Sorry if this is an obvious one, but i have searched hi and low.
I am building a scene with a fixed background and lots of 'rotobrushed' vids on top of it.(with masks)
I bring on a layer and rotobrush it and then when i go back to themain video, i can see my rotobrushed video on top. If i slide the bar along though i see the message on screen 'rotobrush propagating' and this takes forever. I assume it is re rotobrushing the videos.
Ideally i want to get the rotobrushing and masks done just right and then render that as a simpl file to be used as a layer with the character and the transparent background. I cant quite work out how to do this. Precompose, pre render, render its all very confusing.
Really grateful to anyone prepared to help me out.
Try looking at this tutorial by my friend John Dickinson
you can freeeze the Rotobrush by hitting the respective button, Y' know?! Still, if that many layers are involved, you might simply consider pre-rendering the RB results to a format that supports transparencies/ Alpha channels. Makes life so much easier and AE won't crawl like a toad overrun by a truck...
Stupid, yes, the freeze button - thats it!!! Didnt see that mentioned anywhere!!!
Just in case i run into prbs, do you know a format that can do transparencies?
i should be ok now though. this is a steep learning curve