add blank material files

valve/pbr/halflife.wad/-[OUT_RK]/-[OUT_RK].mat

@@ -0,0 +1,12 @@
+include "-OUT_RK3.mat"
+include "-OUT_RK4.mat"
+include "-OUT_RK5.mat"
+include "-OUT_RKPATH.mat"
+
+{
+"for" "OUT_RK3"
+//"basecolor_map" "OUT_RK3.png"
+//"normal_map" "OUT_RK3_normal.png"
+//"metal_map" "OUT_RK3_metal.png"
+//"roughness_map" "OUT_RK3_roughness.png"
+}