Re: Ambient Occlusion node

Already did that like 8 years ago. Using the AO node to detect nearby geometry (and thus conclude you're in a crevice) is a definite way to go. However, there are certain things it won't do right. It can't tell you that something is a protrusion - only that there is no apparent nearby object. So if you're trying to add extra "rubbing" or wear off some paint, you'll end up doing that on anyplace that isn't pointing near something else. So it's not so great for the effect of wear and tear on "exposed" parts.

Also, AO can't tell you if that nearby object is some other object or a part of the same object. (So for example, it will tell you that any part of a prop near the ground or a wall is in a crevice). That may be ok for statues, where stuff near the ground is dirtier and wetter. But it's not a general solution. How about a desktop statue of some kind - should the part near the desk be more dust-filled? (The answer is no)

Still it will be part of the bag of tricks for making "dirty" shader effects. 

But an additional problem is that the behavior of the AO node has changed drastically in recent Poser releases. (The parameters don't get interpreted nearly the way they used to.) And it's full of mesh artifacts I never saw before.

Finally, AO with IDL is a CPU killer. For some reason, the AO node slows to a crawl when IDL is on as well.

So - AO doesn't do what I want, it makes mistakes when I use it, and it means a 30 minute render takes 12 hours instead. 

I'll show you how to use it, but I don't want it for my main technique in dirty shaders.

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