My problem is this: I have a shot where the camera rises then drops. On one side of the shot is a wall with siding on it. Vector Blur does not like this. With even the slightest movement, it throws everything out of whack. I’ve tinkered with the minimum speed values, but haven’t gotten very satisfying results.
Is there any way to tell the compositor to avoid that part of the frame? Or, and potentially more beneficial, is there a way to have the motion blur with a very high min speed only affect that area while the rest is blurred by a different node with a lower min speed?
You could try putting the problem object/s on a different renderlayer. Failing that you could opt to render the problem frames with full sample motion blur, and then use vector blur for everything else.
Wow, I just spent about two days rendering an animation with motion blur, and now I find out about vector blur! Thanks guys, you have saved me many future hours!
Yes there is. You can setup 2 vector blur nodes with the different settings. What you need next are 2 masks, one for the area for vector blur setting 1 and one for setting 2. The masks can be created either by using the objectid layer or even doing it by hand and creating a rotomask (quite easy now with the new rotobezier functionality in 2.5.x)
You can now mix the original footage with the vector blur passes outputs by using the masks as factor input to the mix nodes.
Thanks! I’m pretty new to the compositor, though, so I have no idea how to do masks, or a rotomask/bezier, so I’m kind of lost. Are there any good tutorials out there that can help?