Add lightning and do some more refactoring
[vrm.git] / vrm.py
diff --git a/vrm.py b/vrm.py
index bbff105..69099c4 100755 (executable)
--- a/vrm.py
+++ b/vrm.py
 #!BPY
-
 """
 Name: 'VRM'
-Blender: 237
+Blender: 241
 Group: 'Export'
 Tooltip: 'Vector Rendering Method Export Script'
 """
 
+__author__ = "Antonio Ospite"
+__url__ = ["blender"]
+__version__ = "0.3"
+
+__bpydoc__ = """\
+    Render the scene and save the result in vector format.
+"""
+
+# ---------------------------------------------------------------------
+#    Copyright (c) 2006 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
+#    the Free Software Foundation; either version 2 of the License, or
+#    (at your option) any later version.
+#
+#    This program is distributed in the hope that it will be useful,
+#    but WITHOUT ANY WARRANTY; without even the implied warranty of
+#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+#    GNU General Public License for more details.
+#
+#    You should have received a copy of the GNU General Public License
+#    along with this program; if not, write to the Free Software
+#    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+#
+# ---------------------------------------------------------------------
+#
+# 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.
+#
+# ---------------------------------------------------------------------
+# 
+# Things TODO for a next release:
+#   - Switch to the Mesh structure, should be considerably faster
+#    (partially done, but cannot sort faces, yet)
+#   - Use a better depth sorting algorithm
+#   - Review how selections are made (this script uses selection states of
+#     primitives to represent visibility infos)
+#   - Implement Clipping and do handle object intersections
+#   - Implement Edge Styles (silhouettes, contours, etc.)
+#   - Implement Edge coloring
+#   - Use multiple lighting sources in color calculation
+#   - Implement Shading Styles?
+#   - Use another representation for the 2D projection? 
+#     Think to a way to merge adjacent polygons that have the same color.
+#   - Add other Vector Writers.
+#
+# ---------------------------------------------------------------------
+#
+# Changelog:
+#
+#   vrm-0.3.py  -   2006-05-19
+#    * First release after code restucturing.
+#      Now the script offers a useful set of functionalities
+#      and it can render animations, too.
+#
+# ---------------------------------------------------------------------
 
 import Blender
-from Blender import Scene, Object, Lamp, Camera
+from Blender import Scene, Object, Mesh, NMesh, Material, Lamp, Camera
+from Blender.Mathutils import *
 from math import *
-from Blender.Window import *
-from Blender.Scene import Render
-   
-def init():
 
-    print "Init\n"
 
-    renderDir = context.getRenderPath()
+# Some global settings
+PRINT_POLYGONS     = True
+PRINT_EDGES        = False
+SHOW_HIDDEN_EDGES  = False
+
+EDGES_WIDTH = 0.5
+
+POLYGON_EXPANSION_TRICK = True
+
+RENDER_ANIMATION = False
+
+# Do not work for now!
+OPTIMIZE_FOR_SPACE = False
+
+
+# ---------------------------------------------------------------------
+#
+## 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
+        
+        # What projection do we want?
+        if camera.type:
+            #mP = self._calcOrthoMatrix(fovy, aspect, near, far, 17) #camera.scale) 
+            mP = self._calcOrthoMatrix(fovy, aspect, near, far, scale) 
+        else:
+            mP = self._calcPerspectiveMatrix(fovy, aspect, near, far) 
+        
+
+        # 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
+        p = self.projectionMatrix * Vector(v).resize4D()
+
+        if p[3]>0:
+            p[0] = p[0]/p[3]
+            p[1] = p[1]/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
+
+
+# ---------------------------------------------------------------------
+#
+## 2DObject 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"""
+
+        self.outputFileName = fileName
+        self.file = None
+        
+        context = Scene.GetCurrent().getRenderingContext()
+        self.canvasSize = ( context.imageSizeX(), context.imageSizeY() )
+
+        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
+
+        self.file = open(self.outputFileName, "w")
+        print "Outputting to: ", self.outputFileName
+
+        return
+
+    def close(self):
+        self.file.close()
+        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, file):
+        """Simply call the parent Contructor.
