fix block

src/Materials/Node/Blocks/PBR/clearCoatBlock.ts

@@ -313,6 +313,9 @@ export class ClearCoatBlock extends NodeMaterialBlock {
                     ambientMonochrome,
                 #endif
             #endif
+            #if defined(CLEARCOAT_BUMP) || defined(TWOSIDEDLIGHTING)
+                gl_FrontFacing ? 1. : -1.,
+            #endif
                 clearcoatOut
             );
         #else