Fix non OpenGL builds with old projects.

Engine/source/materials/customMaterialDefinition.cpp

@@ -150,6 +150,8 @@ bool CustomMaterial::onAdd()
                getName(), samplerName.c_str(), mShaderDataName.c_str() ));
             Con::errorf(error);
 
+            pos = i;
+
 #if TORQUE_OPENGL
             GFXAssertFatal(0, error);
             continue;

Engine/source/materials/processedCustomMaterial.cpp

@@ -409,14 +409,14 @@ void ProcessedCustomMaterial::setTextureStages( SceneRenderState *state, const S
                if ( !texObject )
                   texObject = GFXTexHandle::ZERO;
 
-               if ( handles->mRTParamsSC[i]->isValid() && texObject )
+               if ( handles->mRTParamsSC[samplerRegister]->isValid() && texObject )
                {
                   const Point3I &targetSz = texObject->getSize();
                   const RectI &targetVp = texTarget->getViewport();
                   Point4F rtParams;
 
                   ScreenSpace::RenderTargetParameters(targetSz, targetVp, rtParams);
-                  shaderConsts->set(handles->mRTParamsSC[i], rtParams);
+                  shaderConsts->set(handles->mRTParamsSC[samplerRegister], rtParams);
                }
               
                GFX->setTexture( samplerRegister, texObject );