+        """
+        VectorWriter.__init__(self, file)
+
+
+    ##
+    # Public Methods
+    #
+
+    def open(self, startFrame=1, endFrame=1):
+        """Do some initialization operations.
+        """
+        VectorWriter.open(self, startFrame, endFrame)
+        self._printHeader()
+
+    def close(self):
+        """Do some finalization operation.
+        """
+        self._printFooter()
+
+        
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False,
+            showHiddenEdges=False):
+        """Convert the scene representation to SVG.
+        """
+
+        Objects = scene.getChildren()
+
+        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 1.1//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)
+
+        if self.animation:
+
+            self.file.write("""\n<script><![CDATA[
+            globalStartFrame=%d;
+            globalEndFrame=%d;
+
+            /* FIXME: Use 1000 as interval as lower values gives problems */
+            timerID = setInterval("NextFrame()", 1000);
+            globalFrameCounter=%d;
+
+            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""" % (self.startFrame, self.endFrame, self.startFrame) )
+                
+    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("<polygon points=\"")
+
+            for v in face:
+                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("\"\n")
+            
+            # take as face color the first vertex color
+            # TODO: the average of vetrex colors?
+            if face.col:
+                fcol = face.col[0]
+                color = [fcol.r, fcol.g, fcol.b]
+            else:
+                color = [255, 255, 255]
+
+            # 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_col = color
+            stroke_width = 0.5
+
+            self.file.write("\tstyle=\"fill:rgb("+str(color[0])+","+str(color[1])+","+str(color[2])+");")
+            if POLYGON_EXPANSION_TRICK:
+                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")
+
+        self.file.write("</g>\n")
+
+    def _printEdges(self, mesh, showHiddenEdges=False):
+        """Print the wireframe using mesh edges.
+        """
+
+        stroke_width=EDGES_WIDTH
+        stroke_col = [0, 0, 0]
+        
+        self.file.write("<g>\n")
+
+        for e in mesh.edges:
+            
+            hidden_stroke_style = ""
+            
+            # Consider an edge selected if both vertices 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"
+
+            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")
+
+
+
+# ---------------------------------------------------------------------
+#
+## Rendering Classes
+#
+# ---------------------------------------------------------------------
+
+class Renderer:
+    """Render a scene viewed from a given camera.
     
+    This class is responsible of the rendering process, transformation and
+    projection of the objects in the scene are invoked by the renderer.
 
-# distance from camera Z'
-def Distance(PX,PY,PZ):
+    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, 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.getCurrentCamera()
+
+        # Get the list of lighting sources
+        obj_lst = self._SCENE.getChildren()
+        self.lights = [ o for o in obj_lst if o.getType() == 'Lamp']
+
+        if len(self.lights) == 0:
+            l = Lamp.New('Lamp')
+            lobj = Object.New('Lamp')
+            lobj.link(l) 
+            self.lights.append(lobj)
+
+
+    ##
+    # Public Methods
+    #
+
+    def doRendering(self, outputWriter, animation=False):
+        """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 only the
+              current frame.
+        """
+        
+        context = self._SCENE.getRenderingContext()
+        currentFrame = context.currentFrame()
+
+        # Handle the animation case
+        if not animation:
+            startFrame = currentFrame
+            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!"
+        for f in range(startFrame, endFrame+1):
+            context.currentFrame(f)
+
+            renderedScene = self.doRenderScene(self._SCENE)
+            outputWriter.printCanvas(renderedScene,
+                    doPrintPolygons = PRINT_POLYGONS,
+                    doPrintEdges    = PRINT_EDGES,
+                    showHiddenEdges = SHOW_HIDDEN_EDGES)
+            
+            # clear the rendered scene
+            self._SCENE.makeCurrent()
+            Scene.unlink(renderedScene)
+            del renderedScene
+
+        outputWriter.close()
+        print "Done!"
