Re: Cinema 4D Shadow Pass not rendering in Alpha. by Darby Edelen on May 4, 2012 at 6:28:23 am
[Chris Wood]"Unfortunately, no matter what PNG settings I use, I end up with a black and white image, where really I just want the shadows and literally nothing else (everything else just transparent)"
Looks to me like you could invert that shadow render and use that as alpha for a black layer in photoshop or AE.
Is there a reason you wouldn't want to just multiply this shadow pass into your image though?