What if you want to render the background as a separate pass for compositing in Maya using Mental Ray? Well, Ashraf Aiad has a post on how to create a background render pass using Mental Ray for Maya and notes that when you are creating render passes, you notice that the background gets calculated only in the beauty pass, but what if we want the background as a separate pass? Check out how to render a background pass in Maya!

“When rendering your render passes you will notice that the background gets calculated (appear) only in the beauty pass. But what if we want the background as a separate pass for composting purpose. There are some basic methods, for example, A- Adding the IBL in a different layer. Or B- Using a poly sphere with Shader assigned to it, this way the pass will be calculated as according to that Shader. In this tutorial we will look into getting it as a render pass from the IBL node.”