Some stabilization work
[vrm.git] / vrm.py
diff --git a/vrm.py b/vrm.py
index 871131e..c694b77 100755 (executable)
--- a/vrm.py
+++ b/vrm.py
@@ -34,12 +34,12 @@ Tooltip: 'Vector Rendering Method Export Script 0.3'
 #
 # Additional credits:
 #   Thanks to Emilio Aguirre for S2flender from which I took inspirations :)
-#   Thanks to Anthony C. D'Agostino for the backface.py script   
+#   Thanks to Anthony C. D'Agostino for the original backface.py script   
 #
 # ---------------------------------------------------------------------
 
 import Blender
-from Blender import Scene, Object, NMesh, Lamp, Camera
+from Blender import Scene, Object, Mesh, NMesh, Lamp, Camera
 from Blender.Mathutils import *
 from math import *
 
@@ -60,18 +60,16 @@ class Projector:
     parameter list.
     """
 
-    def __init__(self, cameraObj, obMesh, canvasSize):
+    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.
         """
 
-        self.size = canvasSize
-
         camera = cameraObj.getData()
 
-        aspect = float(canvasSize[0])/float(canvasSize[1])
+        aspect = float(canvasRatio[0])/float(canvasRatio[1])
         near = camera.clipStart
         far = camera.clipEnd
 
@@ -84,17 +82,19 @@ class Projector:
         else:
             m2 = self._calcPerspectiveMatrix(fovy, aspect, near, far) 
         
-        m1 = Matrix()
-        mP = Matrix()
 
         # View transformation
-        cam = cameraObj.getInverseMatrix()
+        cam = Matrix(cameraObj.getInverseMatrix())
         cam.transpose() 
-
-        m1 = obMesh.getMatrix()
-        m1.transpose()
         
-        mP = cam * m1
+        # 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
 
         self.projectionMatrix = mP
@@ -111,23 +111,12 @@ class Projector:
         """
         
         # 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] = int(p[0]*mW)+mW
-            p[1] = int(p[1]*mH)+mH
-        else:
-            p[0] = int((p[0]/p[3])*mW)+mW
-            p[1] = int((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]
-    
+        p = self.projectionMatrix * Vector(v).resize4D()
+
+        if p[3]>0:
+            p[0] = p[0]/p[3]
+            p[1] = p[1]/p[3]
+
         return p
 
     ##
@@ -181,7 +170,7 @@ class Projector:
 
 # ---------------------------------------------------------------------
 #
-## Mesh representation class
+## Object representation class
 #
 # ---------------------------------------------------------------------
 
@@ -209,13 +198,15 @@ class VectorWriter:
         - printCanvas(mesh) --- where mesh is as specified before.
     """
     
-    def __init__(self, fileName, canvasSize):
+    def __init__(self, fileName):
         """Open the file named #fileName# and set the canvas size."""
         
         self.file = open(fileName, "w")
         print "Outputting to: ", fileName
 
-        self.canvasSize = canvasSize
+
+        context = Scene.GetCurrent().getRenderingContext()
+        self.canvasSize = ( context.imageSizeX(), context.imageSizeY() )
     
 
     ##
@@ -245,29 +236,45 @@ class SVGVectorWriter(VectorWriter):
     Sorry.
     """
 
-    def __init__(self, file, canvasSize):
+    def __init__(self, file):
         """Simply call the parent Contructor."""
-        VectorWriter.__init__(self, file, canvasSize)
+        VectorWriter.__init__(self, file)
 
 
     ##
     # Public Methods
     #
-    
-    def printCanvas(self, scene):
-        """Convert the scene representation to SVG."""
 
+    def open(self):
         self._printHeader()
+
+    def close(self):
+        self._printFooter()
+
         
-        for obj in scene:
+    
+    def printCanvas(self, scene, doPrintPolygons=True, doPrintEdges=False, showHiddenEdges=False):
+        """Convert the scene representation to SVG."""
+
+        Objects = scene.getChildren()
+        for obj in Objects:
+
+            if(obj.getType() != 'Mesh'):
+                continue
+            #
+
             self.file.write("<g>\n")
+
             
-            for face in obj.faces:
-                self._printPolygon(face)
+            if doPrintPolygons:
+                for face in obj.getData().faces:
+                    self._printPolygon(face)
 
+            if doPrintEdges:
+                self._printEdges(obj.getData(), showHiddenEdges)
+            
             self.file.write("</g>\n")
         
-        self._printFooter()
     