+        context.currentFrame(currentFrame)
+
+
+    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)
+
+        # 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.cameraObj, self.canvasRatio)
+
+
+        # Convert geometric object types to mesh Objects
+        geometricObjTypes = ['Mesh', 'Surf', 'Curve'] # TODO: add the Text type
+        Objects = workScene.getChildren()
+        objList = [ o for o in Objects if o.getType() in geometricObjTypes ]
+        for obj in objList:
+            old_obj = obj
+            obj = self._convertToRawMeshObj(obj)
+            workScene.link(obj)
+            workScene.unlink(old_obj)
+
+
+        # FIXME: does not work!!, Blender segfaults on joins
+        if OPTIMIZE_FOR_SPACE:
+            self._joinMeshObjectsInScene(workScene)
+
+        
+        # global processing of the scene
+        self._doClipping()
+
+        self._doSceneDepthSorting(workScene)
+        
+        # Per object activities
+        Objects = workScene.getChildren()
+
+        for obj in Objects:
+            
+            if obj.getType() not in geometricObjTypes:
+                print "Only geometric Objects supported! - Skipping type:", obj.getType()
+                continue
+
+            print "Rendering: ", obj.getName()
+
+            mesh = obj.data
+
+            self._doModelToWorldCoordinates(mesh, obj.matrix)
+
+            self._doObjectDepthSorting(mesh)
+            
+            self._doBackFaceCulling(mesh)
+            
+            self._doColorAndLighting(mesh)
+
+            # TODO: 'style' can be a function that determine
+            # if an edge should be showed?
+            self._doEdgesStyle(mesh, style=None)
+
+            self._doProjection(mesh, proj)
+            
+            # Update the object data, important! :)
+            mesh.update()
+
+        return workScene
+
+
+    ##
+    # Private Methods
+    #
+
+    # Utility methods
+
+    def _worldPosition(self, obj):
+        """Return the obj position in World coordinates.
+        """
+        return obj.matrix.translationPart()
+
+    def _cameraWorldPosition(self):
+        """Return the camera position in World coordinates.
+
+        This trick is needed when the camera follows a path and then
+        camera.loc does not correspond to the current real position of the
+        camera in the world.
+        """
+        return self._worldPosition(self.cameraObj)
+
+
+    # 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)
+        c = self._cameraWorldPosition()
+
+        # View vector in orthographics projections can be considered simply as the
+        # camera position
+        view_vect = Vector(c)
+        #if self.cameraObj.data.getType() == 1:
+        #    view_vect = Vector(c)
+
+        # View vector as in perspective projections
+        # it is the difference between the camera position and one point of
+        # the face, we choose the farthest point.
+        # TODO: make the code more pythonic :)
+        if self.cameraObj.data.getType() == 0:
+            max_len = 0
+            for vect in face:
+                vv = Vector(c) - Vector(vect.co)
+                if vv.length > max_len:
+                    max_len = vv.length
+                    view_vect = vv
+
+        # 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 _doClipping(self):
+        """Clip object against the View Frustum.
+        """
+        print "TODO: _doClipping()"
+        return
+
+    def _doSceneDepthSorting(self, scene):
+        """Sort objects in the scene.
+
+        The object sorting is done accordingly to the object centers.
+        """
+
+        c = self._cameraWorldPosition()
+
+        Objects = scene.getChildren()
+
+        #Objects.sort(lambda obj1, obj2: 
+        #        cmp((Vector(obj1.loc) - Vector(c)).length,
+        #            (Vector(obj2.loc) - Vector(c)).length
+        #            )
+        #        )
+        
+        Objects.sort(lambda obj1, obj2: 
+                cmp((self._worldPosition(obj1) - Vector(c)).length,
+                    (self._worldPosition(obj2) - Vector(c)).length
+                    )
+                )
+        
+        # update the scene
+        for o in Objects:
+            scene.unlink(o)
+            scene.link(o)
     
-    dist = sqrt(PX*PX+PY*PY+PZ*PZ)
-    return dist
 
-def Dodaj(x,y,z):
+    def _joinMeshObjectsInScene(self, scene):
+        """Merge all the Mesh Objects in a scene into a single Mesh Object.
