+
+                N = Vector(f.no).normalize()
+
+                if config.polygons['SHADING'] == 'TOON':
+                    NL = ShadingUtils.toonShading(N * L)
+                else:
+                    NL = (N * L)
+
+                # Should we use NL instead of (N*L) here?
+                R = 2 * (N * L) * N - L
+
+                Ip = light.getEnergy()
+
+                # Diffuse co-efficient
+                kd = mat.getRef() * Vector(mat.getRGBCol())
+                for i in [0, 1, 2]:
+                    kd[i] *= light.col[i]
+
+                Idiff = Ip * kd * max(0, NL)
+
+                # Specular component
+                ks = mat.getSpec() * Vector(mat.getSpecCol())
+                ns = mat.getHardness()
+                Ispec = Ip * ks * pow(max(0, (V * R)), ns)
+
+                TotDiffSpec += (Idiff + Ispec)
+
+            # Ambient component
+            Iamb = Vector(Blender.World.Get()[0].getAmb())
+            ka = mat.getAmb()
+
+            # Emissive component (convert to a triplet)
+            ki = Vector([mat.getEmit()] * 3)
+
+            #I = ki + Iamb + (Idiff + Ispec)
+            I = ki + (ka * Iamb) + TotDiffSpec
+
+            # Set Alpha component
+            I = list(I)
+            I.append(mat.getAlpha())
+
+            # Clamp I values between 0 and 1
+            I = [min(c, 1) for c in I]
+            I = [max(0, c) for c in I]
+
+            # Convert to a value between 0 and 255
+            tmp_col = [int(c * 255.0) for c in I]
+
+            for c in f.col:
+                c.r = tmp_col[0]
+                c.g = tmp_col[1]
+                c.b = tmp_col[2]
+                c.a = tmp_col[3]
+
+    def _doProjection(self, mesh, projector):
+        """Apply Viewing and Projection tranformations.
+        """
+
+        for v in mesh.verts:
+            p = projector.doProjection(v.co[:])
+            v.co[0] = p[0]
+            v.co[1] = p[1]
+            v.co[2] = p[2]
+
+        #mesh.recalcNormals()
+        #mesh.update()
+
+        # We could reeset Camera matrix, since now
+        # we are in Normalized Viewing Coordinates,
+        # but doung that would affect World Coordinate
+        # processing for other objects
+
+        #self.cameraObj.data.type = 1
+        #self.cameraObj.data.scale = 2.0
+        #m = Matrix().identity()
+        #self.cameraObj.setMatrix(m)
+
+    def _doViewFrustumClipping(self, mesh):
+        """Clip faces against the View Frustum.
+        """
+
+        # The Canonical View Volume, 8 vertices, and 6 faces,
+        # We consider its face normals pointing outside
+
+        v1 = NMesh.Vert(1, 1, -1)
+        v2 = NMesh.Vert(1, -1, -1)
+        v3 = NMesh.Vert(-1, -1, -1)
+        v4 = NMesh.Vert(-1, 1, -1)
+        v5 = NMesh.Vert(1, 1, 1)
+        v6 = NMesh.Vert(1, -1, 1)
+        v7 = NMesh.Vert(-1, -1, 1)
+        v8 = NMesh.Vert(-1, 1, 1)
+
+        cvv = []
+        f1 = NMesh.Face([v1, v4, v3, v2])
+        cvv.append(f1)
+        f2 = NMesh.Face([v5, v6, v7, v8])
+        cvv.append(f2)
+        f3 = NMesh.Face([v1, v2, v6, v5])
+        cvv.append(f3)
+        f4 = NMesh.Face([v2, v3, v7, v6])
+        cvv.append(f4)
+        f5 = NMesh.Face([v3, v4, v8, v7])
+        cvv.append(f5)
+        f6 = NMesh.Face([v4, v1, v5, v8])
+        cvv.append(f6)
+
+        nmesh = NMesh.GetRaw(mesh.name)
+        clippedfaces = nmesh.faces[:]
+        facelist = clippedfaces[:]
+
+        for clipface in cvv:
+
+            clippedfaces = []
+
+            for f in facelist:
+
+                #newfaces = HSR.splitOn(clipface, f, return_positive_faces=False)
+                newfaces = None
+
+                if not newfaces:
+                    # Check if the face is all outside the view frustum
+                    # TODO: Do this test before, it is more efficient
+                    points_outside = 0
+                    for v in f:
+                        if abs(v[0]) > (1 - EPS) or abs(v[1]) > (1 - EPS) or abs(v[2]) > (1 - EPS):
+                            points_outside += 1
+
+                    if points_outside != len(f):
+                        clippedfaces.append(f)
+                else:
+                    for nf in newfaces:
+                        for v in nf:
+                            nmesh.verts.append(v)
+
+                        nf.mat = f.mat
+                        nf.sel = f.sel
+                        nf.col = [f.col[0]] * len(nf.v)
+
+                        clippedfaces.append(nf)
+            facelist = clippedfaces[:]
+
+        nmesh.faces = facelist
+        nmesh.update()
+
+    # HSR routines
+    def __simpleDepthSort(self, mesh):
+        """Sort faces by the furthest vertex.
