ZBrushCentral

Cavity map...How?

ZBrush Usage Questions
#1

How do I make a cavity map in Zmapper? I have found no documentation or help on the matter, the zmapper doc only skims over the concept and a few setting, but it doesn’t describe “how” to make one work. When I hit the button to create cavity map it runs through the projection but when its done I get absolutely nothing.

I’d like to somehow project the darker areas of a higher poly subdiv mesh onto a low poly mesh to use it as a base for a diffuse map in another app. Basically, bake the cavity detail from the high as a texture for the low.

#2

Anyone? :ex:

#3

i don’t know but i guess after you create it it kann be found in the texture or alpha palette / slot

#4

Thanks I will check but I’m pretty sure I wasn’t getting results. I was able to project a cavity onto itself through zmapper but after reading a few threads that came up through search it looks like projecting cavity detail onto another model is not implemented yet…

If I can’t do a cavity map I’d like to simply be able to project bump or diffuse information onto a low poly model.But I’d really prefer cavity detail over anything.

Right now I am having trouble painting a diffuse map to be used along side the normal map in a game engine because anything I paint in the diffuse looks to be competing with the normal map detail which has made this frustrating.

I am using two models in zmapper, the low poly has uvmap from 3dsmax and the high poly which has default zbrush uv information so obviously the only way I’d get what I want is through projection. I guess I could sit for many many hours painting in the pores and cracks and such by hand but its completely beyond tedious for me and the time I have for this project. If there was a way to render out the normal map so that it was just shadow information, that would be nice, but since it calculates for all rgb channels I get a texture with asymetrical shadows(if I were to use it for a diffuse texture)

I’m not sure if I’m missing a crucial step or what but it really doesn’t help when I can’t find help for the problem.

#5

Why are you using two models? Trying to generate a cavity map using the ZBrush default UV mapping won’t give you a map that you can paint. The best way to work would be to import your low poly model (with UVs) into the lowest level of your ZBrush model - though the number or vertices must be the same - and in the same order - for this to work. Then generate the cavity map from that level in ZMapper. Make sure you set the Cavity Coverage and Cavity Intensity otherwise you won’t get anything. Once the scan is completed exit ZMapper and your cavity map should be in your texture palette.

And yes, you can’t project cavity maps at the moment.

#6

Do cavity maps work equivalently (using same material slots and stuff) as normal maps?

#7

Although the effect on your model is similar, creating a cavity map using ZMapper is a completely different method from using the material cavity shading settings. For renders outside ZBrush, it is possible to output a texture map of the material cavity shading but it’s simpler to use ZMapper. Materials are specific to ZBrush and its renderer.

Likewise normal maps output using ZMapper are not dependent on material settings. Materials don’t affect ZMapper.

The point of including cavity shading in ZMapper is that it can be included in a standard Normal Map without any problems. The effect when rendered will be similar to an ambient occlusion pass. Being able to output a separate cavity map is a bonus.