+        """
+        bigObj = Object.New('Mesh', 'BigOne')
+        oList = [o for o in scene.getChildren() if o.getType()=='Mesh']
+        print "Before join", oList
+        bigObj.join(oList)
+        print "After join"
+        scene.link(bigObj)
+        for o in oList:
+            scene.unlink(o)
+
+    # Per object 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)
+
+        newObject.setMatrix(object.getMatrix())
+
+        return newObject
+
+    def _doModelToWorldCoordinates(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.
+        """
+        mesh.transform(matrix, True)
+
+    def _doObjectDepthSorting(self, mesh):
+        """Sort faces in an object.
+
+        The faces in the object are sorted following the distance of the
+        vertices from the camera position.
+        """
+        c = self._cameraWorldPosition()
+
+        # hackish sorting of faces
+        mesh.faces.sort(
+            lambda f1, f2:
+                # Sort faces according to the min distance from the camera
+                #cmp(min([(Vector(v.co)-Vector(c)).length for v in f1]),
+                #    min([(Vector(v.co)-Vector(c)).length for v in f2])))
+
+                # Sort faces according to the max distance from the camera
+                cmp(max([(Vector(v.co)-Vector(c)).length for v in f1]),
+                    max([(Vector(v.co)-Vector(c)).length for v in f2])))
+                
+                # Sort faces according to the avg distance from the camera
+                #cmp(sum([(Vector(v.co)-Vector(c)).length for v in f1])/len(f1),
+                #    sum([(Vector(v.co)-Vector(c)).length for v in f2])/len(f2)))
+
+        mesh.faces.reverse()
+
+    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 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):
+                f.sel = 1
+
+        # Is this the correct way to propagate the face selection info to the
+        # vertices belonging to a face ??
+        # TODO: Using the Mesh class this should come for free. Right?
+        Mesh.Mode(Mesh.SelectModes['VERTEX'])
+        for f in mesh.faces:
+            if not f.sel:
+                for v in f:
+                    v.sel = 0
+
+        for f in mesh.faces:
+            if f.sel:
+                for v in f:
+                    v.sel = 1
+
+    def _doColorAndLighting(self, mesh):
+        """Apply an Illumination model to the object.
+
+        The Illumination 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.hasVertexColours():
+            return
+        mesh.hasVertexColours(True)
+
+        materials = mesh.materials
+        
+        # TODO: use multiple lighting sources
+        light_obj = self.lights[0]
+        light_pos = self._worldPosition(light_obj)
+        light = light_obj.data
+
+        camPos = self._cameraWorldPosition()
+        
+        # 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 not mat:
+                mat = Material.New('defMat')
+            
+            L = Vector(light_pos).normalize()
+
+            V = (Vector(camPos) - Vector(f.v[0].co)).normalize()
+
+            N = Vector(f.no).normalize()
+
+            R = 2 * (N*L) * N - L
+
+            # TODO: Attenuation factor (not used for now)
+            a0 = 1; a1 = 0.0; a2 = 0.0
+            d = (Vector(f.v[0].co) - Vector(light_pos)).length
+            fd = min(1, 1.0/(a0 + a1*d + a2*d*d))
+
+            # Ambient component
+            Ia = 1.0
+            ka = mat.getAmb() * Vector([0.1, 0.1, 0.1])
+            Iamb = Ia * ka
+            
+            # Diffuse component (add light.col for kd)
+            kd = mat.getRef() * Vector(mat.getRGBCol())
+            Ip = light.getEnergy()
+            Idiff = Ip * kd * (N*L)
+            
+            # Specular component
+            ks = mat.getSpec() * Vector(mat.getSpecCol())
+            ns = mat.getHardness()
+            Ispec = Ip * ks * pow((V * R), ns)
+
+            # Emissive component
+            ki = Vector([mat.getEmit()]*3)
+
+            I = ki + Iamb + Idiff + Ispec
+
+            # Clamp I values between 0 and 1
+            I = [ min(c, 1) for c in I]
+            I = [ max(0, c) for c in I]
+            tmp_col = [ int(c * 255.0) for c in I]
+
+            vcol = NMesh.Col(tmp_col[0], tmp_col[1], tmp_col[2], 255)
+            f.col = []
+            for v in f.v:
+                f.col.append(vcol)
+
+    def _doEdgesStyle(self, mesh, style):
+        """Process Mesh Edges. (For now copy the edge data, in next version it
+        can be a place where recognize silouhettes and/or contours).
