Find these options under Visualization > Advanced OpenGL Settings.
Ambient Occlusion Shadows - Activates ambient occlusion calculation.
Screen Space Ambient Occlusion Settings - Opens the Screen Space Ambient Occlusion Settings dialog for enabling SSAO and defining the following options:
Radius - The radius of the virtual hemisphere outside which occlusion is ignored.
Intensity - The darkness of the occlusion. The higher the value, the darker the shadows.
Blur Amount - The amount of blur to apply to the occlusion.
SSAO provides an efficient, realtime approximation of the baked ambient occlusion (AO). Although SSAO will never be as good as precomputed AO, or even baked lighting and shadows, SSAO is good for quick previews.
Geometry Light Sources - Treats self-illuminated geometries as light source. Only in OpenGL render mode. Only active if Realtime Shadow is selected.
Backface Culling - Activates/deactivates backface culling. Backface culling renders only the faces with normals pointing toward the camera.
Occlusion Culling - Renders visible geometries only; the render engine excludes polygons/patches hidden by other objects on rendering.
Depth Only Pass - Renders the scene once, using only the depth values. It can be used for optimization with complex shaders.