RSSAO

r_SSAO

Screen space ambient occlusion:
0 - disabled
1 - SSAO technique with normals
2 - SSAO technique with normals and temporal accumulation
3 - Volumetric Obscurance technique with jittering
4 - Volumetric Obscurance technique with jittering and temporal accumulation (Consoles only) 
5 - VO variation with multiple radii