Fix #17

also lowered resource importer priority, shouldn't be default now that
scene importer has subdivision options.

Author: tefusion

project/addons/godot_subdiv/resource_import_plugin.gd

@@ -26,7 +26,7 @@ func _get_preset_name(i):
 	return "Default"
 
 func _get_priority():
-	return 2
+	return 0
 
 func _get_import_order():
 	return IMPORT_ORDER_SCENE

src/import/topology_data_importer.cpp

@@ -31,7 +31,9 @@ void TopologyDataImporter::_bind_methods() {
 
 TopologyDataImporter::SurfaceVertexArrays::SurfaceVertexArrays(const Array &p_mesh_arrays) {
 	vertex_array = p_mesh_arrays[Mesh::ARRAY_VERTEX];
-	normal_array = p_mesh_arrays[Mesh::ARRAY_NORMAL];
+	if (p_mesh_arrays[Mesh::ARRAY_NORMAL].get_type() == Variant::PACKED_VECTOR3_ARRAY) {
+		normal_array = p_mesh_arrays[Mesh::ARRAY_NORMAL];
+	}
 	index_array = p_mesh_arrays[Mesh::ARRAY_INDEX];
 	if (p_mesh_arrays[Mesh::ARRAY_TEX_UV].get_type() == Variant::PACKED_VECTOR2_ARRAY) {
 		uv_array = p_mesh_arrays[Mesh::ARRAY_TEX_UV];