+
+        input: an edge list
+        return: a processed edge list
+        """
+        #print "\tTODO: _doEdgeStyle()"
+        return
+
+    def _doProjection(self, mesh, projector):
+        """Calculate the Projection for the object.
+        """
+        # TODO: maybe using the object.transform() can be faster?
+
+        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]
+
+
+
+# ---------------------------------------------------------------------
+#
+## Main Program
+#
+# ---------------------------------------------------------------------
+
+def vectorize(filename):
+    """The vectorizing process is as follows:
+     
+     - Instanciate the writer and the renderer
+     - Render!
+     """
+    from Blender import Window
+    editmode = Window.EditMode()
+    if editmode: Window.EditMode(0)
+
+    writer = SVGVectorWriter(filename)
     
-    print ""
+    renderer = Renderer()
+    renderer.doRendering(writer, RENDER_ANIMATION)
+
+    if editmode: Window.EditMode(1) 
+
+def vectorize_gui(filename):
+    """Draw the gui.
 
-def RotatePoint(PX,PY,PZ,AngleX,AngleY,AngleZ):
+    I would like to keep that simple, really.
+    """
+    Blender.Window.FileSelector (vectorize, 'Save SVG', filename)
+    Blender.Redraw()
+
+
+# Here the main
+if __name__ == "__main__":
     
-    NewPoint = []
-    # Rotate X
-    NewY = (PY * cos(AngleX))-(PZ * sin(AngleX))
-    NewZ = (PZ * cos(AngleX))+(PY * sin(AngleX))
-    # Rotate Y
-    PZ = NewZ
-    PY = NewY
-    NewZ = (PZ * cos(AngleY))-(PX * sin(AngleY))
-    NewX = (PX * cos(AngleY))+(PZ * sin(AngleY))
-    PX = NewX
-    PZ = NewZ
-    # Rotate Z
-    NewX = (PX * cos(AngleZ))-(PY * sin(AngleZ))
-    NewY = (PY * cos(AngleZ))+(PX * sin(AngleZ))
-    NewPoint.append(NewX)
-    NewPoint.append(NewY)
-    NewPoint.append(NewZ)
-    return NewPoint
-
-def flatern(vertx, verty, vertz):
-
-    cam = Camera.get()            # Get the cameras in scene
-    Lens = cam[0].getLens()       # The First Blender camera lens
-
-    camTyp = cam[0].getType()
-
-    msize = (context.imageSizeX(), context.imageSizeY())
-    xres = msize[0]             # X res for output
-    yres = msize[1]                # Y res for output
-    ratio = xres/yres
-
-    screenxy=[0,0]
-    x=-vertx
-    y=verty
-    z=vertz
-
-    fov = atan(ratio * 16.0 / Lens)  # Get fov stuff
-    dist = xres/2*tan(fov)         # Calculate dist from pinhole camera to image plane
-#----------------------------        
-# calculate x'=dist*x/z & y'=dist*x/z
-#----------------------------
-    screenxy[0]=int(xres/2+4*x*dist/z)
-    screenxy[1]=int(yres/2+4*y*dist/z)
-    return screenxy
-
-def writesvg(ob):
-
-    for i in range(0, ob[0]+1):
-      print ob[i], "\n"
-    print "WriteSVG\n"
-
-########
-# Main #
-########
-
-scena = Scene.GetCurrent()
-context = scena.getRenderingContext()
-
-#print dir(context)
