To be able to make good masks, it is important to separate the non moving
pixels from the moving ones. With fixes I did 2 weeks ago, a floating
point inaccuracy causes speed vectors to be not always zero perfectly...
and the masks to get badly shaped.
It was clearly visible on moving objects over a non-moving background.
Current commit includes minimal threshold to force speed to zero. Images
are nice and smooth again. :)
Bad:
http://www.blender.org/bf/vb1.jpg
Good again:
http://www.blender.org/bf/vb2.jpg
7c23e08270
