resource: backward compatibility fix

src/resource/physics_resource.cpp

@@ -127,7 +127,8 @@ namespace physics_resource_internal
 		cd.local_tm = MATRIX4X4_IDENTITY;
 		cd.size     = 0;
 		DynamicString source(ta);
-		sjson::parse_string(obj["source"], source);
+		if (json_object::has(obj, "source"))
+			sjson::parse_string(obj["source"], source);
 		bool explicit_collider = source == "mesh" || json_object::has(obj, "scene");
 
 		if (explicit_collider) {
@@ -235,7 +236,6 @@ namespace physics_resource_internal
 			Quaternion rotation = sjson::parse_quaternion(collider_data["rotation"]);
 			Vector3 position = sjson::parse_vector3(collider_data["position"]);
 			Matrix4x4 matrix_local = matrix4x4(rotation, position);
-			matrix_local.t = vector4(position.x, position.y, position.z, 1.0f);
 			cd.local_tm = matrix_local;
 
 			if (cd.type == ColliderType::SPHERE) {