+ 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 that will be used to output the result.
+ - a flag to tell if we want to render an animation or only the
+ current frame.
+ """
+
+ context = self._SCENE.getRenderingContext()
+ 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)
+
+ # global processing of the scene
+
+ self._doConvertGeometricObjToMesh(workScene)
+
+ self._doSceneClipping(workScene)
+
+ # FIXME: does not work in batch mode!
+ #if OPTIMIZE_FOR_SPACE:
+ # self._joinMeshObjectsInScene(workScene)
+
+ self._doSceneDepthSorting(workScene)
+
+ # Per object activities
+
+ Objects = workScene.getChildren()
+ for obj in Objects:
+
+ if obj.getType() != 'Mesh':
+ print "Only Mesh 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 _getObjPosition(self, obj):
+ """Return the obj position in World coordinates.
+ """
+ return obj.matrix.translationPart()
+
+ def _cameraViewDirection(self):
+ """Get the View Direction form the camera matrix.
+ """
+ return Vector(self.cameraObj.matrix[2]).resize3D()
+
+
+ # Faces methods
+
+ def _isFaceVisible(self, face):
+ """Determine if a face of an object is visible from the current camera.
+
+ The view vector is calculated from the camera location and one of the
+ vertices of the face (expressed in World coordinates, after applying
+ modelview transformations).
+
+ After those transformations we determine if a face is visible by
+ computing the angle between the face normal and the view vector, this
+ angle has to be between -90 and 90 degrees for the face to be visible.
+ This corresponds somehow to the dot product between the two, if it
+ results > 0 then the face is visible.
+
+ There is no need to normalize those vectors since we are only interested in
+ the sign of the cross product and not in the product value.
+
+ NOTE: here we assume the face vertices are in WorldCoordinates, so
+ please transform the object _before_ doing the test.
+ """
+
+ normal = Vector(face.no)
+ camPos = self._getObjPosition(self.cameraObj)
+ view_vect = None
+
+ # View Vector in orthographics projections is the view Direction of
+ # the camera
+ if self.cameraObj.data.getType() == 1:
+ view_vect = self._cameraViewDirection()
+
+ # View vector in perspective projections can be considered as
+ # the difference between the camera position and one point of
+ # the face, we choose the farthest point from the camera.
+ if self.cameraObj.data.getType() == 0:
+ vv = max( [ ((camPos - Vector(v.co)).length, (camPos - Vector(v.co))) for v in face] )
+ view_vect = vv[1]
+
+ # if d > 0 the face is visible from the camera
+ d = view_vect * normal
+
+ if d > 0:
+ return True
+ else:
+ return False
+
+
+ # Scene methods
+
+ def _doConvertGeometricObjToMesh(self, scene):
+ """Convert all "geometric" objects to mesh ones.
+ """
+ geometricObjTypes = ['Mesh', 'Surf', 'Curve', 'Text']
+
+ Objects = scene.getChildren()
+ objList = [ o for o in Objects if o.getType() in geometricObjTypes ]
+ for obj in objList:
+ old_obj = obj
+ obj = self._convertToRawMeshObj(obj)
+ scene.link(obj)
+ scene.unlink(old_obj)
+
+ # Mesh Cleanup
+ me = obj.getData(mesh=1)
+ for f in me.faces: f.sel = 1;
+ for v in me.verts: v.sel = 1;
+ me.remDoubles(0)
+ me.triangleToQuad()
+ me.recalcNormals()
+ me.update()
+
+ def _doSceneClipping(self, scene):
+ """Clip objects against the View Frustum.
+
+ For now clip away only objects according to their center position.
