workflow for layers for compositing

[caspian]

I've realised that I don't really have an efficient process when it comes to rendering for compositing. I'd like to change that. What I tend to do is render my scene and then render it again with the background with a shadow catcher. Then I use the shadow catcher as a mask to isolate the subject in Photoshop. But this means I have to render everything twice and I've a hunch this isn't the way you all do it. Can anyone share a better process with me.
Thanks

[Beanzvision]

Hi There, are you making use of masks etc to save you re-rendering again? Perhaps this may help?
https://support.corona-renderer.com/hc/en-us/articles/4402484491793-What-multi-pass-channels-are-available-

[caspian]

Nope! Totally missed masks in my learning so far. I'll fire up a previous project and see if I can follow that page. thanks!

[burnin]

there's also Cryptomatte  playground

[caspian]

I've had a go at it. Using masks I can work out how I can seperate the individual objects in my scene. But I can't work out how to include a useful shadow mask (as useful as the shadow catcher is) as well, except by re-rendering with the shadow catcher on the background layer. Can you offer any suggestions? (I realise I can combine an object ID mask with the Shadow from the Multipass in photoshop to re-create a layer/channel that would be the same as the Shadow catcher, but it this really the way to do it?)

[Beanzvision]

Hi, is my example the kind of image you are after as a final render? I still don't think there is a need to render it twice. Perhaps you can share exactly the look you're after?

[BigAl3D]

Here's how I do it. What I like about this setup is that it's just one render and I get a pure selection mask, an RGBa image with the shadow included. You could even have an additional mask with the object and shadow. Whatever you like. I've done other where I have 10 passes, all done with one render and has everything from individual lights (if you set up LightMix), to reflections, bloom and glare, etc.

Don't hesitate to ask more questions.

[caspian]

Thanks for the help so far. I guess what I'm doing is the wrong way, and I should be making the background in Photoshop rather than using the render's background plane and putting a shadow catcher on top. In this instance there is a subtle red tint on the background material that I seem to loose if I just have the background plane as a shadow catcher. I haven't found which (if any) part of the multi pass separates that out for me. Then again it's not a physically accurate scene setup so that's probably my fault.
I have put the file here if you wanted to have a peak, but there isn't much going on in it.

https://www.dropbox.com/s/jh0h2nodgauirs8/champion-1.c4d?dl=0

[BigAl3D]

@caspian Somehow I forget to attach this image. On the right is the MultiPass window. I added a Mask and then dragged my text object (or parent so all objects in that group will get a single mask) into the window and set it to Include Selection. This will provide a clean mask for your text that you can used to place images behind the text, but over or multiplied into the shadows.

[caspian]

I think I understand what I need to do next time. Thanks for your help!

[romullus]

Hi, is my example the kind of image you are after as a final render? I still don't think there is a need to render it twice. Perhaps you can share exactly the look you're after?

Hi Beanz,

Can you say the name of the font, please?

[Beanzvision]

Hi, is my example the kind of image you are after as a final render? I still don't think there is a need to render it twice. Perhaps you can share exactly the look you're after?

Hi Beanz,

Can you say the name of the font, please?

Sure man, it's called Ruler Modern. :) https://www.dafont.com/ruler-modern.font