Render Layer Material Override result is Incomplete / Offset

[Ian.Rich5QFMD]

Hello, 

I am using a render layer material override to give myself a flat color / alpha cutout image for compositing. 

As you can see, one of the objects in the layer has a result that seems to be scaled down. 

This is the same frame rendered with and without the override, layered over each other.. any clues?

Thanks!

[hamsterHamster]

Isn't that something alpha-premultipication related? Like, if you have a black background and semi-transparent alpha (e.g. edge antialiasing), then it could form such black contours. Are those both one layer objects? If different, then all you need is to copy alpha/matte interpretation settings from correct one to not so much one.

For compositing (cut-out) purposes, you don't need color information at all, as you can use alpha as matte. Finally, you can render on red background.

[Ian.Rich5QFMD]

Thanks Hamster,

 That’s a good thought about premultiply, thing is, both these objects are in the same layer, thus are sharing settings...

 That might be a good workaround option though, using a colored background’s alpha for the cutout.