Materials Question - How would you do "Chase Lights" for an electric sign

[DemoMan2]

Hi Guys,
I was wondering how you would set up a material to do "Chase lights" like you see on every casino in Vegas. Any Ideas?

[nabiul]

Hmm there are probably many approaches you can take. This one is pretty complicated.

I would make my model to have the path of the lights be small segments of polygons that I would uv unwrap in their own channel so that each segment covers the texture area from side to side evenly; only one of them would cover the texture area, the others would use texture tiling. Then in the material editor I would assign a texture of some lights lined up horizontally to that specific uv channel and use a panner to move the lights. It would take some serious work to get the uv unwrapping and the timing of the panner right so that there isn't a 'jump' when the panner reaches it's end and resets.

To get realisitc chase lights, you would need to find a way to switch between textures or maybe a mask that blocks the emissive of the lights to actually turn them on and off instead of moving the lights. I don't know how to do this, but there probably is a really complicated way in the material editor.

[DemoMan2]

Interesting idea Nabiul. The alternating mask idea sounds like it might work out the best for what I have in mind.

[redbox]

simple panner, or rotator
http://img191.imageshack.us/img191/4915/lightsxj.jpg

or lerp with UVs for every object on it's place...
http://img38.imageshack.us/img38/728/lights2b.jpg

TimeVarying materials also can be useful.