I’m making a composite of live-action and CG, and my CG dragon has to move behind some of the trees and characters. I can do that easily by having “mask” objects over the dragon and making their alpha set to zero so they reflect the video which is the background.
My only problem is I’m using vector blur, and those little mask objects move around a whole lot. So the video looks sweet, except there are random blurs here and there when the vector objects moved too fast!
Is there a way to only vector blur certain parts of a scene?
I can’t figure out how to get it to work. I need the background behind the dragon, the masks in front of the dragon, and the vector blur on only the dragon.
I tried using two AlphaOver nodes, but that didn’t work. For some reason my masks aren’t showing up.
Never mind, I got it figured out, with the crude method of making my sky background green and my mask objects the same green, then greenscreening the video of the dragon walking in greenland over the actual footage.
Well, that’s one way to do it… What I meant about the render layers was this: You put your background and anything else you want in one layer, and your dragon on another. You associate each of those layers with a different render layer. Then, when you go to the node editor, you can control both layers separately, only applying the vector blur to one of them.
The attached image illustrates how one might set this up.
