I am working on a Bryce animation (not a single frame snapshot) ... it is a pen (like a writing pen) and it's moving along a plane and moves as if someone is holding the pen and writing. I want to create the ink portion of the act of writing with the pen on the paper. Any ideas how I would accomplish the pen on paper part?

Just a suggestion, but this is how I owuld attempt to do it. First you need a jpg or bmp with the handwritten text on it. Project this (Map it)on to the ground plane or desk or paper or whatever it is you are writing on. Let's say paper ok? Then I would use a 2d plane to mask the paper, the 2d plane of course has to blend exactly with the paper so that you can not tell it is a seperate element..you know...same color texture, precisely positioned etc. Now as the pen is moving across the paper in simulated writing you 'pull' the 2d plane along with it so that the writing is revealed, so when the penpoint is at x the right edge of the 2d plane is also at x, when it is x + 1 so is the right edge of the 2d, and so on. Everything to the left of x is revelaed, to the right it is hidden. hope this helps.

I see where you are going here. I can link the animation of the 2d plane to the pen, so when the pen moves the plane moves. gonna go try it

Another suggestion if you have the time is to animate the writing as a 2d animation and simply apply this to the paper. Then all you have to do is work out the timing of the pen with the animated texture.

Ok, you lost me on the last one

Create a standard avi animation of the text being written out in 2d. You may have to do this by using photoshop or psp to create each frame of the animation. Then once you've created that you can apply the avi as an animated texture to your 3d paper. Match the pen to the timing of your animated texture and you have a pen writing on the sheet of paper. Make more sense?