+
+        This simple mesthod is known also as the painter algorithm, and it
+        solves HSR correctly only for convex meshes.
+        """
+
+        #global progress
+
+        # The sorting requires circa n*log(n) steps
+        n = len(mesh.faces)
+        progress.setActivity("HSR: Painter", n * log(n))
+
+        by_furthest_z = (lambda f1, f2: progress.update() and
+                cmp(max([v.co[2] for v in f1]), max([v.co[2] for v in f2]) + EPS)
+                )
+
+        # FIXME: using NMesh to sort faces. We should avoid that!
+        nmesh = NMesh.GetRaw(mesh.name)
+
+        # remember that _higher_ z values mean further points
+        nmesh.faces.sort(by_furthest_z)
+        nmesh.faces.reverse()
+
+        nmesh.update()
+
+    def __newellDepthSort(self, mesh):
+        """Newell's depth sorting.
+
+        """
+
+        #global progress
+
+        # Find non planar quads and convert them to triangle
+        #for f in mesh.faces:
+        #    f.sel = 0
+        #    if is_nonplanar_quad(f.v):
+        #        print "NON QUAD??"
+        #        f.sel = 1
+
+        # Now reselect all faces
+        for f in mesh.faces:
+            f.sel = 1
+        mesh.quadToTriangle()
+
+        # FIXME: using NMesh to sort faces. We should avoid that!
+        nmesh = NMesh.GetRaw(mesh.name)
+
+        # remember that _higher_ z values mean further points
+        nmesh.faces.sort(by_furthest_z)
+        nmesh.faces.reverse()
+
+        # Begin depth sort tests
+
+        # use the smooth flag to set marked faces
+        for f in nmesh.faces:
+            f.smooth = 0
+
+        facelist = nmesh.faces[:]
+        maplist = []
+
+        # The steps are _at_least_ equal to len(facelist), we do not count the
+        # feces coming out from splitting!!
+        progress.setActivity("HSR: Newell", len(facelist))
+        #progress.setQuiet(True)
+
+        while len(facelist):
+            debug("\n----------------------\n")
+            debug("len(facelits): %d\n" % len(facelist))
+            P = facelist[0]
+
+            pSign = sign(P.normal[2])
+
+            # We can discard faces parallel to the view vector
+            #if P.normal[2] == 0:
+            #    facelist.remove(P)
+            #    continue
+
+            split_done = 0
+            face_marked = 0
+
+            for Q in facelist[1:]:
+
+                debug("P.smooth: " + str(P.smooth) + "\n")
+                debug("Q.smooth: " + str(Q.smooth) + "\n")
+                debug("\n")
+
+                qSign = sign(Q.normal[2])
+                # TODO: check also if Q is parallel??
+
+                # Test 0: We need to test only those Qs whose furthest vertex
+                # is closer to the observer than the closest vertex of P.
