From 5d9f2ed27a5b77f39a825c786a3afdfc61b7f643 Mon Sep 17 00:00:00 2001
From: sercero <ghojea@gmail.com>
Date: Wed, 5 May 2021 23:09:23 -0300
Subject: [PATCH] Fix for Error when Exporting a Shape Key's Normals (#56)

---
 README.md            |  1 +
 io_ogre/ogre/mesh.py | 45 ++++++++++++++++++++++++++++++++------------
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/README.md b/README.md
index 393ab85..23aaa03 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@
 	- [External OGRE Materials](#external-ogre-materials)
 	- [Console Export](#console-export)
 	- [Exporting Custom Vertex Groups](#exporting-custom-vertex-groups)
+	- [Exporting Skeletal Animations](#exporting-skeletal-animations)
 	- [Exporting Particle Systems](#exporting-particle-systems)
 	- [Exporting Shape (or Pose) Animations](#exporting-shape-animations)
 	- [Exporting Node Animations](#exporting-node-animations)
diff --git a/io_ogre/ogre/mesh.py b/io_ogre/ogre/mesh.py
index d33f25d..f264c31 100644
--- a/io_ogre/ogre/mesh.py
+++ b/io_ogre/ogre/mesh.py
@@ -110,7 +110,7 @@ def dot_mesh( ob, path, force_name=None, ignore_shape_animation=False, normals=T
         doc = SimpleSaxWriter(f, 'mesh', {})
 
         # Very ugly, have to replace number of vertices later
-        doc.start_tag('sharedgeometry ', {'vertexcount' : '__TO_BE_REPLACED_VERTEX_COUNT__'})
+        doc.start_tag('sharedgeometry', {'vertexcount' : '__TO_BE_REPLACED_VERTEX_COUNT__'})
 
         logger.info('* Writing shared geometry')
 
@@ -160,6 +160,7 @@ def dot_mesh( ob, path, force_name=None, ignore_shape_animation=False, normals=T
         _remap_verts_ = []
         _remap_normals_ = []
         _face_indices_ = []
+
         numverts = 0
 
         # Create bmesh to help obtain custom vertex normals
@@ -172,8 +173,17 @@ def dot_mesh( ob, path, force_name=None, ignore_shape_animation=False, normals=T
             bm.from_mesh(mesh)
 
         # Ogre only supports triangles
-        bmesh.ops.triangulate(bm, faces=bm.faces)
+        bmesh_return = bmesh.ops.triangulate(bm, faces=bm.faces)
         bm.to_mesh(mesh)
+        
+        # Map the original face indices to the tesselated ones
+        face_map = bmesh_return['face_map']
+        
+        _tess_polygon_face_map_ = {}
+        
+        for tess_face in face_map:
+            #print("tess_face.index : %s <---> polygon_face.index : %s" % (tess_face.index, face_map[tess_face].index))
+            _tess_polygon_face_map_[tess_face.index] = face_map[tess_face].index
 
         # Vertex colors
         vertex_color_lookup = VertexColorLookup(mesh)
@@ -181,9 +191,11 @@ def dot_mesh( ob, path, force_name=None, ignore_shape_animation=False, normals=T
         if tangents:
             mesh.calc_tangents(uvmap=mesh.uv_layers.active.name)
 
-        progressScale = 1.0 / (len(mesh.polygons) - 1)
+        progressScale = 1.0 / len(mesh.polygons)
+        
+        # Process mesh after triangulation
         for F in mesh.polygons:
-            percent = F.index * progressScale
+            percent = (F.index + 1) * progressScale
             sys.stdout.write( "\r + Faces [" + '=' * int(percent * 50) + '>' + '.' * int(50 - percent * 50) + "] " + str(int(percent * 10000) / 100.0) + "%   ")
             sys.stdout.flush()
             
@@ -222,9 +234,7 @@ def dot_mesh( ob, path, force_name=None, ignore_shape_animation=False, normals=T
                 vert_uvs = []
                 if dotextures:
                     for layer in mesh.uv_layers:
-                        vert_uvs.append(layer.data[loop_idx].uv)
-                    """for layer in uvtris[ tidx ]:
-                        vert_uvs.append(layer[ vidx ])"""
+                        vert_uvs.append( layer.data[ loop_idx ].uv )
 
                 ''' Check if we already exported that vertex with same normal, do not export in that case,
                     (flat shading in blender seems to work with face normals, so we copy each flat face'
@@ -257,8 +267,13 @@ def dot_mesh( ob, path, force_name=None, ignore_shape_animation=False, normals=T
                 numverts += 1
                 _remap_verts_.append( v )
                 _remap_normals_.append( n )
-                _face_indices_.append( F.index )
-
+                
+                # Use mapping from tesselated face to polygon face if the mapping exists
+                if F.index in _tess_polygon_face_map_:
+                    _face_indices_.append( _tess_polygon_face_map_[F.index] )
+                else:
+                    _face_indices_.append( F.index )
+                
                 x,y,z = swap(v.co)        # xz-y is correct!
 
                 doc.start_tag('vertex', {})
@@ -592,12 +607,18 @@ def duplicate_object(scene, name, copyobj):
 
                     if config.get('SHAPE_NORMALS'):
                         n = _remap_normals_[ vidx ]
+
                         if smooth:
-                            pn = mathutils.Vector( [snormals[ v.index * 3 ], snormals[ v.index * 3 + 1], snormals[ v.index * 3 + 2]] )
+                            pn = mathutils.Vector( [snormals[ v.index * 3 + 0 ], snormals[ v.index * 3 + 1 ], snormals[ v.index * 3 + 2 ]] )
                         else:
                             vindex = _face_indices_[ vidx ]
-                            pn = mathutils.Vector( [snormals[ vindex * 3 ], snormals[ vindex * 3 + 1], snormals[ vindex * 3 + 2]] )
-                        nx,ny,nz = swap( pn - n )
+                            
+                            pn = mathutils.Vector( [snormals[ vindex * 3 + 0 ], snormals[ vindex * 3 + 1 ], snormals[ vindex * 3 + 2 ]] )
+
+                        if mesh.has_custom_normals:
+                            nx,ny,nz = n
+                        else:
+                            nx,ny,nz = swap( pn )
 
                     #for i,p in enumerate( skey.data ):
                     #x,y,z = p.co - ob.data.vertices[i].co