QuiltiX 0.4.1

MaterialX Graphical Node Editor

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QuiltiX is a graphical node editor to edit, and author MaterialX based materials of 3D assets. It includes a viewport based on OpenUSD's Hydra, which enables viewing your assets in any renderer supporting both Hydra & MaterialX.

Table of Contents

• Requirements
• Installation
  • From PyPi
  • From Zip
  • From Source
• Running QuiltiX
  • Running QuiltiX using hython
• Integrating with your environment
  • Adding Hydra delegates
    • Arnold
    • Karma
  • Adding custom MaterialX Node definitions
• Platform support
• Contributing
• License

Requirements

QuiltiX requires Python 3.9+ as well as compiled versions of USD and MaterialX.

Installation

From PyPi

pip install QuiltiX

If you additionally require pre-built binaries for MaterialX & USD we currently provide these for Windows. On Linux you need to provide your own binaries for now. Here are linked instructions for MaterialX & OpenUSD

pip install QuiltiX
pip install git+https://github.com/PrismPipeline/OpenUSD_build.git@22.08-win
pip install git+https://github.com/PrismPipeline/MaterialX_build.git@1.38.3-win

From Zip

For Windows a zip containing QuiltiX and all required dependencies can be downloaded from here.
Just extract and execute the QuiltiX.bat

From Source

1. Clone the repository

git clone https://github.com/PrismPipeline/QuiltiX.git
cd QuiltiX

2. Install the dependencies

This will install the base python dependencies, excluding any development dependencies, MaterialX & USD

pip install . 

Additional install options

If you want want to contribute it is recommended to install QuiltiX in development/editable mode.
It is also recommended to also install QuiltiX's dev dependencies.

pip install -e .[dev]

For more information see pyproject.toml

Running QuiltiX

python -m QuiltiX

Or if you installed QuiltiX via zip you can execute the QuiltiX.bat after extracting.

Running QuiltiX using hython

QuiltiX can be run from hython, which is Houdini's python executable. This way you can use Houdini's built USD and MaterialX and don't have to worry about providing your own.
You will also be able to use Render delegates for Houdini like Karma. Read more in the Karma section.

Hython instructions

You will still need some additional libraries required by QuiltiX, so it is still necessary to install the dependencies mentioned in Installation.
You can then execute QuiltiX while making sure that both QuiltiX and its python dependencies are in the PYTHONPATH environmenv variable:

cd QuiltiX_root
set PYTHONPATH=%PYTHONPATH%;./src;/path/to/python/dependencies
/path/to/hython.exe -c "from QuiltiX import quiltix;quiltix.launch()"

Or if you have a virtual environment

cd QuiltiX_root
/path/to/venv/Scripts/activate
set PYTHONPATH=%PYTHONPATH%;%VIRTUAL_ENV%/Lib/site-packages;./src
/path/to/hython.exe -c "from QuiltiX import quiltix;quiltix.launch()"

Note that currently both the Storm as well as HoudiniGL render delegates do not seem to work in QuiltiX when being launched from hython.

Integrating with your environment

QuiltiX tries to rely as much as possible on pre-existing environment variables from MaterialX/USD to extend its systems.

Overview over the most important Environment Variables:

Environment Variable	Purpose	Variable Type	Example
PXR_PLUGINPATH_NAME	Paths to Hydra delegate plugins	Paths
PXR_MTLX_STDLIB_SEARCH_PATHS	Paths to standard MaterialX node definition locations	Paths
PXR_MTLX_PLUGIN_SEARCH_PATHS	Paths to custom MaterialX node definition locations	Paths
HD_DEFAULT_RENDERER	Name of the default Hydra delegate for the viewport	String	GL

Adding Hydra delegates

NOTE
The Hydra renderer needs to support MaterialX for it to work in QuiltiX.

What is a Hdyra Delegate?
"Hydra Render Delegates are bridges between the Hydra viewport and a renderer. [...] The Hydra Render Delegate system allows the ability to switch out the backend renderer for the viewport data in Hydra. [...]"^[src]

The Storm Hydra Delegate by Pixar is both shipped with USD and enabled per default in QuiltiX.

❗Adding additional Hydra delegates can, depending on the renderer, be a non-trivial task due to the need of matching USD (and potentially MaterialX) versions for the compiled binaries. Some renderers also need additional configuration for additional features like renderer specific procedurals or shaders.

To register a Hydra renderer plugin the Hydra plugin directory of the renderer needs to be added to the PXR_PLUGINPATH_NAME environment variable. Generally renderers also need their binaries added to the PATH enviornment variable, but there might be additional variables for licensing or additional features.

Below is a non-exhaustive list of install instructions for Hydra renderers.

Arnold

To use Arnold in QuiltiX we require

• Arnold SDK
• A compiled version of arnold-usd

Full Arnold install instructions

The SDK (v7.2.1.0) can be downloaded from here. Extract it to a favoured directory.
To install a compiled version of arnold-usd one can download it from here(v7.2.1.0) or install from source

Afterward couple of enviornment variables need to be set

set PATH=%PATH%;SDK_EXTRACT_DIR/bin
set PXR_PLUGINPATH_NAME=%PXR_PLUGINPATH_NAME%;ARNOLD_USD_DIR/plugin

Karma

To run Karma you need to execute QuiltiX from hython. See here for more information.

It is possible to use additional Hydra delegates, which are available in the Houdini environment.

Changing the active Hydra delegate

The default Hydra delegate can be changed by setting the HD_DEFAULT_RENDERER environment variable to the preferred renderer.

set HD_DEFAULT_RENDERER="GL"

After opening QuiltiX the active Hydra delegate can be changed in the "View" -> "Set Renderer" menu.

Adding custom MaterialX Node definitions

To add custom MaterialX node defintions they can be added by adding the location of the node definition files to the PXR_MTLX_PLUGIN_SEARCH_PATHS environment variable.

Platform support

QuiltiX has been developed with all platforms in mind, but has been developed on Windows. If you see any issues on another platform please open up an issue.

Contributing

We welcome contributions to the QuiltiX! If you'd like to contribute, please follow these steps:

1. Fork the repository.
2. Create a feature branch.
3. Commit your changes.
4. Submit a pull request.

License

QuiltiX is licensed under the Apache License. See LICENSE for more information.