Ability to load live 3D view into mask editor

Sometimes when I'm making animated titles, I would like to be able to use 2D masks for compositing, but there is no way to draw 2D masks using the 3D camera.

Currently, there are only 2 ways to accomplish this:

• Use 3D geometry to mask things out. Lose ability for custom feathering and flexibility in animating mask shape.
• Render out the viewport, load it back in as a videoclip, then make the mask. If you change anything in the 3D view, all 3 of these steps need to be done over again, instead of just the last one.

It would be nice if by the clip selector, there was a little checkbox that just said "Use 3D View," and loaded in the active camera.