Paint-da-Fence

[Dave]

What would be suggested to "paint" the ground with a beam?

Here is the scenerio, a beam from a high altitude, say 30,000 feet, scans the terrain below. How would one make what had been illuminated stay illuminated while the beam continues on.
We are talking a radar beam.

I have thought of usind a an Echo effect in AE but this is only good for a still shot.

I thought of shooting a particle system to the surface and have the particles 'stick' to the ground but I don't know if this would give me full resolution of the surface or if it would be speckled.

any ideas? people?

Talk to me so a can get this newbie rating on my profile off. hehe

-dave

[txbob]

I have done things similar to this by rendering 2 passes of the animation, one with the ground glowing ( the entire path glowing) and another with the beam. Then loading the non glow version in the background, and a front projection object with the glow on it. ( remember to set the FP plate to 100% luma and 0 diffusse, or you'll run into lighting problems.) Animate the fp plate following the beam around, and you should get the desired effect.

I had to do a shot where a wireframe of a building had to "grow out of a building site, and then the texture had to "grow" up the wireframe. It was a bit complex, but easy one you figure out the trick.

Good Luck!