+
+                zP = [v.co[2] for v in P.v]
+                zQ = [v.co[2] for v in Q.v]
+                notZOverlap = min(zP) > max(zQ) + EPS
+
+                if notZOverlap:
+                    debug("\nTest 0\n")
+                    debug("NOT Z OVERLAP!\n")
+                    if Q.smooth == 0:
+                        # If Q is not marked then we can safely print P
+                        break
+                    else:
+                        debug("met a marked face\n")
+                        continue
+
+                # Test 1: X extent overlapping
+                xP = [v.co[0] for v in P.v]
+                xQ = [v.co[0] for v in Q.v]
+                #notXOverlap = (max(xP) <= min(xQ)) or (max(xQ) <= min(xP))
+                notXOverlap = min(xQ) >= (max(xP) - EPS) or min(xP) >= (max(xQ) - EPS)
+
+                if notXOverlap:
+                    debug("\nTest 1\n")
+                    debug("NOT X OVERLAP!\n")
+                    continue
+
+                # Test 2: Y extent Overlapping
+                yP = [v.co[1] for v in P.v]
+                yQ = [v.co[1] for v in Q.v]
+                #notYOverlap = max(yP) <= min(yQ) or max(yQ) <= min(yP)
+                notYOverlap = min(yQ) >= (max(yP) - EPS) or min(yP) >= (max(yQ) - EPS)
+
+                if notYOverlap:
+                    debug("\nTest 2\n")
+                    debug("NOT Y OVERLAP!\n")
+                    continue
+
+                # Test 3: P vertices are all behind the plane of Q
+                n = 0
+                for Pi in P:
+                    d = qSign * HSR.Distance(Vector(Pi), Q)
+                    if d <= EPS:
+                        n += 1
+                pVerticesBehindPlaneQ = (n == len(P))
+
+                if pVerticesBehindPlaneQ:
+                    debug("\nTest 3\n")
+                    debug("P BEHIND Q!\n")
+                    continue
+
+                # Test 4: Q vertices in front of the plane of P
+                n = 0
+                for Qi in Q:
+                    d = pSign * HSR.Distance(Vector(Qi), P)
+                    if d >= -EPS:
+                        n += 1
+                qVerticesInFrontPlaneP = (n == len(Q))
+
+                if qVerticesInFrontPlaneP:
+                    debug("\nTest 4\n")
+                    debug("Q IN FRONT OF P!\n")
+                    continue
+
+                # Test 5: Check if projections of polygons effectively overlap,
+                # in previous tests we checked only bounding boxes.
+
+                #if not projectionsOverlap(P, Q):
+                if not (HSR.projectionsOverlap(P, Q) or HSR.projectionsOverlap(Q, P)):
+                    debug("\nTest 5\n")
+                    debug("Projections do not overlap!\n")
+                    continue
+
+                # We still can't say if P obscures Q.
+
+                # But if Q is marked we do a face-split trying to resolve a
+                # difficulty (maybe a visibility cycle).
+                if Q.smooth == 1:
+                    # Split P or Q
+                    debug("Possibly a cycle detected!\n")
+                    debug("Split here!!\n")
+
+                    facelist = HSR.facesplit(P, Q, facelist, nmesh)
+                    split_done = 1
+                    break
+
+                # The question now is: Does Q obscure P?
+
+                # Test 3bis: Q vertices are all behind the plane of P
+                n = 0
+                for Qi in Q:
+                    d = pSign * HSR.Distance(Vector(Qi), P)
+                    if d <= EPS:
+                        n += 1
+                qVerticesBehindPlaneP = (n == len(Q))
+
+                if qVerticesBehindPlaneP:
+                    debug("\nTest 3bis\n")
+                    debug("Q BEHIND P!\n")
+
+                # Test 4bis: P vertices in front of the plane of Q
+                n = 0
+                for Pi in P:
+                    d = qSign * HSR.Distance(Vector(Pi), Q)
+                    if d >= -EPS:
+                        n += 1
+                pVerticesInFrontPlaneQ = (n == len(P))
+
+                if pVerticesInFrontPlaneQ:
+                    debug("\nTest 4bis\n")
+                    debug("P IN FRONT OF Q!\n")
+
+                # We don't even know if Q does obscure P, so they should
+                # intersect each other, split one of them in two parts.
+                if not qVerticesBehindPlaneP and not pVerticesInFrontPlaneQ:
+                    debug("\nSimple Intersection?\n")
+                    debug("Test 3bis or 4bis failed\n")
+                    debug("Split here!!2\n")
+
+                    facelist = HSR.facesplit(P, Q, facelist, nmesh)
+                    split_done = 1
+                    break
+
+                facelist.remove(Q)
+                facelist.insert(0, Q)
+                Q.smooth = 1
+                face_marked = 1
+                debug("Q marked!\n")
+                break
+
+            # Write P!
+            if split_done == 0 and face_marked == 0:
+                facelist.remove(P)
+                maplist.append(P)
+                dumpfaces(maplist, "dump" + str(len(maplist)).zfill(4) + ".svg")
+
+                progress.update()
+
+            if len(facelist) == 870:
+                dumpfaces([P, Q], "loopdebug.svg")
+
+            #if facelist == None:
+            #    maplist = [P, Q]
+            #    print [v.co for v in P]
+            #    print [v.co for v in Q]
+            #    break
+
+            # end of while len(facelist)
+
+        nmesh.faces = maplist
+        #for f in nmesh.faces:
+        #    f.sel = 1
+
+        nmesh.update()
+
+    def _doHiddenSurfaceRemoval(self, mesh):
+        """Do HSR for the given mesh.
