Some improvements in the SVG writer
[vrm.git] / vrm.py
diff --git a/vrm.py b/vrm.py
index 726c83d..d85b085 100755 (executable)
--- a/vrm.py
+++ b/vrm.py
 #!BPY
-
 """
 Name: 'VRM'
-Blender: 237
+Blender: 241
 Group: 'Export'
-Tooltip: 'Vector Rendering Method Export Script'
+Tooltip: 'Vector Rendering Method Export Script 0.3'
 """
 
+# ---------------------------------------------------------------------
+#    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
+#
+# ---------------------------------------------------------------------
+#
+#    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 Anthony C. D'Agostino for the original backface.py script   
+#
+# ---------------------------------------------------------------------
+
 import Blender
-from Blender import Scene, Object, Lamp, Camera
+from Blender import Scene, Object, NMesh, Lamp, Camera
+from Blender.Mathutils import *
 from math import *
-from Blender.Window import *
-from Blender.Scene import Render
 
 
-# distance from camera Z'
-def Distance(PX,PY,PZ):
+# ---------------------------------------------------------------------
+#
+## 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, obMesh, canvasSize):
+        """Calculate the projection matrix.
+
+        The projection matrix depends, in this case, on the camera settings,
+        and also on object transformation matrix.
+        """
+
+        self.size = canvasSize
+
+        camera = cameraObj.getData()
+
+        aspect = float(canvasSize[0])/float(canvasSize[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) 
+        
+
+        # View transformation
+        cam = Matrix(cameraObj.getInverseMatrix())
+        cam.transpose() 
+
+        m1 = Matrix(obMesh.getMatrix())
+        m1.transpose()
+        
+        mP = cam * m1
+        mP = m2  * mP
+
+        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 need the vertex expressed using homogeneous coordinates
+        p = self.projectionMatrix * Vector([v[0], v[1], v[2], 1.0])
+        
+        mW = self.size[0]/2
+        mH = self.size[1]/2
+        
+        if p[3]<=0:
+            p[0] = round(p[0]*mW)+mW
+            p[1] = round(p[1]*mH)+mH
+        else:
+            p[0] = round((p[0]/p[3])*mW)+mW
+            p[1] = round((p[1]/p[3])*mH)+mH
+            
+        # For now we want (0,0) in the top-left corner of the canvas
+        # Mirror and translate along y
+        p[1] *= -1
+        p[1] += self.size[1]
+    
+        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."""
+        
+        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)
+
+        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
+
+
+# ---------------------------------------------------------------------
+#
+## Object representation class
+#
+# ---------------------------------------------------------------------
+
+# TODO: a class to represent the needed properties of a 2D vector image
+# Just use a NMesh 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:
+        - printCanvas(mesh) --- where mesh is as specified before.
+    """
+    
+    def __init__(self, fileName, canvasSize):
+        """Open the file named #fileName# and set the canvas size."""
+        
+        self.file = open(fileName, "w")
+        print "Outputting to: ", fileName
+
+        self.canvasSize = canvasSize
+    
+
+    ##
+    # Public Methods
+    #
+    
+    def printCanvas(mesh):
+        return
+        
+    ##
+    # Private Methods
+    #
+    
+    def _printHeader():
+        return
+
+    def _printFooter():
+        return
+
+
+## SVG Writer
+
+class SVGVectorWriter(VectorWriter):
+    """A concrete class for writing SVG output.
+
+    The class does not support animations, yet.
+    Sorry.
+    """
+
+    def __init__(self, file, canvasSize):
+        """Simply call the parent Contructor."""
+        VectorWriter.__init__(self, file, canvasSize)
+
+
+    ##
+    # Public Methods
+    #
     
