# GT7 Tonemapping for Substance 3D Painter

OpenColorIO configuration for Gran Turismo 7 color management in
Substance 3D Painter. It uses a 65x65x65 GT7 LUT with an `lg2 [-9, 10]`
HDR shaper.

## Setup

1. Open a project in Substance 3D Painter.
2. Open `Edit > Project Configuration`.
3. Set Color Management to `OpenColorIO`.
4. Set the OpenColorIO configuration to `Custom`.
5. Select `ocio/config.ocio` from this directory.
6. Confirm the project configuration changes.
7. Select `GT7 SDR` from the display-transform dropdown in the 3D viewport.
8. Open **Display Settings > Post Effects** and disable **Tone Mapping**.

Use Painter's normal material shader, such as `ASM Metal Rough`. The GT7
transform is applied to the viewport output, including the model and HDRI
background.

Painter's legacy tone mapping is not used in OpenColorIO mode. If tone mapping
controls remain available, use `Linear` and disable any additional Color
Profile LUT to avoid processing the image twice.

The display transform does not alter exported material textures.

## Files

- `ocio/config.ocio`: Painter-compatible OpenColorIO configuration.
- `ocio/luts/gt7_sdr_ictcp_shaper_65.cube`: GT7 SDR display LUT.
- `ocio/luts/srgb.spi1d`: Standard sRGB transfer curve.

See `THIRD_PARTY_LICENSES.md` for the GT7 LUT source license.
