Assign a Shader At Render Time in Maya

Often when you work in Maya with shaders, you want to see something that’s different from what you want to render. You might want to see a UV checker pattern to check for texture stretching as you work but still render the object with an SSS shader. What I do in these cases is use a pre-Render MEL script to assign the render shader at render time and then reassign the checker texture right after the render finishes with the Post-Render MEL. These settings are found in the MEL/Python callbacks of the render Settings dialog. Here’s a quick example with two different shaders being swapped at Render time:

Pre-Render MEL code:

select -r pCube1; hyperShade -assign layeredShader1 pCubeShape1;

Post-Render MEL code:

select -r pCube1; hyperShade -assign lambert2 pCubeShape1;