-    dist = sqrt(PX*PX+PY*PY+PZ*PZ)
-    return dist
+    def printCanvas(self, scene):
+        """Convert the scene representation to SVG."""
+
+        self._printHeader()
+        
+        Objects = scene.getChildren()
+        for obj in Objects:
+            self.file.write("<g>\n")
+            
+            for face in obj.getData().faces:
+                self._printPolygon(face)
+
+            self._printWireframe(obj.getData())
+            
+            self.file.write("</g>\n")
+        
+        self._printFooter()
+    
+    ##  
+    # Private Methods
+    #
+    
+    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)
+
+    def _printFooter(self):
+        """Print the SVG footer."""
+
+        self.file.write("\n</svg>\n")
+        self.file.close()
+
+    def _printWireframe(self, mesh):
+        """Print the wireframe using mesh edges... is this the correct way?
+        """
+
+        print mesh.edges
+        print
+        print mesh.verts
+        
+        stroke_width=0.5
+        stroke_col = [0, 0, 0]
+        
+        self.file.write("<g>\n")
+
+        for e in mesh.edges:
+            self.file.write("<line x1=\"%g\" y1=\"%g\" x2=\"%g\" y2=\"%g\"\n"
+                    % ( e.v1[0], e.v1[1], e.v2[0], e.v2[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("\"/>\n")
+
+        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:
+            self.file.write("%g,%g " % (v[0], v[1]))
+        
+        self.file.seek(-1,1) # get rid of the last space
+        self.file.write("\"\n")
+        
+        #take as face color the first vertex color
+        fcol = face.col[0]
+        color = [fcol.r, fcol.g, fcol.b]
+
+        stroke_col = [0, 0, 0]
+        if not wireframe:
+            stroke_col = color
+
+        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")
+
+
+# ---------------------------------------------------------------------
+#
+## Rendering Classes
+#
+# ---------------------------------------------------------------------
 
 def RotatePoint(PX,PY,PZ,AngleX,AngleY,AngleZ):
     
@@ -41,206 +374,325 @@ def RotatePoint(PX,PY,PZ,AngleX,AngleY,AngleZ):
     NewPoint.append(NewZ)
     return NewPoint
 
-def vetmatmult(v, M):
-    
-    v2 = [0, 0, 0, 0]
+class Renderer:
+    """Render a scene viewed from a given camera.
     
-    for i in range(0, 3):
-        for j in range(0, 3):
-            v2[i] += (v[i]*M[i][j])
+    This class is responsible of the rendering process, hence transormation
+    and projection of the ojects in the scene are invoked by the renderer.
+
+    The user can optionally provide a specific camera for the rendering, see
+    the #doRendering# method for more informations.
+    """
+
+    def __init__(self):
+        """Set the canvas size to a defaulr value.
+        
+        The only instance attribute here is the canvas size, which can be
+        queryed to the renderer by other entities.
+        """
+        self.canvasSize = (0.0, 0.0)
+
+
+    ##
+    # Public Methods
+    #
+
+    def getCanvasSize(self):
+        """Return the current canvas size read from Blender rendering context"""
+        return self.canvasSize
+        
+    def doRendering(self, scene, cameraObj=None):
+        """Control the rendering process.
+        
+        Here we control the entire rendering process invoking the operation
+        needed to transforma project the 3D scene in two dimensions.
+
+        Parameters:
+        scene --- the Blender Scene to render
+        cameraObj --- the camera object to use for the viewing processing
+        """
+
+        if cameraObj == None:
+            cameraObj = scene.getCurrentCamera()
+        
+        context = scene.getRenderingContext()
+        self.canvasSize = (context.imageSizeX(), context.imageSizeY())
+        
+        Objects = scene.getChildren()
+        
+        # A structure to store the transformed scene
+        newscene = Scene.New("flat"+scene.name)
+        
+        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(cameraObj, obj, self.canvasSize)
+
+            # Let's store the transformed data
+            transformed_mesh = NMesh.New("flat"+obj.name)
+            transformed_mesh.hasVertexColours(1)
+
+            # process Edges
+            for v in obj.getData().verts:
+                transformed_mesh.verts.append(v)
+            transformed_mesh.edges = self._processEdges(obj.getData().edges)
+            print transformed_mesh.edges
 
-    return v2
+            
+            # Store the materials
+            materials = obj.getData().getMaterials()
+
+            meshfaces = obj.getData().faces
+
+            for face in meshfaces:
 
