Node Designer

A Universal Python node for Autodesk's Maya.

Node Designer simplifies the technical overhead required by MPxNode, allowing users to easily develop nodes with Maya's Python API. As a Python node, it exposes the plugin's compute block in the form of an expression, with input/output plugs dynamically populated.

New in version 2.0:

• 12 genuine Maya node types to achieve complex tasks such as custom deformers and geometry generators.
• AI Assistance to write and compile C++ plugins!

Coming from 1.x? Scenes built with Node Designer 1.x open directly: each node is upgraded in place when the scene loads, and the Script Editor lists what changed. Code that imported mpylib has to be ported to numpy or mpynode.api. Take the 1.x plug-in and mpylib off Maya's paths first, since both versions register the mPyNode node type and only one can load per session.

Authors

• Gene Hansen (gene.hansen@gmail.com)
• Eric Vignola (eric.vignola@gmail.com)

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Install

1. Put the repo anywhere on disk. All paths below are relative to the repo root.

2. Set the two paths before launching Maya:

   # macos
   export MAYA_PLUG_IN_PATH="$PWD/plug-ins:$MAYA_PLUG_IN_PATH"
   export PYTHONPATH="$PWD/scripts:$PYTHONPATH"

   rem windows
   set MAYA_PLUG_IN_PATH=%cd%\plug-ins;%MAYA_PLUG_IN_PATH%
   set PYTHONPATH=%cd%\scripts;%PYTHONPATH%

3. Or copy the repo's userSetup.py into your Maya user scripts folder, then point it back at the repo with MPYNODE_PROJECT_DIR:

   # macos
   cp userSetup.py ~/Library/Preferences/Autodesk/maya/2026/scripts/   # macOS
   cp userSetup.py ~/maya/2026/scripts/                                # Linux
   export MPYNODE_PROJECT_DIR="$PWD"

   rem windows
   copy userSetup.py "%USERPROFILE%\Documents\maya\2026\scripts\"
   set MPYNODE_PROJECT_DIR=%CD%

   Already have a userSetup.py? Append this repo's contents to it instead.

4. Optional — add a shelf button:

   from mpynode.ui import shelf
   shelf.install_shelf_button()

Quick start

Launch Node Designer

from mpynode.ui.mpynode_designer import show_designer
show_designer()

And start building new nodes, or browse any of the provided templates.

Or use the API

from mpynode import MPyNode

n = MPyNode.create(name="myCalc")
n.add_input_attr("a", "double")
n.add_input_attr("b", "double")
n.add_output_attr("sum", "double")
n.set_compute_expression("""
self.sum = self.a + self.b
""")

How it works

Each node stores its Python as text on a plug, so the source travels with the scene and there is nothing to import or deploy. Attributes you add at runtime cannot use Maya's attributeAffects (that is class-init-time only), so MPyNode installs DG callbacks that reproduce the same dirty propagation automatically.

Compiling walks the node's Python AST and lowers it directly to C++, falling back to an LLM only for constructs it cannot translate deterministically. You can then opt-in for further LLM assisted optimization passes, which adaptively attempt to optimize the C++ code's performance.

Full detail in docs/ARCHITECTURE.md.

Templates

36 templates in templates/, at least one for every node type, each with a runnable demo. Browse them in the Designer's Templates tab.

Source code for each template is provided. To compile them yourself — see INSTALL.md.

Documentation

Document	What it covers
docs/index.md	The full API — every node type, attribute types, worked recipes
docs/CHEATSHEET.md	Quick reference for the Python API: create, attributes, expressions, stored vars, compile
docs/ARCHITECTURE.md	How the framework and the compiler are built
INSTALL.md	Install variants, environment variables, troubleshooting
docs/PORTING.md	Per-platform build status and the Windows / Linux recipes
docs/node_types/	One design note per node type
docs/notes/	Contributor design notes for work that is scoped but not built

License

BSD 3-Clause License: Copyright (c) 2019-2026, Gene Hansen, Eric Vignola All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

3. Neither the name of copyright holders nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.