Noob problem: Rotobrush layer wont render

[larsa85501086]

This is probably some really basic oversight on my part. I've rotobrushed part of a video to get rid of the sky in the background. And set the 'work area' to that part. Apparantly that's a layer. And then there's a composition.

Whenever I try to render the video, it renders the composition instead of the layer and the result is a video with nothing but a black screen and the sound. What am I missing? I figure I somehow have to integrate the rotobrushed layer into the composition? How do I do that? 

Any help would be much appreciated.                                                                           

[larsa85501086]

In the Rendercue window under Output module settings, I choose 'Animation' in 'Format options' and then set the 'Channels' to 'RGB + Alpha'. This is necesary for the tranparant background effect to work. But this doesn't seem to be the issue. My problem is that my composition is nothing but a blank space. And when I start rendering, it renders my blank composition instead of the layer.l

[Mylenium]

You have a misunderstanding. Of course AE will always render the composition, not an isolated layer. Even your limited region doesn't mean anything if you don't crop the comp to it. You may want to read the online help on some of the essentials. The rest we can't really know since you haven't included a screenshot of the comp instead of the layer viewer. My only suspicion would have to be that this is simply due to the many issues with Quicktime being kind of broken, so in the render settings try another CoDec like ProRes or DNxHD or an image sequence. Otherwise it could be a million things from specific hardware acceleration issues to the RB cache not being built correctly, but this would really require more info.

Mylenium

[larsa85501086]

Thankyou for the reply. 

1. Could you explain what you mean by the phrase: "...don't crop the comp to it..."

2. What online help essentials would you recommend I read specifically? Can you please provide a link.

3. I've tried rendering it to an(in?) AVI movie, since it's one of the few formts that allow me to choose RGB + Alpha. No succes here either.

4. I tried the ProRes codecs that allowed me to choose RGB + Alpha. And then I tried the DNxHD and the PNG image sequence. None of it worked.

5. The two images is an attempt to show you the composition. I'm not sure how to show to do it though. If you can, please tell me how to do so.

6. What is the RB cache?

Please let me know how to provide you with additional info.

Thanks