Need suggestions for drawing and erasing effect pls...
 

I want to have an effect of drawing an object and then erasing it.
I have 4 different images, each with a different drawing on it that will seamlessly transition into one another with a solid background that will never change. I was hoping to come up with a way to make it look like the drawing is being made (albeit quickly) with some pen scratching sound effects and then the drawing to look like it is being erased afterwards - and then next drawing will appear and then be erased etc. I have tried a simple effect of transitioning between the layers with a linear wipe that looks ok, but I want to try and make it better. Any ideas or suggestions?

This may not be possible just in Vegas. Especially if you have already tried the linear wipe affect and it is not satisfactory. Have you added a transition blur to help the transition look smoother? What about changing the angle of the linear wipe so that it provides as linear looking of "writing" as possible?

Yet another example of the text manipulation limitations of Vegas.

Have you considered a screen capture of someone using a tablet to draw the picture? You could use software like Camstudio to record an AVI of the desktop of your computer as an artist writes out the text. Then you can crop out the tools & application windows so all that is left is the canvas portion. Then your artist could literally draw the text and erase the text.

Then import the text into Vegas and apply velocity envelopes or the playback rate modifies to speed up / slow down the drawing to match the desired effect. Then you could play the writing backwards for the erasing portion, or you could actually use your graphics app's "eraser" tool and literally erase while CamStudio records video of that. Then repeat the procedure in Vegas for the erasing portion.

Thanks for the idea of the capturing, I will try that.

The new luminance transition in Vegas Pro 9 will let you use grayscale images to determine HOW the the transition occurs. You might want to check it out.

When I've seen this done it was a video or film recording of a hand that was speeded up.

Erasing could be faked but with a lot of work.

Personally I'd skip it, unless your clients requested it and have great flexibility with their budget.

Any low tech means of accomplishing these effects would be cheesy and embarrasing, I'd skip it.

As Jason says you would have to actually record someone doing it to be effective.

I would think you could accomplish this with a lot of keyframing. The mask would steadily spread across the text layer, in the covering or revealing direction. A 2nd video track would hold the psd file of a pencil, which would also include a lot of keyframing for motion.

Here's something I did, recently, involving this kind of motion, although on a much lesser scale...