Contributing to mrHelloWorld

February 26, 2026 · View on GitHub

Thank you for considering contributing to this project. This guide explains how to add new example nodes, write tutorials, and submit your work.

Adding a new example node

  1. Create a new file in meshroom/helloWorld/ following the naming convention: HelloYourFeature.py.
  2. The class name must match the filename (e.g., HelloYourFeature.py contains class HelloYourFeature).
  3. Follow the patterns established by the existing nodes:
    • __version__ = "1.0" at the top
    • Module-level imports: import os, from meshroom.core import desc, from meshroom.core.utils import VERBOSE_LEVEL
    • Lazy imports for heavy libraries inside processChunk
    • try/finally with logManager.start() / logManager.end()
    • Every parameter has name, label, description
    • category = "Hello World"
  4. Add comments explaining what the node demonstrates. This is a teaching repository — clarity matters more than brevity.
  5. Update the nodes table in README.md.

Code style

  • Match the style of existing nodes. Consistency is more important than personal preference.
  • Use chunk.logger.info() / .warning() for user-facing messages.
  • Use .format() for string formatting to match the style of existing Meshroom plugins and nodes in this repository.
  • Keep imports organized: standard library, then meshroom, then lazy imports inside processChunk.

Writing a tutorial

  1. Create a new file in docs/tutorials/ following the numbering convention: NN-hello-your-feature.md.
  2. Structure your tutorial with these sections:
    • What you will learn
    • Prerequisites
    • The code (with annotations)
    • How to test it in Meshroom
    • Expected result
    • Screenshot placeholders
  3. Include at least one code snippet from the node file.
  4. Add at least one screenshot placeholder referencing docs/images/.

Adding screenshots

  1. Take screenshots from the Meshroom UI showing:
    • The node in the node graph
    • The parameter panel
    • The output in the 2D viewer (if applicable)
  2. Save them in docs/images/ with descriptive names: hello-your-feature-node.png, hello-your-feature-output.png.
  3. Recommended resolution: 1200px wide or larger.
  4. See docs/images/README.md for the full naming convention.

Pull request process

  1. Fork the repository and create a branch for your contribution.
  2. Implement your changes following the guidelines above.
  3. Test your node in Meshroom (set MESHROOM_PLUGINS_PATH and verify it loads and computes).
  4. Submit a pull request with a clear description of what your node demonstrates.

Ideas for future nodes

Contributions demonstrating any of these patterns are welcome:

  • HelloDocker: A node that wraps a Docker container for processing.
  • HelloShapeList: A node using desc.ShapeList for multiple shapes.
  • HelloPushButton: A node with a PushButtonParam for interactive callbacks.
  • HelloMultiDynamic: A node using MultiDynamicNodeSize with parallelization.
  • HelloGroup: A node demonstrating GroupAttribute and ListAttribute patterns.
  • HelloNetwork: A node that communicates with an external service or API.

If you have other ideas, open an issue to discuss before starting implementation.