MultiMatte Renderelement question / Material ID (3dsMax)

[BeneZ]

Hello,

how do I set a material ID?

I selected a material, then went to Compact Editor, where a field is, but the material is not loaded anymore and not visible.
How can I load the material from the slate editor into the Compact editor?

Is the MAT ID also in the Slate Editor?

2.
Is it possible to set a multimatte Renderelemenet also by Layer (everything contained in a layer)?

Thanks

[BeneZ]

Found it now in the Slate editor on the top left...

[^Lele^]

2.
Is it possible to set a multimatte Renderelemenet also by Layer (everything contained in a layer)?

Not directly.
You can however select all the geo on a given layer and assign it a common Object ID.
To do so by material ID gets complicated, as one would have to thrawl through the Layer's shaders (potentially including sub-materials.), and then assign IDs.