How to create a background pass – Tutorial

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.
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.

Since we already know that the background gets calculated in beauty, now all we need to create and empty beauty pass.
For this we will need to create a Pass Contribution Map (you can refer to my Render passes tutorial to see How to)
However Maya will ignore any empty PCM and renders them out black.

The trick is to add a dummy object that will be behind the camera. It won’t appear in render but it will force Maya to calculate the PCM

Simply add the only the dummy object in the PCM

Add a new beauty pass (I renamed mine) and assign it to the PCM

Now when you render you will get the background, but still we have the car as a black silhouette.

The fix is very simple; we will need to disable the “hold out “option in the render pass AE.

Now when we render, we will get the background as a separate pass.

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One Response to “How to create a background pass – Tutorial”

  1. Max Says:

    Thank you very much for this tutor.

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