-
-init()
-
-tacka = [0,0,0]
-lice = [3,tacka,tacka,tacka,tacka]
-
-msize = (context.imageSizeX(), context.imageSizeY())
-print msize
-
-file=open("proba.svg","w")
-
-file.write("<svg width=\"" + `msize[0]` + "\" height=\"" + `msize[1]` + "\"\n")
-file.write("xmlns=\"http://www.w3.org/2000/svg\" version=\"1.2\" streamable=\"true\">\n")
-#file.write("<pageSet>\n")
-
-Objects = Blender.Object.Get()
-NUMobjects = len(Objects)
-
-startFrm = context.startFrame()
-endFrm = startFrm
-#endFrm = context.endFrame()
-camera = scena.getCurrentCamera() # Get the current camera
-
-for f in range(startFrm, endFrm+1):
-  #scena.currentFrame(f)
-  Blender.Set('curframe', f)
-
-  DrawProgressBar (f/(endFrm+1-startFrm),"Rendering ..." + str(context.currentFrame()))
-
-  print "Frame: ", f, "\n"
-  if startFrm <> endFrm: file.write("<g id=\"Frame" + str(f) + "\" style=\"visibility:hidden\">\n")
-  for o in range(NUMobjects):
-
-    if Objects[o].getType() == "Mesh":
-
-      obj = Objects[o]                  # Get the first selected object
-      objname = obj.name                # The object name
-
-
-      OBJmesh = obj.getData()           # Get the mesh data for the object
-      numfaces=len(OBJmesh.faces)         # The number of faces in the object
-      numEachVert=len(OBJmesh.faces[0])    # The number of verts in each face
-
-      #------------
-      # Get the Material Colors
-      #------------
-#      MATinfo = OBJmesh.getMaterials()
-#    
-#      if len(MATinfo) > 0:
-#          RGB=MATinfo[0].rgbCol
-#          R=int(RGB[0]*255)
-#          G=int(RGB[1]*255)
-#          B=int(RGB[2]*255)
-#          color=`R`+"."+`G`+"."+`B`
-#          print color
-#      else:
-#          color="100.100.100"
-
-      objekat = []
-
-      objekat.append(0)
-
-      for face in range(numfaces):
-        numvert = len(OBJmesh.faces[face])
-        objekat.append(numvert)
-        objekat[0] += 1
-        
-# backface cutting
-        a = []
-        a.append(OBJmesh.faces[face][0][0])
-        a.append(OBJmesh.faces[face][0][1])
-        a.append(OBJmesh.faces[face][0][2])
-        a = RotatePoint(a[0], a[1], a[2], obj.RotX, obj.RotY, obj.RotZ)
-        a[0] += obj.LocX - camera.LocX
-        a[1] += obj.LocY - camera.LocY
-        a[2] += obj.LocZ - camera.LocZ
-        b = []
-        b.append(OBJmesh.faces[face][1][0])
-        b.append(OBJmesh.faces[face][1][1])
-        b.append(OBJmesh.faces[face][1][2])
-        b = RotatePoint(b[0], b[1], b[2], obj.RotX, obj.RotY, obj.RotZ)
-        b[0] += obj.LocX - camera.LocX
-        b[1] += obj.LocY - camera.LocY
-        b[2] += obj.LocZ - camera.LocZ
-        c = []
-        c.append(OBJmesh.faces[face][numvert-1][0])
-        c.append(OBJmesh.faces[face][numvert-1][1])
-        c.append(OBJmesh.faces[face][numvert-1][2])
-        c = RotatePoint(c[0], c[1], c[2], obj.RotX, obj.RotY, obj.RotZ)
