Write On Dude

>There are 2 sets of tools that make this really easy....Prem's Surface
>Effectors, and Worley's Polk Plugins. Both sets are priced under $100.00,
>and both will return your investment nearly immediately.

While Surface Effectors and the (newly released) Poke plugin would both do very nice jobs on a hand-writing effect, it's not the kind of effect the person asked for...

>Can Anyone tell me how to do a write on effect of a moving logo?
>The type in the logo is Script so a straight horizontal wipe doesn't
>work.

He already has a logo object created...probably something pre-approved by a client...something that would be damn near impossible to recreate with a "trail-leaving" plugin.

But here's one way I can think of doing this...(off the top of my head with a good late-night coffee/chocolate buzz going)

You need to create a "reveal" effect that uncovers the script logo a little bit at a time. This needs to be done in two passes...the first pass will generate an image sequence transparency map and the second pass would apply that transparency map in a way that actually reveals the logo.

To create the transparency map, simply load your script logo into the scene, position it in the camera view where it needs to be for the final render, and then create a simple flat disc with bright white surface color and 100% (or more) luminosity. Keyframe the disc's position and size so that it traces the shape of the script logo object...the resulting spline path should match the shape of the script logo as closely as possible.

When the path for the disc is all set up, dissolve out the script logo...turn on motion blur...render one "sample" frame...load that "sample" frame as an Image Sequence...change the Frame Offset for that image sequence to -1...put this image sequence into the Background layer. Now render out this animation, but watch the results very closely...the motion blur and imafe sequence background will leave a trail of your disc "writing" on the screen...some areas will be brighter than other but that will be okay as long as the trail is constant.

One the image sequence is rendered, dissolve out the bright white disc and dissolve your script logo back into the scene. Remove the image sequence from the Background layer and, instead, apply it as a Foreground layer. Activate the Foreground Key option...set the High Clip Color value to 255,255,255 and set the Low Clip Color to anything brighter than black...a dark grey will suffice.

Now render out your animation.

What the Foreground Clip settings do is make the entire image black until the "trail" image sequence starts to Key out the black areas...this will reveal your script logo behind the black Foreground image and, if you've done everything correct (and I haven't forgotten anything) you'll have a nice text reveal effect that uses a "real" postscript-font-generated logo.

This is only one of many ways to create this effect, but I don't think I've ever seen this particular approach suggested before. Give it a try and let me know if it's what you were looking for! :-)

-David Warner