+        """
+        if len(mesh.faces) == 0:
+            return
+
+        if config.polygons['HSR'] == 'PAINTER':
+            print "\nUsing the Painter algorithm for HSR."
+            self.__simpleDepthSort(mesh)
+
+        elif config.polygons['HSR'] == 'NEWELL':
+            print "\nUsing the Newell's algorithm for HSR."
+            self.__newellDepthSort(mesh)
+
+    def _doEdgesStyle(self, mesh, edgestyleSelect):
+        """Process Mesh Edges accroding to a given selection style.
+
+        Examples of algorithms:
+
+        Contours:
+            given an edge if its adjacent faces have the same normal (that is
+            they are complanar), than deselect it.
+
+        Silhouettes:
+            given an edge if one its adjacent faces is frontfacing and the
+            other is backfacing, than select it, else deselect.
+        """
+
+        Mesh.Mode(Mesh.SelectModes['EDGE'])
+
+        edge_cache = MeshUtils.buildEdgeFaceUsersCache(mesh)
+
+        for i, edge_faces in enumerate(edge_cache):
+            mesh.edges[i].sel = 0
+            if edgestyleSelect(edge_faces):
+                mesh.edges[i].sel = 1
+
+        """
+        for e in mesh.edges:
+
+            e.sel = 0
+            if edgestyleSelect(e, mesh):
+                e.sel = 1
+        """
+        #
+
+
+# ---------------------------------------------------------------------
+#
+## GUI Class and Main Program
+#
+# ---------------------------------------------------------------------
+
+from Blender import BGL, Draw
+from Blender.BGL import *
+
+
+class GUI:
+
+    def _init():
+
+        # Output Format menu
+        output_format = config.output['FORMAT']
+        default_value = outputWriters.keys().index(output_format) + 1
+        GUI.outFormatMenu = Draw.Create(default_value)
+        GUI.evtOutFormatMenu = 0
+
+        # Animation toggle button
+        GUI.animToggle = Draw.Create(config.output['ANIMATION'])
+        GUI.evtAnimToggle = 1
+
+        # Join Objects toggle button
+        GUI.joinObjsToggle = Draw.Create(config.output['JOIN_OBJECTS'])
+        GUI.evtJoinObjsToggle = 2
+
+        # Render filled polygons
+        GUI.polygonsToggle = Draw.Create(config.polygons['SHOW'])
+
+        # Shading Style menu
+        shading_style = config.polygons['SHADING']
+        default_value = shadingStyles.keys().index(shading_style) + 1
+        GUI.shadingStyleMenu = Draw.Create(default_value)
+        GUI.evtShadingStyleMenu = 21
+
+        GUI.evtPolygonsToggle = 3
+        # We hide the config.polygons['EXPANSION_TRICK'], for now
+
+        # Render polygon edges
+        GUI.showEdgesToggle = Draw.Create(config.edges['SHOW'])
+        GUI.evtShowEdgesToggle = 4
+
+        # Render hidden edges
+        GUI.showHiddenEdgesToggle = Draw.Create(config.edges['SHOW_HIDDEN'])
+        GUI.evtShowHiddenEdgesToggle = 5
+
+        # Edge Style menu
+        edge_style = config.edges['STYLE']
+        default_value = edgeStyles.keys().index(edge_style) + 1
+        GUI.edgeStyleMenu = Draw.Create(default_value)
+        GUI.evtEdgeStyleMenu = 6
+
+        # Edge Width slider
+        GUI.edgeWidthSlider = Draw.Create(config.edges['WIDTH'])
+        GUI.evtEdgeWidthSlider = 7
+
+        # Edge Color Picker
+        c = config.edges['COLOR']
+        GUI.edgeColorPicker = Draw.Create(c[0] / 255.0, c[1] / 255.0, c[2] / 255.0)
+        GUI.evtEdgeColorPicker = 71
+
+        # Render Button
+        GUI.evtRenderButton = 8
+
+        # Exit Button
+        GUI.evtExitButton = 9
+
+        # Save default button
+        GUI.evtSaveDefaultButton = 99
+
+    def draw():
+
+        # initialize static members
+        GUI._init()
+
+        glClear(GL_COLOR_BUFFER_BIT)
+        glColor3f(0.0, 0.0, 0.0)
+        glRasterPos2i(10, 380)
+        Draw.Text("VRM: Vector Rendering Method script. Version %s." %
+                __version__)
+        glRasterPos2i(10, 365)
+        Draw.Text("%s (c) 2012" % __author__)
+
+        glRasterPos2i(10, 335)
+        Draw.Text("Press Q or ESC to quit.")
