add blank material files

gearbox/pbr/cached.wad/cached.wad.mat

@@ -0,0 +1,16 @@
+
+{
+"for" "CONBACK"
+//"basecolor_map" "CONBACK.png"
+//"normal_map" "CONBACK_normal.png"
+//"metal_map" "CONBACK_metal.png"
+//"roughness_map" "CONBACK_roughness.png"
+}
+
+{
+"for" "LOADING"
+//"basecolor_map" "LOADING.png"
+//"normal_map" "LOADING_normal.png"
+//"metal_map" "LOADING_metal.png"
+//"roughness_map" "LOADING_roughness.png"
+}