Render to texture using MR displacement doable?

Kevin Albers

Does anyone have a functional workflow for baking hi-res models down to game-res using render-to-texture in Max, using Mental Ray displacement maps as part of the hi-res stuff? From what I can tell, the Mental Ray renderer doesn’t work properly with render to texture, and the normal Max renderer doesn’t support displacement maps. I may just be doing something wrong, but I can’t tell.
I’d like to be able to detail out some meshes in Zbrush, and export medium-res meshes plus displacement maps out from Zbrush. Max tends to choke when dealing with really hi-res meshes, so it’s a pain to use Zbrush models with 500k + polys.
I know there are alternatives to using Max for baking normal maps, but I really want to be able to bake out all sorts of map types when baking, and most alternatives just bake normal maps.

poopinmymouth

So the height map option in the map types isn't what you want? I always assumed that was a displacement map. (it's the last in the list of map types you can bake out)

Kevin Albers

I want to use the displacment maps on the hi-res objects, rather then generate displacment maps for the game-res. For example: 1-detail out a mesh in zbrush, resulting in a 1 million poly mesh 2-lower the subdivision level a couple of notches, resulting in a 50k ish model 3- generate a displacement map in zbrush, so that my 50k model can look like the 1 million poly model model. 4- import medium res model into max, and assign the displacement map to it 5- bake down to game res using render-to-texture.

This may be more work than it's worth, since I can just skip using displacement maps, and deal with importing super hi-res models in Max, even though they tend to choke Max, especially if they need to be edited much prior to baking.

JordanW

if you're at all interested you can also use zmapper to make a normal map of the super high poly object onto the medium high then it'll work in RTT as long as you use max's render, i used this method on my general.

Kevin Albers

Thanks tinman. That's probably what I will do if using displacement maps is too much of a pain.

FAT_CAP

You can use displacement maps on a low-level ZBRUSH mesh, in combination with TURBOSMOOTH or MESHMOOTH to get a mesh which is pretty much identical to the high-res ZBRUSH mesh and which renders out fine with the standard MAX renderer...never tried it with Mental Ray though.

There are a few steps you need to take to get it to render out well. Theres a pretty good runthrough of the setting people used on the XBRUSH forums. I haven't got the link to hand as Im at work but I'll post it when I get home. I also remember running into some troubles using this method in combination with a ZBRUsh generated bump-map and it AUTO-UV algorithm but I am still not sure if it was my fault and somethign went wrong along the way as I never did get a god answer on the forums.