There is a software product out there, but it won't plug into Vegas. You'll need to create the textures/images in the third party, then import to Vegas.
Try http://www.synthesoft.com/ or search Google for some of these. I think there was some shareware for this on Tucows recently too.
You could try Windows Media player which sync's the images to music but I never figured out a way to do a screen capture in full screen mode. Maybe someone else does?
I did it with Flash, and it could probably be done with Windows Media player too.
I have ATI All-In-Wonder graphics card. I enabled TV out and connected it to my D8 camcorder. Played Flash movie in full screen and recorded it on my cam. Then I captured it back to computer with Vegas.
Hmmm....if you can do that, you might try capturing via the camera in analog, and outputting straight to the vegas capture app running in the background, never capturing to tape. Depending on system resources, you should be able to do this.
I use 3ds max for 3d modelling and animation. It can keyframe just about anything, and one of the action-generators for keyframing can be a sound file. You can do some really cool effects; I made an oscilloscope trace follow a song.
The only problem is the software is expensive and not easy to learn. I charged a fair bit of money to make the oscilloscope!!
I think I have a copy of that, and I plan on using that for live visual background for the band while we play live. :-) (as soon as I get a high lumen projector)
I'm looking for something that will output a avi file or some way to capture the output, so I can use it in music videos.
I don't think Arkaos can do that though, from what I remember when I tried it out. The website doesn't mention the output that I could find.
I have done this successfully a few times with Windows Media Player. Using Hypercam to capture 720x576, 25 fps (PAL) files with the Matrox DV codec, my CPU usage hits 100% occasionally but it does capture without dropping frames. PC is a 3.06GHz P4.
You can set different visualizations for the same music and capture them in separate passes, then combine them or cut between them in Vegas. It is very effective.