From c2b5834e233a505910047e9c80070853b40091d3 Mon Sep 17 00:00:00 2001
From: Mikko Rasa <tdb@tdb.fi>
Date: Sat, 4 May 2019 16:39:26 +0300
Subject: [PATCH] Fix some errors introduced in the refactoring

---
 blender/io_mspgl/mesh.py | 31 +++++++++++++++++++++++--------
 1 file changed, 23 insertions(+), 8 deletions(-)

diff --git a/blender/io_mspgl/mesh.py b/blender/io_mspgl/mesh.py
index 62d75063..a303db99 100644
--- a/blender/io_mspgl/mesh.py
+++ b/blender/io_mspgl/mesh.py
@@ -99,6 +99,10 @@ class Face:
 			return 1
 		return cmp(self.index, other.index)
 
+	def pivot_vertex(self, v):
+		n = self.vertices.index(v)
+		return [(n+i)%len(self.vertices) for i in range(len(self.vertices))]
+
 	def pivot_vertices(self, *vt):
 		flags = [(v in vt) for v in self.vertices]
 		l = len(self.vertices)
@@ -170,9 +174,9 @@ class Mesh:
 		self.loops = self.loops[:]
 
 		self.materials = self.materials[:]
-		if self.use_uv=='NONE':
+		if self.use_uv=='NONE' or not self.uv_layers:
 			self.uv_layers = []
-		elif self.uv_layers:
+		else:
 			self.uv_layers = [UvLayer(u) for u in self.uv_layers]
 			self.uv_layers = sorted([u for u in self.uv_layers if not u.hidden], key=(lambda u: (u.unit or 1000, u.name)))
 
@@ -468,16 +472,16 @@ class Mesh:
 			v.tan = mathutils.Vector()
 			v.bino = mathutils.Vector()
 			for f in v.faces:
-				vi = f.vertices.index(v)
-				uv0 = layer_uvs[f.loop_indices[vi]]
-				uv1 = layer_uvs[f.loop_indices[vi+1]]
-				uv2 = layer_uvs[f.loop_indices[vi-1]]
+				vi = f.pivot_vertex(v)
+				uv0 = layer_uvs[f.loop_indices[vi[0]]]
+				uv1 = layer_uvs[f.loop_indices[vi[1]]]
+				uv2 = layer_uvs[f.loop_indices[vi[-1]]]
 				du1 = uv1[0]-uv0[0]
 				du2 = uv2[0]-uv0[0]
 				dv1 = uv1[1]-uv0[1]
 				dv2 = uv2[1]-uv0[1]
-				edge1 = f.vertices[vi+1].co-f.vertices[vi].co
-				edge2 = f.vertices[vi-1].co-f.vertices[vi].co
+				edge1 = f.vertices[vi[1]].co-f.vertices[vi[0]].co
+				edge2 = f.vertices[vi[-1]].co-f.vertices[vi[0]].co
 				div = (du1*dv2-du2*dv1)
 				if div:
 					mul = edge1.angle(edge2)/div
@@ -565,6 +569,17 @@ def create_mesh_from_object(context, obj, progress=None):
 	for o, m in objs:
 		bmesh = o.to_mesh(context.scene, True, "PREVIEW")
 		bmeshes.append(bmesh)
+
+		# Object.to_mesh does not copy custom properties
+		bmesh.winding_test = o.data.winding_test
+		bmesh.smoothing = o.data.smoothing
+		bmesh.use_lines = o.data.use_lines
+		bmesh.vertex_groups = o.data.vertex_groups
+		bmesh.max_groups_per_vertex = o.data.max_groups_per_vertex
+		bmesh.use_uv = o.data.use_uv
+		bmesh.tbn_vecs = o.data.tbn_vecs
+		bmesh.tbn_uvtex = o.data.tbn_uvtex
+
 		me = Mesh(bmesh)
 		me.transform(m)
 
-- 
2.45.2