add blank material files

gearbox/pbr/models/snow_tree.mdl/snow_tree.mdl.mat

@@ -0,0 +1,16 @@
+
+{
+"for" "#models/snow_tree/tress_fur.mdl"
+//"basecolor_map" "tress_fur.png"
+//"normal_map" "tress_fur_normal.png"
+//"metal_map" "tress_fur_metal.png"
+//"roughness_map" "tress_fur_roughness.png"
+}
+
+{
+"for" "#models/snow_tree/tress_fur_trunk.mdl"
+//"basecolor_map" "tress_fur_trunk.png"
+//"normal_map" "tress_fur_trunk_normal.png"
+//"metal_map" "tress_fur_trunk_metal.png"
+//"roughness_map" "tress_fur_trunk_roughness.png"
+}