add blank material files

valve/pbr/halflife.wad/+BUTTON2/+BUTTON2.mat

@@ -0,0 +1,16 @@
+
+{
+"for" "+0BUTTON2"
+//"basecolor_map" "+0BUTTON2.png"
+//"normal_map" "+0BUTTON2_normal.png"
+//"metal_map" "+0BUTTON2_metal.png"
+//"roughness_map" "+0BUTTON2_roughness.png"
+}
+
+{
+"for" "+ABUTTON2"
+//"basecolor_map" "+ABUTTON2.png"
+//"normal_map" "+ABUTTON2_normal.png"
+//"metal_map" "+ABUTTON2_metal.png"
+//"roughness_map" "+ABUTTON2_roughness.png"
+}