AmbientOcclusion is a rendering extension focused on simplicity. Instead of having to setup all the materials in your scene, the extension will do it automatically for you. In many cases, getting a photorealistic image of your SketchUp model requires just one click.
The recently released version 3.0 adds support for luminaries, as well as hyper-realistic rendering modes.
AmbientOcclusion comes in two different versions, Pro and Ex. AmbientOcclusion Ex includes all the features of the Pro version, but adds the support for rendering animation and batch rendering. Batch rendering allows you to queue multiple SketchUp scenes to be rendered.
There is a free demo available here:
Here's some getting started videos that show AmbientOcclusions's ease of use:
