Render Layers - Material Override vs Shader Override

[Anonymous]

I am learning how to use Render Layers in Maya 2022 and have come across the Shader override and the Material override. If I read correctly, the Material is simply the node that contains all the descriptive info/shader network/files that is applied to the geo in the scene. The shader is built into the material and describes the pbr/exclusive attributes contained within the the selected material. However, if you want to say, create and AO render layer - I see in tutorials ( such as in https://www.youtube.com/watch?v=0DxRULTiXDg&t=498s 3:55) you would apply a shader override vs a material override. I'm a bit confused then - I can see how AO could be a shader bc it has specific attributes unique to it - but if it can be directly applied to an object, isn't it equivalent to a material? When do you use a material override vs a shader override?

[Stephen.Blair · Accepted solution]

From the Maya docs:
https://knowledge.autodesk.com/support/maya/learn-explore/caas/CloudHelp/cloudhelp/2020/ENU/Maya-Ren...

Override the material applied to the objects in a collection in one of two ways: create a material override to override the shading group, or a shader override to override the surface shader.

A material override replaces the SG node (the shading engine aka shading group), so a material override replaces the surface shader AND the displacement shader

[Anonymous]

Ah, thank you. I'd completely overlooked the essentials of Shader groups. That clears much up!