For the Shadowcatcher, things should work the same as in Max, so the tutorials at
list=PLt4UrWcQaAX93-ZhmzZSenIqwX4aqEBOs[/youtube] should apply.
There are some current known issues - for example, a CoronaBitmap shows upside down when used as a backplate in the Shadowcatcher. Also, while looking into your request, I noticed this possible bug (in Max, as well as C4D) for surfaces that are at right angles to the Corona Sun and possibly other light sources -
https://forum.corona-renderer.com/index.php?topic=18087.0If the info here doesn't help, could you share more specifics on what you want to achieve - e.g. compositing done directly in C4D with the end render being the result, or rendering for compositing later in another program, and is that compositing simply a matter of overlaying objects on stills, and so on. Also, some screen grabs of your scene set up and materials would be useful too!
Thanks!
Tom