Masking keyframe on the time line

[Rhoel]

I have found several times recently the need to invert a mask/matte during a scene, and one occassion when I need to have it cut in during a scene.

Though I have mentioned this one before, there are several other bugs/ inconsistancies which would be good to resolve - there is a bug where the preview displays the mask correctly but the rendered output doesn't. Also, if you have nested maskes, the mask this layer/don't mask this layer get completely ignored.

Getting the groupuing to mattes corretly is vital - It is very common for a character to panning but matted to a stationary background. Unfortunately, the way the groups currently work, the BG group matte will not affect the Panning Group matte - you cannot have the matte in the Character group 'cos that's moving.