-def flatern(vertx, verty, vertz):
+                # if the face is visible flatten it on the "picture plane"
+                if self._isFaceVisible_old(face, obj, cameraObj):
+                    
+                    # Store transformed face
+                    newface = NMesh.Face()
 
-    cam = Camera.get()            # Get the cameras in scene
-    Lens = cam[0].getLens()       # The First Blender camera lens
+                    for vert in face:
 
-    camTyp = cam[0].getType()
+                        p = proj.doProjection(vert.co)
 
-    msize = (context.imageSizeX(), context.imageSizeY())
-    xres = msize[0]             # X res for output
-    yres = msize[1]                # Y res for output
-    ratio = xres/yres
+                        tmp_vert = NMesh.Vert(p[0], p[1], p[2])
 
-    fov = atan(ratio * 16.0 / Lens)  # Get fov stuff
+                        # 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 newscene
+
+
+    ##
+    # Private Methods
+    #
+
+    def _isFaceVisible_old(self, face, obj, cameraObj):
+        """Determine if the face is visible from the current camera.
+
+        The following code is taken basicly from the original vrm script.
+        """
+
+        camera = cameraObj
+
+        numvert = len(face)
+
+        # backface culling
+
+        # translate and rotate according to the object matrix
+        # and then translate according to the camera position
+        #m = obj.getMatrix()
+        #m.transpose()
+        
+        #a = m*Vector(face[0]) - Vector(cameraObj.loc)
+        #b = m*Vector(face[1]) - Vector(cameraObj.loc)
+        #c = m*Vector(face[numvert-1]) - Vector(cameraObj.loc)
+        
+        a = []
+        a.append(face[0][0])
+        a.append(face[0][1])
+        a.append(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(face[1][0])
+        b.append(face[1][1])
+        b.append(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(face[numvert-1][0])
+        c.append(face[numvert-1][1])
+        c.append(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]
+        #d = DotVecs(Vector(norm), Vector(a))
+
+        return (d<0)
     
-    dist = xres/2*tan(fov)         # Calculate dist from pinhole camera to image plane
+    def _isFaceVisible(self, face, obj, cameraObj):
+        """Determine if the face is visible from the current camera.
 
-    screenxy=[0,0]
-    x=-vertx
-    y=verty
-    z=vertz
+        The following code is taken basicly from the original vrm script.
+        """
 
-    #----------------------------        
-    # calculate x'=dist*x/z & y'=dist*x/z
-    #----------------------------
-    screenxy[0]=int(xres/2.0+4*x*dist/z)
-    screenxy[1]=int(yres/2.0+4*y*dist/z)
-    return screenxy
+        camera = cameraObj
 
+        numvert = len(face)
 
-########
-# Main #
-########
+        # backface culling
 
-scena = Scene.GetCurrent()
-context = scena.getRenderingContext()
-renderDir = context.getRenderPath()
+        # translate and rotate according to the object matrix
+        # and then translate according to the camera position
+        m = obj.getMatrix()
+        m.transpose()
+        
+        a = m*Vector(face[0]) - Vector(cameraObj.loc)
+        b = m*Vector(face[1]) - Vector(cameraObj.loc)
+        c = m*Vector(face[numvert-1]) - Vector(cameraObj.loc)
 
-msize = (context.imageSizeX(), context.imageSizeY())
+        norm = m*Vector(face.no)
 
-file=open("proba.svg","w")
+        d = DotVecs(norm, a)
 
-file.write("<?xml version=\"1.0\"?>\n")
-file.write("<svg width=\"" + `msize[0]` + "\" height=\"" + `msize[1]` + "\"\n")
-file.write("\txmlns=\"http://www.w3.org/2000/svg\" version=\"1.2\" streamable=\"true\">\n")
-#file.write("<pageSet>\n")
+        return (d<0)
 
-Objects = Blender.Object.Get()
-NUMobjects = len(Objects)
 
-startFrm = context.startFrame()
-endFrm = startFrm
-#endFrm = context.endFrame()
-frames = range(startFrm, endFrm+1)
+    def _doClipping():
+        return
 
