Lighting and Rendering [2] Arnold Part 17: Ambient Occlusion

Unedited Image (aiAmbientOcclusion1 assigned to object and plane)

aiAmbientOcclusion | Attributes: Samples- 6.0; Spread- 1.0; Falloff- 0.0

No Glass

Final (Ambient Occlusion Pass and Beauty Pass composited together in Adobe Photoshop CC 2017)