Hi Paul,
Sorry i realised id posted another topic in relation to this so deleted and added back in here - this follows on from an old post.
To recap my earlier message:
I was wondering how to enable an octane material to not only catch shadows but also secondary bounced light and colour from HDRI’s etc for compositing. Currently enabling the shadow catcher in a diffuse material does sort of work but it only seems to produce a ‘black’ shadow and not the subtle bounced colour, more of a direct shadow if that makes any sense. I’m pretty sure I used to use a ‘matte shadow material’ in mental ray years ago that would essentially catch everything on its surface that was direct & indirect. Is there something I need to tick on etc? This tutorial (
https://www.youtube.com/watch?v=mST_-dmZYHc) in C4D relates as he adds a diffuse material and set it to 'matte' - this is what i woudl have done in MR essentially.
For example on this sample scene there is a white background with a red ball lit by an HDRI. The shadows are soft, subtle red colour bounce etc etc.
I then change the background to diffuse material, switch on shadow catcher and enable alpha channel in the kernel settings.
The render show a stark dark shadow, no subtle subtle bounced colour etc but does contain transparency
Is there a workflow for a simple matte material that can catch the shadows & other subtle Illumination on the background, or is the workflow to use render passes? if so, how do i enable the alpha for the layers? I may be getting muddled up with the shadow catcher setting & render passes - guidance appreciated!
Cheers
Will.