add blank material files

gearbox/pbr/op4ctf.wad/+pcv_unit/+pcv_unit.mat

@@ -0,0 +1,8 @@
+
+{
+"for" "+0pcv_unit"
+//"basecolor_map" "+0pcv_unit.png"
+//"normal_map" "+0pcv_unit_normal.png"
+//"metal_map" "+0pcv_unit_metal.png"
+//"roughness_map" "+0pcv_unit_roughness.png"
+}