LUT Cube Analyzer Node

LUT Cube Analyzer takes the image cube (modified by the color correction nodes) as input and analyzes the color transform encoded in it. It then writes a standard LUT file that you can:

• Load into File LUT (Fusion or the DaVinci Color page).
• Share with a colorist or another editor.
• Use in Premiere, After Effects, Nuke, Flame, etc.
• Keep in a personal library of looks.

• Effects Library: Tools > LUT > LUT Cube Analyzer
• Quick add: right-click in the Node Editor → Add Tool > LUT > LUT Cube Analyzer

1. Cube Creator → generates the neutral image cube.
2. Color Corrector / Curves / HLS (a grading chain) → the cube is transformed into the look you want.
3. Cube Analyzer (this node) → analyzes the transform and writes a LUT file.
4. (Outside Fusion) → the file is used elsewhere: File LUT in other projects, the DaVinci Color page, Premiere Lumetri, After Effects Lumetri, Nuke OCIOFileTransform, etc.

The Cube Analyzer is the export to file step. The Cube Apply is the direct application step (no file). Both can live in the same comp.

• Input (orange) - connect the output of a node that modifies the image cube (typically Cube Creator → CC → Analyzer).

Note: if you connect a Cube Creator directly (with no changes), the Analyzer produces a neutral 1:1 LUT (no-op). Not useful in itself, but it lets you check that the pipeline works.

Exporting a custom LUT:
LUT Cube Creator → Color Corrector (grade) → Curves → LUT Cube Analyzer
                                                           ↓
                                                  Type = .cube
                                                  Filename = "my-look.cube"
                                                  [Write File]

Complex grade with several nodes:
Cube Creator → CC1 → Curves → Hue Curves → CC2 → Cube Analyzer → File

Type

Output format:

• .cube (ALUT3) - the most universal format (Adobe, DaVinci). Recommended.
• .3dl - Autodesk Lustre / Flame format.
• .itx - IRIDAS format.

Filename

Path + name of the output file. Use the Browse button to pick the folder. Use an extension that matches the chosen Type.

Write File

Button that writes the file with the current settings. Click it after each change to the grade to export again.

.cube (ALUT3)

Adobe/DaVinci format. Readable text. Compatible everywhere (Premiere, AE, DaVinci, Nuke, Flame, Avid, etc.). The default choice.

.3dl

Autodesk format. Binary or text depending on the implementation. Mostly used in broadcast post-production (Flame, Lustre).

.itx

IRIDAS format (now part of Adobe). Less common, limited compatibility.

Advice: always export to .cube unless a closed pipeline specifically requires another format.

• Building a LUT library - grade the cube with different looks (warm, cool, desaturated, contrasty) → export each one as .cube = a reusable collection.
• Handing a look to a colorist - grade in Fusion, export to .cube, send it to the colorist who can apply it directly in the DaVinci Color page or other software.
• Cross-platform consistency - export a look to make sure the result is identical in Fusion, After Effects and Premiere - each app loads the same .cube.
• Collapsing a correction chain - if the chain is slow, Analyzer → File LUT in a new comp = a much faster render (one LUT instead of N nodes).
• Backing up a grade - export the look to a file to keep a copy independent of the original Fusion comp.
• Client deliverable - deliver the final .cube with the render so the client can see how the color grade behaves on other similar content.

• Write File = manual button - the Analyzer does not save automatically. You have to click Write File every time you change the grade and want to refresh the exported file.
• Name files explicitly - "look-warm-2026-vB.cube" rather than "lut.cube". Essential for a clean library.
• Cube precision = file precision - if the Cube Creator is set to 33³, the .cube file will hold 33×33×33 samples. For more precision, set the Creator to 65³.
• Non-color transforms are not encoded - sharpen, blur and distortion will not make it into the LUT. Only pure per-pixel color changes are captured.
• Test with File LUT after export - load the exported .cube into a File LUT node and compare it visually with the source chain. It should be identical.
• .cube by default - unless a very specific pipeline requires .3dl or .itx.