-        c[0] += obj.LocX - camera.LocX
-        c[1] += obj.LocY - camera.LocY
-        c[2] += obj.LocZ - camera.LocZ
-
-        norm = [0,0,0]
-        norm[0] = (b[1] - a[1])*(c[2] - a[2]) - (c[1] - a[1])*(b[2] - a[2])
-        norm[1] = -((b[0] - a[0])*(c[2] - a[2]) - (c[0] - a[0])*(b[2] - a[2]))
-        norm[2] = (b[0] - a[0])*(c[1] - a[1]) - (c[0] - a[0])*(b[1] - a[1])
-
-        d = norm[0]*a[0] + norm[1]*a[1] + norm[2]*a[2]
-
-        if d < 0:
-          file.write("<polygon points=\"")
-          for vert in range(numvert):
-
-            objekat[0] += 3
-
-            vertxyz = []
-
-            if vert != 0: file.write(", ")
-
-            vertxyz.append(OBJmesh.faces[face][vert][0])
-            vertxyz.append(OBJmesh.faces[face][vert][1])
-            vertxyz.append(OBJmesh.faces[face][vert][2])
-
-# rotate object
-
-            vertxyz = RotatePoint(vertxyz[0], vertxyz[1], vertxyz[2], obj.RotX, obj.RotY, obj.RotZ)
-
-            vertxyz[0] += obj.LocX - camera.LocX
-            vertxyz[1] += obj.LocY - camera.LocY
-            vertxyz[2] += obj.LocZ - camera.LocZ
-
-# rotate camera
-
-            vertxyz = RotatePoint(vertxyz[0], vertxyz[1], vertxyz[2], -camera.RotX, -camera.RotY, -camera.RotZ)
-
-            objekat.append(Distance(vertxyz[0], vertxyz[1], vertxyz[2]))
-#            dist = Distance(vertxyz[0], vertxyz[1], vertxyz[2])
-            xy = flatern(vertxyz[0], vertxyz[1], vertxyz[2])
-            px = int(xy[0])
-            py = int(xy[1])
-            objekat.append(px)
-            objekat.append(py)
-            # add/sorting in Z' direction
-            #Dodaj(px,py,Distance(vertxyz[0], vertxyz[1], vertxyz[2]))
-            file.write(`px` + ", " + `py`)
-          ambient = -200
-          svetlo = [1,1,-1]
-          vektori = (norm[0]*svetlo[0]+norm[1]*svetlo[1]+norm[2]*svetlo[2])
-          vduzine = fabs(sqrt(pow(norm[0],2)+pow(norm[1],2)+pow(norm[2],2))*sqrt(pow(svetlo[0],2)+pow(svetlo[1],2)+pow(svetlo[2],2)))
-          intensity = floor(ambient + 255 * acos(vektori/vduzine))
-          print vektori/vduzine
-          if intensity < 0: intensity = 0
-          file.write("\"\n style=\"fill:rgb("+str(intensity)+","+str(intensity)+","+str(intensity)+");stroke:rgb(0,0,0);stroke-width:1\"/>\n")
-  if startFrm <> endFrm:
-    file.write("<animate attributeName=\"visibility\" begin=\""+str(f*0.08)+"s\" dur=\"0.08s\" fill=\"remove\" to=\"visible\">\n")
-    file.write("</animate>\n")
-    file.write("</g>\n")
-
-#flatern()
-#writesvg(objekat)
-file.write("</svg>")
-file.close()
-print file
-DrawProgressBar (1.0,"Finished.")
-print "Finished\n"
+    import os
+    outputfile = os.path.splitext(Blender.Get('filename'))[0]+".svg"
+
+    # with this trick we can run the script in batch mode
+    try:
+        vectorize_gui(outputfile)
+    except:
+        vectorize(outputfile)