SSAO (Ambient Occlusion)

SSAO, short for screen space ambient occlusion, darkens the places that light has trouble reaching: the creases of a model, the corners where two walls meet, the thin gap under an object resting on a floor. These soft contact shadows give objects weight and make them sit in the scene instead of floating above it.

How it works

Working from what the camera sees, the effect checks for every pixel how much nearby geometry surrounds it, and darkens it the more enclosed it is, multiplying that shading into the picture. Because it works on the finished frame, it needs no extra set-up on the lights and adds depth to every object at once.

Settings

• Radius: how far around each point it looks. Small values give tight contact shadows in seams and under objects; larger ones give broad, soft shading in big corners.
• Intensity: how dark the occlusion gets.
• Bias: a small offset that stops flat surfaces from shading themselves; raise it if you see blotches on open, flat areas.

Use it for

Product shots, architecture and interiors, detailed 3D models, and any scene where objects stand on a floor. The Realistic preset uses it with a small radius and gentle intensity, with a faint bloom on the highlights. It pairs naturally with a directional light for the main shadows and Color Correction to set the time of day.