[Brian Jones] “[CaptainMench] “Also — another point to the manual… rendering out multiple passes… is there a way to render out specific elements into different files or channels? I need to composite each item on it’s own.”
Render Settings/Multi-Pass – add whatever channels you want, render to you favorite format.”
More specifically, you have to give your objects compositing tags and specify an object buffer channel in the tag. Then in multipass you have to add an object buffer pass for each object, indicating the number(s) you assigned in the compositing tag. This will give you a separate alpha for the object which you can use to composite it out in post.