+
+        # Build the output format menu
+        glRasterPos2i(10, 310)
+        Draw.Text("Select the output Format:")
+        outMenuStruct = "Output Format %t"
+        for t in outputWriters.keys():
+            outMenuStruct = outMenuStruct + "|%s" % t
+        GUI.outFormatMenu = Draw.Menu(outMenuStruct, GUI.evtOutFormatMenu,
+            10, 285, 160, 18, GUI.outFormatMenu.val, "Choose the Output Format")
+
+        # Animation toggle
+        GUI.animToggle = Draw.Toggle("Animation", GUI.evtAnimToggle,
+            10, 260, 160, 18, GUI.animToggle.val,
+            "Toggle rendering of animations")
+
+        # Join Objects toggle
+        GUI.joinObjsToggle = Draw.Toggle("Join objects", GUI.evtJoinObjsToggle,
+            10, 235, 160, 18, GUI.joinObjsToggle.val,
+            "Join objects in the rendered file")
+
+        # Render Button
+        Draw.Button("Render", GUI.evtRenderButton, 10, 210 - 25, 75, 25 + 18,
+            "Start Rendering")
+        Draw.Button("Exit", GUI.evtExitButton, 95, 210 - 25, 75, 25 + 18, "Exit!")
+
+        Draw.Button("Save settings as default", GUI.evtSaveDefaultButton, 10, 210 - 50, 160, 18,
+            "Save settings as default")
+
+        # Rendering Styles
+        glRasterPos2i(200, 310)
+        Draw.Text("Rendering Style:")
+
+        # Render Polygons
+        GUI.polygonsToggle = Draw.Toggle("Filled Polygons", GUI.evtPolygonsToggle,
+            200, 285, 160, 18, GUI.polygonsToggle.val,
+            "Render filled polygons")
+
+        if GUI.polygonsToggle.val == 1:
+
+            # Polygon Shading Style
+            shadingStyleMenuStruct = "Shading Style %t"
+            for t in shadingStyles.keys():
+                shadingStyleMenuStruct = shadingStyleMenuStruct + "|%s" % t.lower()
+            GUI.shadingStyleMenu = Draw.Menu(shadingStyleMenuStruct, GUI.evtShadingStyleMenu,
+                200, 260, 160, 18, GUI.shadingStyleMenu.val,
+                "Choose the shading style")
+
+        # Render Edges
+        GUI.showEdgesToggle = Draw.Toggle("Show Edges", GUI.evtShowEdgesToggle,
+            200, 235, 160, 18, GUI.showEdgesToggle.val,
+            "Render polygon edges")
+
+        if GUI.showEdgesToggle.val == 1:
+
+            # Edge Style
+            edgeStyleMenuStruct = "Edge Style %t"
+            for t in edgeStyles.keys():
+                edgeStyleMenuStruct = edgeStyleMenuStruct + "|%s" % t.lower()
+            GUI.edgeStyleMenu = Draw.Menu(edgeStyleMenuStruct, GUI.evtEdgeStyleMenu,
+                200, 210, 160, 18, GUI.edgeStyleMenu.val,
+                "Choose the edge style")
+
+            # Edge size
+            GUI.edgeWidthSlider = Draw.Slider("Width: ", GUI.evtEdgeWidthSlider,
+                200, 185, 140, 18, GUI.edgeWidthSlider.val,
+                0.0, 10.0, 0, "Change Edge Width")
+
+            # Edge Color
+            GUI.edgeColorPicker = Draw.ColorPicker(GUI.evtEdgeColorPicker,
+                342, 185, 18, 18, GUI.edgeColorPicker.val, "Choose Edge Color")
+
+            # Show Hidden Edges
+            GUI.showHiddenEdgesToggle = Draw.Toggle("Show Hidden Edges",
+                GUI.evtShowHiddenEdgesToggle,
+                200, 160, 160, 18, GUI.showHiddenEdgesToggle.val,
+                "Render hidden edges as dashed lines")
+
+    def event(evt, val):
+
+        if evt == Draw.ESCKEY or evt == Draw.QKEY:
+            Draw.Exit()
+        else:
+            return
+
+        Draw.Redraw(1)
+
+    def button_event(evt):
+
+        if evt == GUI.evtExitButton:
+            Draw.Exit()
+
+        elif evt == GUI.evtOutFormatMenu:
+            i = GUI.outFormatMenu.val - 1
