There is a node for Ambient Occlusion. It generates white except where there is something nearby, then it generates a darker shade gray. We use this information to selectively alter the reflectivity or brightness in a shader.

You generally plug it into the parameter that controls the diffuse reflectivity in your shader setup. If you're using the built-in diffuse capability of the root node (poser surface) then that would be the Diffuse_Value. If you're using other diffuse nodes, such as Clay or Velvet, you'd use appropriate parameters on those nodes. It is also possible to plug it directly into color channels to darken any color. This is sometimes used to create "dirty" shaders - shaders that appear to have collected dirt in crevices.

Whoever said 10 times the strength actually meant distance. The distance on the AO node seems to behave or mean something different than the distance on the light-based AO. In many ways, controlling the distance effectively controls the strength of the shadow, so it's somewhat useful to think of the distance as a strength. However, you cannot use it to change how black the deepest shadow is. That would be the job of the strength parameter.

However, the AO node strength actually doesn't work at all. So if you want to adjust the strength you need to combine it with a Blender node, and mix some WHITE in with the AO before you plug it into your diffuse value parameter.

See here for a demo:

http://www.renderosity.com/mod/forumpro/showthread.php?message_id=3099237&ebot_calc_page#message_3099237

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