Screen-Space Ambient Occlusion

AO estimates missing ambient visibility. It must modulate indirect lighting, not repaint all scene color with a dark multiply.

Workflow

1. Verify linear depth and view-space normals.
2. Reconstruct view position consistently.
3. Sample horizon visibility in a controlled radius.
4. Estimate AO and optional bent normal.
5. Denoise with depth/normal-aware filters.
6. Apply to indirect diffuse and environment response.

Read references/gtao-bent-normal-pipeline.md.

Failure conditions