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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
• QuiltiX Plugins
  • Creating a QuiltiX plugin
  • QuiltiX Plugin hooks
• Integrating with your environment
  • Using your own compiled OpenUSD
  • Adding Hydra delegates
    • Arnold
    • Karma
  • Adding custom MaterialX Node definitions
• Platform support
• Contributing
• License

Requirements

QuiltiX requires Python 3.11+ 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/Mac 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@24.03-win-mtlx-1.38.9

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.

QuiltiX Plugins

QuiltiX supports adding Plugins via the environment variable QUILTIX_PLUGIN_PATHS. We are using pluggy in the backend to load them.

Creating a QuiltiX plugin

To create a QuiltiX plugin you need to create a plugin.py file. In this file you need implement one or multiple hooks that QuiltiX provides. Example:

@qx_plugin.hookimpl
def after_ui_init(editor: "quiltix.QuiltiXWindow"):
    # I am printing the QuiltiXWindow
    print(editor)

You also need to implement a plugin_name function returning the name of your plugin. Example:

def plugin_name() -> str:
    return "QuiltiXWindow printer"

If your plugin has the possibility to not be valid (due to missing dependencies or similar) you can implement a is_valid function returning False to avoid it loading entirely. Example:

def is_valid() -> bool:
    if 1==1:
      return False
    else:
      return True

For further reference please take a look at the sample_plugins dir and the tests in tests/test_plugins.py

QuiltiX Plugin hooks

These are the hooks that are currently supported, but there is no harm in adding more. If you would like to add hooks in other parts of QuiltiX to support your features, please open an Issue/PR. The hook specifications live in src/QuiltiX/qx_plugin.py

hook	Purpose
before_ui_init	Building UI funcionality on top of the QuiltiX UI
after_ui_init	Adjusting parts of the internals before the QuiltiX UI startup
before_mx_import	Adjusting things like environment variables before MaterialX gets initialized
after_mx_import	Adjusting MaterialX specific functionality right after it gets imported
before_pxr_import	Adjusting things like environment variables before pxr (OpenUSD) gets initialized
after_pxr_import	Adjusting pxr (OpenUSD) specific functionality right after it gets imported

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

Using your own compiled OpenUSD

To be able to use your own version of OpenUSD for QuiltiX instead of relying on our provided version, you will need to provide some environment variables. Make sure that you append to them!
Essentially you need to add all .dlls to PATH and the pxr python library to PYTHONPATH.

Environment Variable	Path relative to compiled ${USD_ROOT}
PATH	${USD_ROOT}/bin
PATH	${USD_ROOT}/lib
PYTHONPATH	${USD_ROOT}/lib/python

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 environment 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 you need the following:

• Arnold SDK
• A compiled version of arnold-usd

Full Arnold install instructions

Arnold SDK download instructions can be found here. To install arnold-usd one can build from source here.

For Windows you can find a compiled version of hdArnold and the Arnold SDK here with install instructions.

This plugin can be used in USD applications, like QuiltiX, to add the Arnold Hydra delegate.

Download and extract the archive and then add the following paths to the environment:
Arnold/hdArnold/plugin to PXR_PLUGINPATH_NAME
Arnold/Arnold-7.2.5.2-windows/bin to PATH

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.