     ##  
     # Private Methods
@@ -277,7 +284,9 @@ class SVGVectorWriter(VectorWriter):
         """Print SVG header."""
 
         self.file.write("<?xml version=\"1.0\"?>\n")
-        self.file.write("<svg version=\"1.2\"\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)
@@ -288,32 +297,92 @@ class SVGVectorWriter(VectorWriter):
         self.file.write("\n</svg>\n")
         self.file.close()
 
+    def _printEdges(self, mesh, showHiddenEdges=False):
+        """Print the wireframe using mesh edges... is this the correct way?
+        """
+
+        stroke_width=0.5
+        stroke_col = [0, 0, 0]
+        
+        self.file.write("<g>\n")
+
+        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"
+
+            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")
+            
+        
+
     def _printPolygon(self, face):
         """Print our primitive, finally.
-
-        There is no color Handling for now, *FIX!*
         """
 
-        stroke_width=1
+        wireframe = False
+        
+        stroke_width=0.5
         
         self.file.write("<polygon points=\"")
 
-        i = 0
         for v in face:
-            if i != 0:
-                self.file.write(", ")
-
-            i+=1
-            
-            self.file.write("%g, %g" % (v[0], v[1]))
+            p = self._calcCanvasCoord(v)
+            self.file.write("%g,%g " % (p[0], p[1]))
         
-        color = [ int(c*255) for c in face.col]
-
+        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]
+
+        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(0,0,0);")
+        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\"/>\n")
+        self.file.write(" stroke-linecap:round;stroke-linejoin:round")
+        self.file.write("\"/>\n")
+
+    def _calcCanvasCoord(self, v):
+
+        pt = Vector([0, 0, 0])
+        
+        mW = self.canvasSize[0]/2
+        mH = self.canvasSize[1]/2
+
+        # 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
 
 
 # ---------------------------------------------------------------------
@@ -322,31 +391,10 @@ class SVGVectorWriter(VectorWriter):
 #
 # ---------------------------------------------------------------------
 
-def RotatePoint(PX,PY,PZ,AngleX,AngleY,AngleZ):
-    
-    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
-
 class Renderer:
     """Render a scene viewed from a given camera.
     
-    This class is responsible of the rendering process, hence transormation
+    This class is responsible of the rendering process, hence transformation
     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
@@ -354,56 +402,133 @@ class Renderer:
     """
 
     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.
+        """Make the rendering process only for the current scene by default.
         """
-        self.canvasSize = (0.0, 0.0)
+
+        # 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())
+
+        # Render from the currently active camera 
+        self.camera = self._SCENE.getCurrentCamera()
 
 
     ##
     # Public Methods
     #
 
-    def getCanvasSize(self):
-        """Return the current canvas size read from Blender rendering context"""
-        return self.canvasSize
+    def doRendering(self, outputWriter, animation=0):
+        """Render picture or animation and write it out.
         
-    def doRendering(self, scene, cameraObj=None):
-        """Control the rendering process.
+        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.
+        """
         
-        Here we control the entire rendering process invoking the operation
-        needed to transforma project the 3D scene in two dimensions.
+        context = self._SCENE.getRenderingContext()
+        currentFrame = context.currentFrame()
 
-        Parameters:
-        scene --- the Blender Scene to render
-        cameraObj --- the camera object to use for the viewing processing
-        """
+        # 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
+
+        print "Done!"
+        context.currentFrame(currentFrame)
 
-        if cameraObj == None:
-            cameraObj = scene.getCurrentCamera()
+
+
+    def doRenderScene(self, inputScene):
+        """Control the rendering process.
         
-        context = scene.getRenderingContext()
-        self.canvasSize = (context.imageSizeX(), context.imageSizeY())
+        Here we control the entire rendering process invoking the operation
+        needed to transform and project the 3D scene in two dimensions.
+        """
         
-        Objects = scene.getChildren()
+        # 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.camera, self.canvasRatio)
+            
+        # global processing of the scene
+        self._doDepthSorting(workScene)
         
-        # A structure to store the transformed scene
-        newscene = []
+        # Per object activities
+        Objects = workScene.getChildren()
         
         for obj in Objects:
             
-            if (obj.getType() != "Mesh"):
+            if (obj.getType() != 'Mesh'):
                 print "Type:", obj.getType(), "\tSorry, only mesh Object supported!"
                 continue
+            #
+
+            self._doModelViewTransformations(obj)
+
+            self._doBackFaceCulling(obj)
+            
+            self._doColorAndLighting(obj)
+
+            # 'style' can be a function that determine
+            # if an edge should be showed?
+            self._doEdgesStyle(obj, style=None)
+           
+            self._doProjection(obj, proj)
+
+        return workScene
+
 
