Tutorial: Ambient Occlusion - Baking AO with Light Tracer

[retardedmonkey]

Here is...my first tutorial...so hopefully it will make some sense and I wont lose you guys half way through. I'll show you guys how to render out an AO map using a skylight and the light tracer...if you know how to render out normal maps this shouldn't really be to much of a suprise to ya. Either way...here we go

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[glynnsmith]

Thanks for posting this, dude. I've read about how to get renders with light tracer, but I've never seen anything on baking light tracer out to a texture.

One quick question: Does the colour of the material work best if it's the default mid-grey, or would it be better to use white, so that it can be knocked out with PS's multiply blendmode?

Cheers mate. Nice tutorial

G

[retardedmonkey]

Thanks bro

Actually that would be a good idea, whatever material is on your object when you render it out is what will be rendered on the AO map. So yeah it would be smart to make the material white, or just a brighter color in order for that to work even better in photoshop. Really you can use whatever color you want, I just usually leave it on grey because I've found I use the AO maps as reference to where objects are intersecting each other, it really helps me see how they all work together.

[doylle]

Great stuff, I use the exact same method.

About the color of the material, it doens't matter what color you use. If you hit render, you will see your texture rendered to the output dialog, and that one will have the color of you material, but your actual lightingmap (the file you saved) will only contain lighting infomration, and no color information. (so that one will always be just black 'n' white).

cheers

[requiem2d]

Thanks Mike Another nice thing is to change the background color in order not to have the black bleed on the white, makes for cleaner edges.

[Mist]

do you need to do an AO pass if your using a normal map?

[TychoCelchuuu]

You never need an AO pass for anything, but whether or not you use a normal map doesn't really make a difference. It's helpful for al ot of things, like determining where you would paint in shadows or dirt on a texture, or using it as pre-shading to give some more variety to your texture flats before you start painting.

[retardedmonkey]

Yea when I use normal maps I usually use the AO map to know where everything thing is on the model...it helps, like Tycho said, to paint dirt and stuff. Really with normal maps you want to refrain from using to much lighting because it is better if the lighting is realtime...so your shadows will move on the model.

So normally when I do normal mapped objects I have a shadow map on multiply set at a lower opacity or just dont have one at all. But there is really no set rule of having one or not...just experiment with it on and off and see what looks best.

Req good point if you do like G says and set the material to white and then set the background to white, it will help keep the edges cleaner....so that would be a better way to do it.

[Flakk]

I don't understand what you use this for :/. What do you do with the result?

[andrei313]

It helps a lot You should read this: http://www.game-artist.net/forums/showthread.php?t=42