PDA

View Full Version : Vertex Lighting



Philbert
01-09-2010, 11:09 AM
I had never even heard of vertex lighting before but I discovered the concept and am curious about it. I opened Vertex Paint and found some basic lighting in there, I'm curious to learn more about it. Anyone know of any tutorials? Also, and this is a long-shot, any idea if it will transfer over to 3ds max via FBX or Collada?

Philbert
01-09-2010, 12:30 PM
I've made up this simple test object and applied some vertex lighting to it, which you can see in Modeler if you load it and open Vertex Paint (Lighting tab). But I don't know how to see that light anywhere outside of Vertex Paint.

Andy Meyer
01-18-2010, 03:42 PM
you can do weight maps and use it on the luminosity. works with GI.

Philbert
01-18-2010, 03:48 PM
Thanks but what got me interested is for game use. max apparently has some thing specifically called vertex lighting, which lead me to look into it and find it in Vertex Paint. Maybe it was never finished. I tried turned on radiosity with my test object and didn't see any difference.

warmiak
01-19-2010, 02:02 PM
Thanks but what got me interested is for game use. max apparently has some thing specifically called vertex lighting, which lead me to look into it and find it in Vertex Paint. Maybe it was never finished. I tried turned on radiosity with my test object and didn't see any difference.

Vertex lighting for games is simply baking illumination into vertex colors.
It is no different than baking illumination into textures except not requiring a separate texture channel and being highly dependant on your geometry ( you are not going to "bake" much into a single quad)

People used to do that for to (crudely) simulate ambient occlusion - I don't think these days it is being used so much since just about everybody does per pixel lighting these days ( and more and more games simulate ao with a postprocessing pass)

Philbert
01-19-2010, 02:31 PM
I think I see. So I guess Vertex Paint can't do it without hand painting the colors on. I had kind of assumed you'd have a texture map for the colors, then the vertex lighting would just alter that to make it lighter or darker. I understand its not used as much today but I was doing an art test for Gameloft, since they work on mostly small games for iPhone and the like, then they probably need to try whatever they can to reduce the memory.

warmiak
01-19-2010, 03:31 PM
I think I see. So I guess Vertex Paint can't do it without hand painting the colors on. I had kind of assumed you'd have a texture map for the colors, then the vertex lighting would just alter that to make it lighter or darker. I understand its not used as much today but I was doing an art test for Gameloft, since they work on mostly small games for iPhone and the like, then they probably need to try whatever they can to reduce the memory.

I am not sure if it can do it ... I thought there was a way in Layout to bake illumination into vertices but I have never tried it.

I did use VertexPaint to manually paint some colors into my gems for my iPhone game Anigma to tint the model ( in addition to fake env mapping which was done programmatically )

http://www.warmi.net/tmp/anigmarec.mov

I am not sure how well baking illumination into vertices would work for iPhone style models since you are trying to get away with as little geometry as possible.

On the other hand I did use Lightwave to create lightmaps for a demo I did a while ago - it works much better as it is independent of your geometry count.

http://www.warmi.net/tmp/stonedemo.mov

I use Lightwave for everything I do on the iPhone ... how are you guys exporting your models from Lightwave ?

Philbert
01-19-2010, 03:37 PM
I don't know how most studios do it but I know that LightWave works great for Unity and Unity has an iPhone version of their engine. (See the November LightWave newsletter where I wrote a tutorial)