+    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(cameraObj, obj, self.canvasSize)
+            proj = Projector(self.camera, obj, self.canvasSize)
 
             # Let's store the transformed data
-            transformed_mesh = NMesh.New(obj.name)
+            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()
 
@@ -415,23 +540,30 @@ class Renderer:
                 if self._isFaceVisible(face, obj, cameraObj):
                     
                     # Store transformed face
-                    transformed_face = []
+                    newface = NMesh.Face()
 
                     for vert in face:
 
                         p = proj.doProjection(vert.co)
 
-                        transformed_vert = NMesh.Vert(p[0], p[1], p[2])
-                        transformed_face.append(transformed_vert)
+                        tmp_vert = NMesh.Vert(p[0], p[1], p[2])
 
-                    newface = NMesh.Face(transformed_face)
+                        # 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 = -250
-                    fakelight = [10, 10, 15]
-                    norm = face.normal
+                    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
@@ -439,88 +571,203 @@ class Renderer:
                         intensity = 0
 
                     if materials:
-                        newface.col = materials[face.mat].getRGBCol()
+                        tmp_col = materials[face.mat].getRGBCol()
                     else:
-                        newface.col = [0.5, 0.5, 0.5]
+                        tmp_col = [0.5, 0.5, 0.5]
                         
-                    newface.col = [ (c>0) and (c-intensity) for c in newface.col]
+                    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_object = NMesh.PutRaw(transformed_mesh)
-            newscene.append(transformed_mesh)
+            transformed_obj = Object.New(obj.getType(), "flat"+obj.name)
+            transformed_obj.link(transformed_mesh)
+            transformed_obj.loc = obj.loc
+            newscene.link(transformed_obj)
 
-        # reverse the order (TODO: See how is the object order in NMesh)
-        #newscene.reverse()
         
-        return newscene
+        return workScene
 
 
     ##
     # Private Methods
     #
 
-    def _isFaceVisible(self, face, obj, cameraObj):
-        """Determine if the face is visible from the current camera.
+    # Faces methods
 
-        The following code is taken basicly from the original vrm script.
+    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.
+
+        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
+        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.
+
+        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.
         """
 
-        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 = Vector([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(norm, Vector(a))
-
-        return (d<0)
-
-    def _doClipping(face):
+        # The transformation matrix of the object
+        mObj = Matrix(obj.getMatrix())
+        mObj.transpose()
+
+        # The normal after applying the current object rotation
+        #normal = mObj.rotationPart() * Vector(face.no)
+        normal = Vector(face.no)
+
+        # 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
+
+
+    # Scene methods
+
+    def _doClipping():
+        return
+
+    def _doDepthSorting(self, scene):
+
+        cameraObj = self.camera
+        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:
+
+            if (o.getType() != 'Mesh'):
+                continue
+            #
+
+            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
+
+    def _doModelViewTransformations(self, object):
+        if(object.getType() != 'Mesh'):
+            return
+        
+        matMV = object.matrix
+        mesh = object.data
+        mesh.transform(matMV, True)
+        mesh.update()
+
+
+    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
+
+        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
+
+        mesh.update()
+
+        
+
+        #Mesh.Mode(Mesh.SelectModes['VERTEX'])
+
+    def _doColorAndLighting(self, object):
         return
 
+    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).
+
+        input: an edge list
+        return: a processed edge list
+        """
+        return
+
+    def _doProjection(self, object, projector):
+
+        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()
+
+
 
 # ---------------------------------------------------------------------
 #
@@ -529,42 +776,42 @@ class Renderer:
 # ---------------------------------------------------------------------
 
 
-# hackish sorting of faces according to the max z value of a vertex
-def zSorting(scene):
-    for o in scene:
-        o.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)))
-        o.faces.reverse()
+# FIXME: really hackish code, just to test if the other parts work
     
-from Blender import sys
 def vectorize(filename):
-
-    print "Filename: %s" % filename
-    print
-    filename = filename.replace('/', sys.sep)
-    print filename
-    print
+    """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()
     
-    scene   = Scene.GetCurrent()
     renderer = Renderer()
+    renderer.doRendering(writer)
 
-    flatScene = renderer.doRendering(scene)
-    canvasSize = renderer.getCanvasSize()
+    writer.close()
+
+
+# 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)
+
+        vectorize("proba.svg")
+        if editmode: Window.EditMode(1) 
 
-    zSorting(flatScene)
 
-    writer = SVGVectorWriter(filename, canvasSize)
-    writer.printCanvas(flatScene)
-    
-try:
-    Blender.Window.FileSelector (vectorize, 'Save SVG', "proba.svg")
-except:
-    vectorize("proba.svg")