You might find that getting all the passes you need feels like a chore at times. Depending on the scale of the project, you might find yourself endlessly adding passes and contributions, hoping that you didn’t miss anything. That doesn’t always need to be the case, however, especially when we are talking about an Ambient Occlusion pass.
Shaun Foster shows how you can use Maya’s VP2’s GPU AO with 80-90% quality with almost no rendering cost. By using the screen-space ambient occlusion setting in Viewport 2, you can get a really quick Ambient Occlusion pass.
It’s not going to provide you with a ton of detail, but in certain situations and scenes, it just might be a huge timesaver.