C44Matrix

A Nuke plugin for applying 4x4 matrix transformations to pixel data — an extended version of Nuke's built-in ColorMatrix.

Originally created by Ivan Busquets. This fork adds Axis node support in addition to the original Camera input.

Features

• Apply 4x4 matrix transformations to RGBA pixel data
• Automatic matrix extraction from Camera or Axis nodes
• Transform position passes between coordinate spaces (world, camera, NDC, screen)
• Manual matrix input for custom transformations
• Matrix operations: invert, transpose, W-divide

Compatibility

Platform	Nuke Version
Windows	14.1+
Linux	14.1+
macOS	15.0+

Pre-built binaries available in COMPILED/

Installation

1. Copy the plugin files from COMPILED/ to your .nuke directory
2. Add to your init.py:

   nuke.pluginAddPath('/path/to/C44Matrix')

3. Restart Nuke

Usage

C44Matrix transforms RGBA channels as a 4D vector (X, Y, Z, W). For position pass transformations, ensure alpha is set to 1.

Input Modes

Manual Input Enter matrix values directly in the 4x4 grid — useful for matrices from Python scripts or render metadata.

From Camera (original) Connect a Camera node to automatically extract transformation matrices.

From Axis (new in this fork) Connect any Axis node (or Axis-based node like Locator, Light, etc.) to extract its transformation matrix.

Available Matrices

Matrix	Description
Transform	Full transformation (translation + rotation + scale). World Space ↔ Camera/Object Space
Translation	Translation component only
Rotation	Rotation component only
Scale	Scale component only
Projection	Camera projection matrix (aperture, focal, win_translate, win_scale, roll). Camera Space ↔ NDC
Format	NDC (-1 to 1) → pixel coordinates for current format

Options

Option	Description
Invert	Apply the inverse of the matrix
Transpose	Swap rows and columns
W Divide	Divide result by W component (typically needed for projection matrices)

Common Use Cases

• Converting world position passes to camera space
• Projecting 3D positions to screen coordinates
• Transforming position data to match relocated 3D elements
• Building coordinate space conversion gizmos

Building from Source

Platform-specific CMake files are provided:

• CMakeLists_WIN.txt
• CMakeLists_LINUX.txt
• CMakeLists_MAC.txt

See building_step_by_step.txt for detailed instructions.

Requirements

• CMake
• Nuke NDK (included with Nuke installation)
• C++ compiler (MSVC on Windows, GCC on Linux, Clang on macOS)

Changes in This Fork

• Axis node support — Connect any Axis-based node to extract transformation matrices, not just Cameras

Credits

• Original Author: Ivan Busquets
• Axis Support: Peter Mercell

License

Based on the original C44Matrix by Ivan Busquets from Nukepedia.