Shadow catcher pass counting

[Juraj]

I am not 100perc. sure this is a bug, but I wonder why it behaves this way.

I use shadow catcher to get shadows on ground plane (and what is the perfect way to achieve just that ? No light alteration on scene), and the moment I use something else in the color slot, like HDRi, the pass counting starts going about 100 times faster, but noise seems to calculate the same.

[maru]

I use shadow catcher to get shadows on ground plane (and what is the perfect way to achieve just that ? No light alteration on scene)

What kind of light alteration do you mean? Shadowcatcher altering the scene lighting in some way?

the moment I use something else in the color slot, like HDRi, the pass counting starts going about 100 times faster, but noise seems to calculate the same.

I couldn't reproduce this. Can you give more hints how to do it, or a sample scene?

[Juraj]

I use shadow catcher to get shadows on ground plane (and what is the perfect way to achieve just that ? No light alteration on scene)

What kind of light alteration do you mean? Shadowcatcher altering the scene lighting in some way?

Yes of course. Let's say I put CoronaColor into EnviroBackplate, and that is what will affect the light depending on it's intensity. Also reflection. But maybe I just don't understand this material...

Well, I can just send you the scene I guess.

[Juraj]

Ok funny, now I see why I didn't understand the projection, it doesn't work with VrayHDRi :- D

The moment I put CoronaBitmap, all 3 modes behaved as I would expect them. Still, the pass counting differs nonetheless, doesn't seem like bug but it's strange behaviour.

I guess the other issue is the material forcing you to have black background when "compositing" is selected. I would like to directly select what I want, or atleast what is visible in Override directly visible in Render settings.
This step forces you to do in in post.