Threejs Exposure Color Grading

Exposure and Color Grading

Treat exposure, tone mapping, grading, and output conversion as distinct stages. Tune them from measured HDR signal, not by stacking compensating color operations.

Order

HDR scene
  → luminance meter
  → adapted exposure
  → tone map
  → creative grade / 3D LUT
  → final output conversion

Read [references/scene-referred-color-pipeline.md](references/scene-referred-color-pipeline.md) for the exact 64x36 meter, encoded readback, adaptation constants, 32-cube LUT, and signal-ownership ambiguities.

Failure conditions

• tone mapping occurs in both materials and post;
• exposure is used to repair physically inconsistent light ratios;
• meter weighting and scene framing are not inspected;
• adaptation speed is the same toward light and dark;
• LUT input/output spaces are undocumented;
• sRGB encoding happens twice;
• a display-domain LUT is moved before tone mapping without being rebuilt.

Routing boundary

Use $threejs-bloom for HDR glow contribution and $threejs-image-pipeline when this color path must share ownership with AO, atmosphere, or effect-local render targets.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: scottstts
• Source: scottstts/Threejs-Awesome-Graphics-Agent-Skills
• License: MIT

Install and usage instructions live in the source repository linked above.