I am trying to export a clip from Motion 4 to use in an AE CS3 project. I am exporting with the animation codec to include the alpha channel. In project properties the background is set to transparent. It works for about three seconds and then I see the black Background. Funny thing is when I do it again it messes up in a slightly different spot but eventually the alpha channel is gone around the three second mark. I can't see anything in the composition that would be doing this.
Sounds like a memory issue, either RAM or VRAM. Set render quality to Normal if you have it at Best. Or export out without alpha, then a separate render of a greyscale alpha matte, and combine them with a travel matte in AE.
Freelance Producer/Editor/Motion Graphics Artist
Apple-certified Master Trainer
Author, Motion 4 from Peachpit Press http://www.applemotion.net
No luck turning down the quality, but I found a work around for now. I will try your suggestion with the alpha matte etc when I have a moment, if only to learn how to do it that way. Thanks for the help Mark.