I'm trying to Bake Geometry's ambient occlusion into Vertex Colors, I can bake them to textures, using mental ray renderer and overriding the scene materials with mental ray's ambient occlusion mtl, but what I need is to bake them into vertex colors. I have tried VertexPaint->Assign Vertex Colors, but it bakes only radiosity lighting, and not the ambient occlusion how can I do it ? btw, I'm using 3dsmax7 thanks

I have the same question too!

But I saw u metioned that u can bake the ambient occlusion into texture as a map by ussing metal ray, right? Can Vray1.5 also work well like that?

Besdies, a dumb question, can I ceate a "light sphere" to simulate a average light source to simulate real-world skylight and create a ambient occlusion look, or any better method to create a ambient occlusion look?

thans !

Quote: Can Vray1.5 also work well like that?

actually I don't know about that, I use mental ray built into 3dsmax7 for ambient occlusion

what I do is assigning the Mental Ray renderer, the build e "mental ray" material and assign the surface to "Ambient/Reflective Occlusion", then you can tweak the AO settings in the matarial.

now you can wether set the matarial to every object or simply assign the material to the whole scene by opening "Render", in "processing" tab check the Material override and bind the ambient occlusion material to it.

now if you render the scene, it will be rendered with AO.
and for lightmaps you can do a "render to texture" for every mesh.

Quote: Besdies, a dumb question, can I ceate a "light sphere" to simulate a average light source to simulate real-world skylight and create a ambient occlusion look, or any better method to create a ambient occlusion look?

I don't think that would be the correct AO look !

Just curious. Why do you want to bake ambient occlusion into the vertex colors as opposed to just using an AO map? I guess the obvious answer is that it's computationally cheaper. It seems if you don't actually want to use an AO map in your object's shader that you should just use the ambient occlusion as a seperate layer in your PSD file for your diffuse/color map and set it to multiply at the top of the stack. It won't be dynamic, but visually it will look better than simply using the vertex colors, and since whatever you're creating will have a diffuse map anyway it will save you a little bit of processing power. This is actually a technique that is used often by the various projects I work on. Mass Effect is one such project that I'm working on that uses this technique.

WorldPlanter, A downside to baking AO in your diffuse is that a directional light pointing at that area of AO will not display correctly results the human eye might expect. On the other hand - a little fake AO is better than none. Putting it in a seperate map , channel of another map or vertex colours would allow you to mix with the lighting correctly in a shader.

sepul
In max you could bake your AO into a texture, then assign the texture to the object and make vertex colours based on that texture. There is a seperate vertex baking tool from vertex paint, I think - not looked at it recently so don't know if it has any different features. It should allow you to bake texture colour into verts.

wangmarc, if you use a sky light in max and turn on the lighttracer,
and only place the single object in your scene, you will get AO.
It pretty much the same thing.

Not tried Vray with render to texture.

btw on subject of per vertex AO - http://vcg.sourceforge.net/tiki-index.php?page=ShadeVis

Quote: Original post by mikiex
WorldPlanter, A downside to baking AO in your diffuse is that a directional light pointing at that area of AO will not display correctly results the human eye might expect. On the other hand - a little fake AO is better than none. Putting it in a seperate map , channel of another map or vertex colours would allow you to mix with the lighting correctly in a shader.

As I mentioned it won't be "dynamic", by which I meant that it won't mix or react to the lighting as you said. But it's computationally the least expensive approach if you're attempting to get the "effects" of ambient occlusion. As you said, it's faking it.