Wasn’t quite sure where to post but I was having a bit of an issue, I have been working on a scene and I am trying to render it so only the objects are visible, so when I import into after effects all the grey area in the render will be gone, just like when you make a png image have no background its just the object, I think it has something to do with alpha channels and rendering, but im not sure, I also read about a plugin for blender called AEE which was after effects exporter but the newest documentation I could find said it worked for 2.49 and I use 2.58, So! I was just wondering if anyone could help me out! thanks guys
to render a png with an alpha channel, just set file type to png, and set to RGBA in render buttons. this question really belongs in the lighting and rendering sub-forum a few ticks down btw. no biggie.
Im looking how to do it with video rather then just a png image. Thanks for the reply!
Im looking how to do it with video rather then just a png image.
You will need a video codec that supports an alpha channel, such as Quicktime Animation. Note that QT has been removed from some of the latest blender versions (Search the forums for an explaination as to why)
I would highly recommend rendering an image sequence, it is far more flexible and safer from the effect of any crash during rendering. You can just bring the sequence into AE I’d assume.
Richard is correct – AE supports image sequences. And you can also use AE to convert the image sequence into a movie file if you prefer. I usually use PNG sequences, 100% compression, with RGBA enabled (for the file name use something like “myRender_####.png” – the “####” will turn into “0001” “0002” “0003” etc).
As for exporting from Blender to AE, you’d want Bartek Skorupa’s Blender to AE exporter. Keep in mind that this doesn’t actually export the models; rather you can export a camera as well as a bunch of nulls that will correspond with elements in your scene. This allows you to create graphics in AE that will correspond with your Blender render. Good luck!
Awesome the png sequence worked perfectly and adobe automatically took out the alpha channels 
thanks guys, I have another unrelated question maybe you guys can help with, is there an option somewhere that lets blender pick a random material when making a particle? Im making a explosion of bouncy balls and im only using about 15 particles over 5 seconds, but Im wondering if blender has any sort of random material picker so the balls are different color each time! thanks again for the image sequence 
i don’t think so but you can animate materials, so you could have the color of the emmitor be a different color for every frame, but it wouldn’t be random. just type I in the material window to set a keyframe.
Okay well if it is impossible to have random colors since Im only doing 15 of them I could always custom do them, but how would I get a force/explosion that would effect 15 individual objects, only way I really know how to do any real physics is particle emitter.
well, if you were using 2.49, i’d say give it a magic texture and animate the z offset, but we don’t have the magic texture in 2.5