Merge pull request #11802 from manthrax/blender-exporter-multi-materials

Fix export for multiple materials per mesh.

utils/exporters/blender/addons/io_three/exporter/api/object.py

@@ -98,11 +98,12 @@ def cast_shadow(obj):
             ret = None
         return ret
     elif obj.type == MESH:
-        mat = material(obj)
-        if mat:
-            return data.materials[mat].use_cast_shadows
-        else:
-            return False
+        mats = material(obj)
+        if mats:
+            for m in mats:
+                if data.materials[m].use_cast_shadows:
+                    return True
+        return False
 
 
 @_object
@@ -127,8 +128,10 @@ def material(obj):
 
     """
     logger.debug('object.material(%s)', obj)
+
     try:
-        return obj.material_slots[0].name
+        matName = obj.material_slots[0].name # manthrax: Make this throw an error on an empty material array, resulting in non-material
+        return [o.name for o in obj.material_slots]
     except IndexError:
         pass
 
@@ -361,13 +364,15 @@ def receive_shadow(obj):
 
     """
     if obj.type == MESH:
-        mat = material(obj)
-        if mat:
-            return data.materials[mat].use_shadows
-        else:
-            return False
+        mats = material(obj)
+        if mats:
+            for m in mats:
+                if data.materials[m].use_shadows:
+                    return True
+        return False
 
-AXIS_CONVERSION = axis_conversion(to_forward='Z', to_up='Y').to_4x4()
+# manthrax: TODO: Would like to evaluate wether this axis conversion stuff is still neccesary AXIS_CONVERSION = mathutils.Matrix()
+AXIS_CONVERSION = axis_conversion(to_forward='Z', to_up='Y').to_4x4() 
 
 @_object
 def matrix(obj, options):

utils/exporters/blender/addons/io_three/exporter/object.py

@@ -90,13 +90,21 @@ class Object(base_classes.BaseNode):
 
         if self.options.get(constants.MATERIALS):
             logger.info("Parsing materials for %s", self.node)
-            material_name = api.object.material(self.node)
-            if material_name:
-                logger.info("Material found %s", material_name)
-                material_inst = self.scene.material(material_name)
-                self[constants.MATERIAL] = material_inst[constants.UUID]
+
+
+            material_names = api.object.material(self.node) #manthrax: changes for multimaterial start here
+            if material_names:
+                logger.info("Got material names for this object:",material_names);
+                materialArray = [self.scene.material(objname)[constants.UUID] for objname in material_names]
+                if len(materialArray) == 0:  # If no materials.. dont export a material entry
+                    materialArray = None
+                elif len(materialArray) == 1: # If only one material, export material UUID singly, not as array
+                    materialArray = materialArray[0]
+                # else export array of material uuids
+                self[constants.MATERIAL] = materialArray
+                logger.info("materials:",self[constants.MATERIAL]);
             else:
-                logger.info("%s has no materials", self.node)
+                logger.info("%s has no materials", self.node) #manthrax: end multimaterial
 
         # TODO (abelnation): handle Area lights
         casts_shadow = (constants.MESH,