+            config.output['FORMAT'] = outputWriters.keys()[i]
+            # Set the new output file
+            global outputfile
+            outputfile = Blender.sys.splitext(basename)[0] + "." + str(config.output['FORMAT']).lower()
+
+        elif evt == GUI.evtAnimToggle:
+            config.output['ANIMATION'] = bool(GUI.animToggle.val)
+
+        elif evt == GUI.evtJoinObjsToggle:
+            config.output['JOIN_OBJECTS'] = bool(GUI.joinObjsToggle.val)
+
+        elif evt == GUI.evtPolygonsToggle:
+            config.polygons['SHOW'] = bool(GUI.polygonsToggle.val)
+
+        elif evt == GUI.evtShadingStyleMenu:
+            i = GUI.shadingStyleMenu.val - 1
+            config.polygons['SHADING'] = shadingStyles.keys()[i]
+
+        elif evt == GUI.evtShowEdgesToggle:
+            config.edges['SHOW'] = bool(GUI.showEdgesToggle.val)
+
+        elif evt == GUI.evtShowHiddenEdgesToggle:
+            config.edges['SHOW_HIDDEN'] = bool(GUI.showHiddenEdgesToggle.val)
+
+        elif evt == GUI.evtEdgeStyleMenu:
+            i = GUI.edgeStyleMenu.val - 1
+            config.edges['STYLE'] = edgeStyles.keys()[i]
+
+        elif evt == GUI.evtEdgeWidthSlider:
+            config.edges['WIDTH'] = float(GUI.edgeWidthSlider.val)
+
+        elif evt == GUI.evtEdgeColorPicker:
+            config.edges['COLOR'] = [int(c * 255.0) for c in GUI.edgeColorPicker.val]
+
+        elif evt == GUI.evtRenderButton:
+            label = "Save %s" % config.output['FORMAT']
+            # Show the File Selector
+            global outputfile
+            Blender.Window.FileSelector(vectorize, label, outputfile)
+
+        elif evt == GUI.evtSaveDefaultButton:
+            config.saveToRegistry()
+
+        else:
+            print "Event: %d not handled!" % evt
+
+        if evt:
+            Draw.Redraw(1)
+            #GUI.conf_debug()
+
+    def conf_debug():
+        from pprint import pprint
+        print "\nConfig"
+        pprint(config.output)
+        pprint(config.polygons)
+        pprint(config.edges)
+
+    _init = staticmethod(_init)
+    draw = staticmethod(draw)
+    event = staticmethod(event)
+    button_event = staticmethod(button_event)
+    conf_debug = staticmethod(conf_debug)
+
+
+# A wrapper function for the vectorizing process
+def vectorize(filename):
+    """The vectorizing process is as follows:
+
+     - Instanciate the writer and the renderer
+     - Render!
+     """
+
+    if filename == "":
+        print "\nERROR: invalid file name!"
+        return
+
+    from Blender import Window
+    editmode = Window.EditMode()
+    if editmode:
+        Window.EditMode(0)
+
+    actualWriter = outputWriters[config.output['FORMAT']]
+    writer = actualWriter(filename)
+
+    renderer = Renderer()
+    renderer.doRendering(writer, config.output['ANIMATION'])
+
+    if editmode:
+        Window.EditMode(1)
+
+
+# Here the main
+if __name__ == "__main__":
+
+    global progress
 
-        vectorize("proba.svg")
-        if editmode: Window.EditMode(1) 
+    config.loadFromRegistry()
 
+    # initialize writer setting also here to configure writer specific
+    # settings on startup
+    actualWriter = outputWriters[config.output['FORMAT']]
+    writer = actualWriter("")
 
+    outputfile = ""
+    basename = Blender.sys.basename(Blender.Get('filename'))
+    if basename != "":
+        outputfile = Blender.sys.splitext(basename)[0] + "." + str(config.output['FORMAT']).lower()
 
+    if Blender.mode == 'background':
+        progress = ConsoleProgressIndicator()
+        vectorize(outputfile)
+    else:
+        progress = GraphicalProgressIndicator()
+        Draw.Register(GUI.draw, GUI.event, GUI.button_event)