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Is there an efficient way of cutting up a circle into even pie slices?

Stuff like this I'd do in Illustrator, or at least prepare a sketch in AI and import it elsewhere.
But don't we have a Polygon tool? Apply it on top level, have a circle on bottom leve, use the corners as guides for straight lines on a third level, use this as stencil to erase on the circle level ... or whatever workflow you prefer.

Thanks, Markus, I have nothing but TVP and Vegas (and want to keep it that way) but your second suggestion sounds just like something I would have likely come up with had no one replied so I'll go for that.

efficient...? not realy i guess.

but you can do it like this:
a lineshaped custombrush in the keyframer, with the length of the circle's radius.
make sure the brush handle is on the endpoint.
create an image layer (not an animlayer!), its length should be one frame more then the number of pie-pieces you need.
in the keyframer make a key for rotation value = 0 on the first frame and value = 1 on the last frame.
Finally apply the effect on all frames of the image layer.(advancing each frame has to be done manually on an image layer... unfortunately)

the number of pie pieces can be easily changed by dragging the last keylayerhandle .

Thanks, Peter. I don't need such precision. Actually in the end I'm going to trace all the lines in freehand to match my drawings, it's going to be that loose.

You wanna know one of my dirty secrets? Sometimes I just paste a piece of cel or tracing paper on my cintiq or use a real world ruler to draw underneath in TVP ...

We are artists and what appears on the screen is a reflection of what we carry inside of us all day long. We still pour our tea from handmade teapots and eat with our hands and lick our plates with our tongues; it's only natural to draw lines with rulers. I'll tell you my dirty little shame; Wacom once came out with a stylus that used a real ballpoint pen for its nib so that you could draw on paper at the same time as you drew into TVP. I had no idea why, but I bought it and it was completely useless.