Hello!

I'll caveat this by saying that I'm a Mantra novice – I realize that it's possible that this is totally normal, and I just don't fully understand how mantra generates the combined lighting per-component image plane under the hood.

That said, I've noticed that when I enable Combined Lighting Per-Component while dealing with a large number of packed disk primitives, my render times increase dramatically. In the test scene attached I've got a bunch of pig heads loaded as packed disk primitives copied to points. When I render a frame with combined lighting disabled, I get a render time of 7 seconds; when I enable combined lighting per component I get a render time of 41 seconds. Seems like a BIG jump!

As a separate test I've also got a single pig head loaded normally. When I render that test I get a render time of 7 seconds with combined lighting disabled vs. 10 seconds with it enabled. That variance seems more reasonable.

Anyone have a deeper understanding of why this is happening? Is this normal? Is there something I can do on my end to make that particular image plane creation more efficient?

I'm running houdini Indie 16.5.536 on macOS.

Thanks!