+ """
+
+ cpos = self._getObjPosition(self.cameraObj)
+ view_vect = self._cameraViewDirection()
+
+ near = self.cameraObj.data.clipStart
+ far = self.cameraObj.data.clipEnd
+
+ aspect = float(self.canvasRatio[0])/float(self.canvasRatio[1])
+ fovy = atan(0.5/aspect/(self.cameraObj.data.lens/32))
+ fovy = fovy * 360.0/pi
+
+ Objects = scene.getChildren()
+ for o in Objects:
+ if o.getType() != 'Mesh': continue;
+
+ obj_vect = Vector(cpos) - self._getObjPosition(o)
+
+ d = obj_vect*view_vect
+ theta = AngleBetweenVecs(obj_vect, view_vect)
+
+ # if the object is outside the view frustum, clip it away
+ if (d < near) or (d > far) or (theta > fovy):
+ scene.unlink(o)
+
+ def _doSceneDepthSorting(self, scene):
+ """Sort objects in the scene.
+
+ The object sorting is done accordingly to the object centers.
+ """
+
+ c = self._getObjPosition(self.cameraObj)
+
+ by_center_pos = (lambda o1, o2:
+ (o1.getType() == 'Mesh' and o2.getType() == 'Mesh') and
+ cmp((self._getObjPosition(o1) - Vector(c)).length,
+ (self._getObjPosition(o2) - Vector(c)).length)
+ )
+
+ # TODO: implement sorting by bounding box, if obj1.bb is inside obj2.bb,
+ # then ob1 goes farther than obj2, useful when obj2 has holes
+ by_bbox = None
+
+ Objects = scene.getChildren()
+ Objects.sort(by_center_pos)
+
+ # update the scene
+ for o in Objects:
+ scene.unlink(o)
+ scene.link(o)
+
+ def _joinMeshObjectsInScene(self, scene):
+ """Merge all the Mesh Objects in a scene into a single Mesh Object.
+ """
+ mesh = Mesh.New()
+ bigObj = Object.New('Mesh', 'BigOne')
+ bigObj.link(mesh)
+
+ oList = [o for o in scene.getChildren() if o.getType()=='Mesh']
+ bigObj.join(oList)
+ scene.link(bigObj)
+ for o in oList:
+ scene.unlink(o)
+
+ scene.update()
+
+
+ # 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)
+
+ # If the object has no materials set a default material
+ if not me.materials:
+ me.materials = [Material.New()]
+ #for f in me.faces: f.mat = 0
+
+ newObject.setMatrix(object.getMatrix())
+
+ return newObject
+
+ def _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._getObjPosition(self.cameraObj)
+
+ # hackish sorting of faces
+
+ # Sort faces according to the max distance from the camera
+ by_max_vert_dist = (lambda f1, f2:
+ 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 min distance from the camera
+ by_min_vert_dist = (lambda f1, f2:
+ 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 avg distance from the camera
+ by_avg_vert_dist = (lambda f1, f2:
+ 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.sort(by_max_vert_dist)
+ 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 can be displayed even if there are no
+ # faces
+ for v in mesh.verts:
+ v.sel = 1
+
+ Mesh.Mode(Mesh.SelectModes['FACE'])
+ # Loop on faces
+ for f in mesh.faces:
+ f.sel = 0
+ if self._isFaceVisible(f):
+ f.sel = 1
+
+ # Is this the correct way to propagate the face selection info to the
+ # vertices belonging to a face ??
+ # TODO: Using the Mesh module 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._getObjPosition(light_obj)
+ light = light_obj.data
+
+ camPos = self._getObjPosition(self.cameraObj)
+
+ # We do per-face color calculation (FLAT Shading), we can easily turn
+ # to a per-vertex calculation if we want to implement some shading
+ # technique. For an example see:
+ # http://www.miralab.unige.ch/papers/368.pdf
+ for f in mesh.faces:
+ if not f.sel:
+ continue
+
+ mat = None
+ if materials:
+ mat = materials[f.mat]
+
+ # A new default material
+ if mat == None:
+ mat = Material.New('defMat')
+
+ 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.
+
+ Examples of algorithms:
+
+ Contours:
+ given an edge if its adjacent faces have the same normal (that is
+ they are complanar), than deselect it.
+
+ Silhouettes:
+ given an edge if one its adjacent faces is frontfacing and the
+ other is backfacing, than select it, else deselect.
+ """
+ #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)
projects / vrm.git / blobdiff