I am having a problem trying to render a PNG sequence much in the manner you described. This is how I want to do it for exactly the reasons you mentioned (ability to tweak individual emitters, etc, after re-importing to the NLE). However, my alpha PNGs come back very ‘dirty’ looking in Sony Vegas. The edges are darker and blotchy. Doesn’t seem as transparent. How do I get it to retain it’s original clarity over the footage? If I render from PI and leave the background intact, the final looks great. If I hide the background, and try to do a PNG with alpha, it doesn’t look right when I re-insert over the same footage in Vegas. What am I missing? Any ideas?
Thanks–PW