Blender exporter: Generate correct normals for smooth vertices

[libs/gl.git] / mesh_export.py

diff --git a/mesh_export.py b/mesh_export.py
index cdab35f3486b4dcb00ec1b0014d617235908030a..0158bdbf9189d3cff6e2bedae25b8e040601d02b 100644 (file)
--- a/mesh_export.py
+++ b/mesh_export.py
@@ -9,6 +9,7 @@ Group: 'Export'
 
 import sys
 import math
+import bpy
 import Blender
 
 class Edge:
@@ -60,19 +61,13 @@ class Face:
        def __getattr__(self, attr):
                return getattr(self._mface, attr)
 
-       def get_following_vertex(self, *vt):
-               seen=False
-               indices=[v.index for v in vt]
-               for v in self.verts:
-                       if v.index in indices:
-                               seen=True
-                       elif seen:
-                               return v
-
-               if seen:
-                       return self.verts[0]
-
-               return None
+       def get_vertices_from(self, *vt):
+               indices=[u.index for u in vt]
+               flags=[(v.index in indices) for v in self.verts]
+               l=len(self.verts)
+               for i in range(l):
+                       if flags[i] and not flags[(i+l-1)%l]:
+                               return self.verts[i:]+self.verts[:i]
 
 
 class SmoothGroup:
@@ -88,13 +83,16 @@ class SmoothGroup:
                                v=f.verts[i]
                                if v.index not in vert_map:
                                        vt=Vertex(v)
-                                       if not f.smooth:
-                                               vt.no=f.no
+                                       vt.no=Blender.Mathutils.Vector(f.no)
                                        self.verts.append(vt)
                                        vert_map[v.index]=vt
                                        f.verts[i]=vt
                                else:
                                        f.verts[i]=vert_map[v.index]
+                                       vert_map[v.index].no+=f.no
+
+               for v in self.verts:
+                       v.no.normalize()
 
 
 class Exporter:
@@ -106,6 +104,7 @@ class Exporter:
                        self.out_file=file(fn, "w")
                self.use_strips=True
                self.use_degen_tris=True
+               self.debug=False
 
        def find_smooth_group(self, face, sg):
                face.smooth_group=sg
@@ -132,18 +131,24 @@ class Exporter:
                if not edge:
                        return None
 
-               v1=face.get_following_vertex(edge.v1, edge.v2)
-               v2=face.get_following_vertex(v1)
-               if len(face.verts)==4:
-                       result=[v2, v1]
-               else:
-                       result=[v1, v2]
+               if self.debug:
+                       print "Starting strip from %s"%[v.index for v in face.verts]
+
+               verts=face.get_vertices_from(edge.v1, edge.v2)
+               result=[verts[-2], verts[-1]]
 
                while 1:
+                       verts=face.get_vertices_from(*result[-2:])
+                       k=len(result)%2
+                       if self.debug:
+                               print "  %d %s"%(len(result), [v.index for v in verts])
+
                        face.flag=True
-                       for i in range(2, len(face.verts)):
-                               v=face.get_following_vertex(result[-2], result[-1])
-                               result.append(v)
+                       if len(verts)==4 and not k:
+                               result.append(verts[3])
+                       result.append(verts[2])
+                       if len(verts)==4 and k:
+                               result.append(verts[3])
 
                        i1=result[-2].index
                        i2=result[-1].index
@@ -154,16 +159,19 @@ class Exporter:
                                        break
 
                        next=edge.other_face(face)
-                       if next.smooth_group.index!=face.smooth_group.index or next.flag:
+                       if not next or next.smooth_group.index!=face.smooth_group.index or next.flag:
                                break
                        face=next
 
+               if self.debug:
+                       print "  %s"%[v.index for v in result]
+
                return result
 
        def export(self):
-               scene=Blender.Scene.GetCurrent()
+               scene=bpy.data.scenes.active
 
-               obj=scene.getActiveObject()
+               obj=scene.objects.active
                if obj.getType()!="Mesh":
                        raise Exception, "Can only export Mesh data"
 
@@ -181,6 +189,9 @@ class Exporter:
                for e in edges.itervalues():
                        e.check_smooth(smooth_limit)
 
+               if self.debug:
+                       print "%d faces, %d edges"%(len(faces), len(edges))
+
                smooth_groups=[]
                for f in faces:
                        if not f.smooth_group:
@@ -191,6 +202,12 @@ class Exporter:
                for sg in smooth_groups:
                        sg.find_vertices()
 
+               if self.debug:
+                       print "%d smooth groups:"
+                       for i in range(len(smooth_groups)):
+                               sg=smooth_groups[i]
+                               print "  %d: %d faces, %d vertices"%(i, len(sg.faces), len(sg.verts))
+
                strips=[]
                if self.use_strips:
                        for sg in smooth_groups:
@@ -225,8 +242,11 @@ class Exporter:
                                verts.append(v)
 
                self.out_file.write("vertices NORMAL3_VERTEX3\n{\n")
+               norm=None
                for v in verts:
-                       self.out_file.write("\tnormal3 %f %f %f;\n"%tuple(v.no))
+                       if v.no!=norm:
+                               self.out_file.write("\tnormal3 %f %f %f;\n"%tuple(v.no))
+                               norm=v.no
                        self.out_file.write("\tvertex3 %f %f %f;\n"%tuple(v.co))
                self.out_file.write("};\n")
                for s in strips:
@@ -258,6 +278,7 @@ class FrontEnd:
 
        def export(self, fn):
                exp=Exporter(fn)
+               #exp.use_degen_tris=False
                exp.export()