Merge pull request #1977 from KhronosGroup/fix_b104852

Fix bad mesh export

addons/io_scene_gltf2/blender/exp/gltf2_blender_gather_nodes.py

@@ -16,6 +16,7 @@
 import bpy
 from mathutils import Matrix, Quaternion, Vector
 
+from ...io.com.gltf2_io_debug import print_console
 from ...io.com import gltf2_io
 from ...io.com import gltf2_io_extensions
 from ...io.exp.gltf2_io_user_extensions import export_user_extensions
@@ -191,7 +192,9 @@ def __gather_mesh(vnode, blender_object, export_settings):
         return None
 
     # Be sure that object is valid (no NaN for example)
-    blender_object.data.validate()
+    res = blender_object.data.validate()
+    if res is True:
+        print_console("WARNING", "Mesh " + blender_object.data.name + " is not valid, and may be exported wrongly")
 
     modifiers = blender_object.modifiers
     if len(modifiers) == 0:

addons/io_scene_gltf2/blender/exp/gltf2_blender_gather_primitives_extract.py

@@ -367,9 +367,16 @@ def populate_dots_data(self):
     def primitive_split(self):
         # Calculate triangles and sort them into primitives.
 
-        self.blender_mesh.calc_loop_triangles()
-        loop_indices = np.empty(len(self.blender_mesh.loop_triangles) * 3, dtype=np.uint32)
-        self.blender_mesh.loop_triangles.foreach_get('loops', loop_indices)
+        try:
+            self.blender_mesh.calc_loop_triangles()
+            loop_indices = np.empty(len(self.blender_mesh.loop_triangles) * 3, dtype=np.uint32)
+            self.blender_mesh.loop_triangles.foreach_get('loops', loop_indices)
+        except:
+            # For some not valid meshes, we can't get loops without errors
+            # We already displayed a Warning message after validate() check, so here
+            # we can return without a new one
+            self.prim_indices = {}
+            return
 
         self.prim_indices = {}  # maps material index to TRIANGLES-style indices into dots