add intermediate array to fix shader index select

Effects/PBREffect.fx

@@ -296,6 +296,11 @@ PixelShader PSArray[8] =
     compile ps_3_0 AlbedoMetallicRoughnessNormalMapPS()
 };
 
+int PSIndices[8] =
+{
+    0, 1, 2, 3, 4, 5, 6, 7
+};
+
 int ShaderIndex = 0;
 
 Technique PBR
@@ -303,6 +308,6 @@ Technique PBR
     Pass
     {
         VertexShader = compile vs_3_0 main_vs();
-        PixelShader = (PSArray[ShaderIndex]);
+        PixelShader = (PSArray[PSIndices[ShaderIndex]]);
     }
 }