Ambient Occlusion Baking

[pauls]

Hi,

Would someone be kind enough to either point me to a quick and easy guide to baking ambient occlusion textures using blender - or perhaps give me a quick explanation of an easy method of doing it.
I've built a model in another program but would like to import into blender for texturing.

Many thanks.

Cheers
Paul

[karma99]

There are quite a few tutorials around on UV texturing/unwrapping in Blender so I'll let you find those, however here is a quick step through of a render bake once you're all unwrapped
If you want to try it quickly you can use the auto-unwrap - Press U, "Unwrap (Smart Projections)" - but I'd advise doing it carefully piece by piece for your proper unwrap.

1. Delete all lamps in your scene
2. Press F5 (Shading) and then select the little World icon to the right (says World Buttons if you hover over it)
3. In the tabs below this click the one marked Amb Occ and then click the big button marked Ambient Occlusion. Only thing to change here is Samples (defaults to 5). I tend to use 12 for a decent quality render. Also at the bottom Energy is set to 1.0. You might want to play with this as you try it out later, but I tend to use 1.0 and then adjust the contract/brightness of the baked image as I overlay it on my base textures.
4. Select your mesh, go into edit mode, select it all, go into the UV/Image Editor window and click "Image", "New" and set the size to what you want your bake to be. A totally black image will now be visible under your unwrapped mesh.
5. Go back to the 3D editor, tab back out to object mode (NOT edit mode) and then click Ctrl-Alt-B and press 2...
6. Wait...
7. Wait more.. it takes a while!
8. When it's done, go into the UV/Image editor window and there is your baked image ready to use as an overlay/multiply layer. Select Image, Save As.. and you're done. Also if you press alt-z in 3d mode you'll see the baked image applied to the mesh in the "live" window.

That's a super fast breakdown of minimum steps needed to get a bake from an unwrapped mesh. There are a bunch of settings (shadow depth, distance for items to cast shadows on each other, etc) but the defaults are pretty good in my experience.

[pauls]

Hi Pete,

Many thanks for your detailed reply. - I found quite a few tutorials - but not any that made sense immediately. - I'll keep looking tho'.
In the meantime I'm just going to follow your detailed instructions and see what happens.

I normally build in 3D Studio Max or Gmax - however I wanted to find a simple step-by-step method of building models that would suit a novice and would use freely available programs.
I reckon that Google Sketchup must be one of the easiest programs to learn and is very intuitive. I'm not sure what to do about UV Mapping - 3D Studio Max is probably quite good in its automatic modes - but is not exactly free - it also seems essential to have ambient occlusion since most people won't have the skill to paint shadows to that standard. Another angle to this is that I'm also hoping to speed up the building and texturing of my models so that I can finish a route of custom built assets in one lifetime - So perhaps highly detailed 3D Studio Max models right next to the track then something that still looks good but is much simpler and easier to build a little bit further away and into the distance.

Cheers
Paul

[ikesmith]

will this site http://www.44090digitalmodels.co.uk/ be of use to you.
I found it so for railway engineshttp://www.44090digitalmodels.co.uk/

[pauls]

will this site http://www.44090digitalmodels.co.uk/ be of use to you.
I found it so for railway engineshttp://www.44090digitalmodels.co.uk/

Some excellent tutorials - Many thanks.

Cheers
Paul

[pauls]

Another tutorial - also covers World Setup.......

http://wiki.flightgear.org/index.php/Ho ... in_Blender

Cheers
Paul