Render a scene using Ambient Occlusion

Turn on WindowDisplay > Hardware Shade.
Choose Render > Ambient Occlusion > Compute.
When you first compute ambient occlusion, the tool and display will change to the Unify Surface Orientation tool. For further information about unifying normals, see Surface Edit > Orientation > Unify Surface Orientation .
Render the scene.
After ambient occlusion is calculated using Hardware Shading, the calculation is used (if it has not been toggled off with Render > Ambient Occlusion > Toggle Display) for software rendering.

If you change your scene by changing or replacing surfaces or transforming items, recalculate the ambient occlusion map and use Hardware Shading before rerendering.