Ambient Occlusion Tutorial?!?

Fraya713

Hey, I am trying to create an ambient occlusion map in 3D max, I know there's a way you can do this where 3D max will pass over the object and create a map for me, but all I have found online are tutorials on how to create an ambient occlusion pass over my render and I can't remember for the life of me how to do it..

Please, can someone either give me a site where this is on there or quickly tell me how to do it, thanks, I really appreciate it!

Reverenddevil

Here you go...

http://www.game-artist.net/forums/vbarticles.php?do=article&articleid=37

renderhjs

if you want to bake it into textures better use Blender or even Better xNormal. Booth are free and have a quick setup just for baking AO maps.
DOing the same in Max is still a hassle to setup - and even more a pain when you want to remove the environment settings and other related changes back to normal to render in a regular way.

Mark Dygert

renderhjs, render presets... and the only hassle with 3dsmax is setting up the RTT window for each object. xNormal is great, but why go learn another app and become defendant on it when it might not be available at the next place he works. I'd suggest getting the standard work flow down and then branching out and seeing whats the best for what he needs.

The official way is to use Mental Ray and Render To Texture. Switch your render'er to Mental Ray and bring up the Render to Texture dialog (just like the skylight tutorial) only now a new map will appear called "Ambient Occlusion(MR)". This will give you a true AO map. It's results are often grittier making it great for dirt passes.

I personally use the skylight method (but with a custom light dome instead of the skylight object) and render out a diffuse texture with lights and shadows enabled (in RTT). Gives me a TON of control way more then Xnormal or Mental Ray.

jogshy

Vig wrote: »

I personally use the skylight method (but with a custom light dome instead of the skylight object) and render out a diffuse texture with lights and shadows enabled (in RTT). Gives me a TON of control way more then Xnormal or Mental Ray.

Wait and see :P

Mark Dygert

That's the really great thing about XNormal, you listen, and put in features like a mad man! I really do love it and its crazy awesome for making normal maps. But I can't use it at work.

Just to expand on my max AO work flow (to help you make XNormal more kick ass).
- I like to place dominant lights, like if I know an object will be in the shadows with direct light on it, or positioned toward the sun at a specific angle.
- I use different colored lights which helps give me different gray scale values, I also use those same lights to tint my colored spec maps. Brown by the ground blue on anything facing the sky.
- For single stationary props, I like to export map geometry from whatever editor I'm using and incorporate that into the bake. If there are other props like pipes, wires vents I'll also place them and bake the AO together.
- Since lights don't carry over with most exported geometry I build little cube helpers and place them where the lights would be and make notes of the settings.
- On a few rare occasions I've used whatever game engine to render out cube/env maps and use that has HDRI lighting in 3dsmax.

I'm not saying this is normal for people baking AO but this is the kind of flexibility I was talking about. Most of this is kind of rare occasions and only subitly enhances the AO and Spec.

Microneezia

does anyone know why this might be happening? Im getting AO maps that look all faceted. I have tried with zero smoothing groups, 1 smoothing groups and many smoothing groups. I cant seem to get a smooth result from RTT like if I simply render it out with F12.

Using max 9, render to texture, I dont have a hi poly object, i want the to use the same object but render an AO map to UV. Actually this is a diffuse RTT map test, with lighting and shadows active, as suggested below. I have not activated the cage in RTT since there is no high poly sculpt. I chose AO map from MR.

I have used this feature before with good results but only when using cage and had a Hipoly to pull light detail from. Is that my issue? does everyone RTT AO maps with high poly only>?

MR render:



Render to texture:

Neox

first guess, you have overlapping uvs, like all 4 sides of the collumns on the same uvspace, just move all but one uv cluster on that space +1 unit out of the uv space before baking

Japhir

http://www.gameartisans.org/forums/showthread.php?t=5000

Microneezia

Neox, that's absolutely correct, as you know. thanks for your help, this is perfect information.

jmiles

wow.. old thread.. however.. thanks japhir.. sweet tut.. i havent looked at marcas's work in a long time.. he's really come a long way