-# are we rendering an animation ?
-animation = (len(frames) > 1)
 
-camera = scena.getCurrentCamera() # Get the current camera
+    # Per object methods
 
-for f in frames:
-    context.currentFrame(f)
-    Blender.Set('curframe', f)
+    def _doVisibleSurfaceDetermination(object):
+        return
 
-    DrawProgressBar (f/len(frames),"Rendering ..." + str(f))
+    def _doColorizing(object):
+        return
 
-    print "Frame: ", f, "\n"
-    if animation :
-        file.write("<g id=\"Frame" + str(f) + "\" style=\"visibility:hidden\">\n")
+    def _doStylizingEdges(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).
 
-    for o in Objects:
+        input: an edge list
+        return: a processed edge list
+        """
+        return
 
-        if o.getType() == "Mesh":
 
-            obj = o                  # Get the first selected object
-            objname = obj.name                # The object name
 
+# ---------------------------------------------------------------------
+#
+## Main Program
+#
+# ---------------------------------------------------------------------
 
-            OBJmesh = obj.getData()           # Get the mesh data for the object
-            meshfaces = OBJmesh.faces        # The number of faces in the object
 
-            #------------
-            # 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"
-
-
-            for face in range(0, len(meshfaces)):
-                numvert = len(OBJmesh.faces[face])
+# FIXME: really hackish code, just to test if the other parts work
+def depthSorting(scene):
+
+    cameraObj = Scene.GetCurrent().getCurrentCamera()
+    Objects = scene.getChildren()
+
+    Objects.sort(lambda obj1, obj2: 
+            cmp(Vector(Vector(cameraObj.loc) - Vector(obj1.loc)).length,
+                Vector(Vector(cameraObj.loc) - Vector(obj2.loc)).length
+                )
+            )
+    
+    # hackish sorting of faces according to the max z value of a vertex
+    for o in Objects:
+
+        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])))
                 
-                #if (isVisible(face)):
-                #    print "face visible"
-
-                # backface culling
-                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]
+                # 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
+    for o in scene.getChildren():
+        scene.unlink(o)
+    for o in Objects:
+        scene.link(o)
+    
+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.
+     """
+
+    print "Filename: %s" % filename
+    
+    scene = Scene.GetCurrent()
+    renderer = Renderer()
+    
+    flatScene = renderer.doRendering(scene)
+    canvasSize = renderer.getCanvasSize()
+
+    depthSorting(flatScene)
+
+    writer = SVGVectorWriter(filename, canvasSize)
+    writer.printCanvas(flatScene)
+
+    Blender.Scene.unlink(flatScene)
+    del flatScene
+
+# 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")
+    except:
+        vectorize("proba.svg")
 
-                # if the face is visible flatten it on the "picture plane"
-                if d < 0:
-                    file.write("<polygon points=\"")
-                    for vert in range(numvert):
-
-                        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)
-
-                        # original setting for translate
-                        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)
-
-                        #dist = Distance(vertxyz[0], vertxyz[1], vertxyz[2])
-                        xy = flatern(vertxyz[0], vertxyz[1], vertxyz[2])
-                        px = int(xy[0])
-                        py = int(xy[1])
-                        # add/sorting in Z' direction
-                        #Dodaj(px,py,Distance(vertxyz[0], vertxyz[1], vertxyz[2]))
-                        file.write(`px` + ", " + `py`)
-
-                    # per face color calculation
-                    ambient = -200
-                    #svetlo = [1, 1, -1] #original
-                    svetlo = [1, 1, -0.3]
-                    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))
-                    if intensity < 0:
-                        intensity = 0
-                    
-                    wireframe = True
-                    if wireframe:
-                        stroke_width=1
-                    else: 
-                        stroke_width=0
-                    file.write("\"\n style=\"fill:rgb("+str(intensity)+","+str(intensity)+","+str(intensity)+");stroke:rgb(0,0,0);stroke-width:"+str(stroke_width)+"\"/>\n")
-    if animation:
-        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")
-
-file.write("</svg>")
-file.close()
-DrawProgressBar (1.0,"Finished.")
-print "Finished\n"