3D LUT
Applies a 3D lookup table from a .cube file for color grading or technical color transforms.
Category: Color Menu path: Color > Lut3D
Ports
| Port | Type | Direction | Description |
|---|---|---|---|
in | imageRgba16f | input | Input image |
out | imageRgba16f | output | Color-graded result |
Parameters
| Param | Type | Default | Description |
|---|---|---|---|
path | string | "" | Path to a .cube file. Use the file picker or drag from Assets panel. |
intensity | scalar | 1.0 | Blend between original (0) and fully graded (1). Keyframeable. |
inputSpace | enum | sRGB | Color space the LUT expects. Most creative LUTs expect sRGB; technical transforms may expect Linear. |
Expose Channels
| Port | Type | Overrides |
|---|---|---|
intensity_in | scalar | intensity |
How It Works
Loads a standard .cube file (the industry-standard 3D-LUT format) and uploads it as a 3D GPU texture. The shader converts from Caddis's linear working space to the LUT's expected input space (sRGB or Linear), performs a 3D texture lookup with hardware trilinear interpolation, converts back to linear, and blends with the original based on intensity.
Supports LUT sizes from 2 to 256 (standard sizes are 17, 33, or 65). Custom domain ranges are parsed but most LUTs use the default 0-1 range.
Usage Examples
Basic: Apply a creative LUT
- Add a Lut3D node between your ImageSource and Output
- Click the "..." button to browse for a .cube file
- Adjust intensity to taste (try 0.7 for a subtle grade)
Creative: Animated LUT intensity
Connect a Time node through Math (remap 0-1) into the intensity_in expose channel to fade a color grade in over time.
Tips
- Leave inputSpace on sRGB for most creative LUTs (film emulations, color grades)
- Switch to Linear only for technical transforms (camera-specific conversions, ACES)
- Empty path = passthrough (no processing cost)
- The LUT is cached by file path + modification time — editing the .cube file on disk updates immediately
Related Nodes
- ColorCorrect — manual CDL-style grading
- Curves — per-channel curve adjustment
- Colorize — scalar-to-color ramp mapping