Hydra USD PySide Viewer

This project is a simple USD (Universal Scene Description) viewer built with PySide6 and integrated with Hydra for rendering. It includes a timeline widget for animation playback, inspired by BigRoy’s example on Gist.

Features

•	Load and display USD files
•	Control animation playback with a timeline widget
•	Adjust frames per second (FPS) for playback

Setup Instructions

Prerequisites

•	Python 3.11 (or adjust as needed)
•	PySide6
•	PyOpenGL
•	OpenUSD (built from source)

Step-by-Step Setup

1. Clone the Repository

git clone https://github.com/your-username/hydra-usd-pyside-viewer.git
cd hydra-usd-pyside-viewer

2. Setup Python Environment

This project uses pyenv for managing the Python version. You can set up pyenv as follows, but it’s optional.

pyenv install 3.11.5
pyenv virtualenv 3.11.5 hydra-usd-pyside
pyenv activate hydra-usd-pyside

3. Install Dependencies

pip install -r requirements.txt

4. Build OpenUSD

Follow the instructions on the OpenUSD GitHub repository to build USD from source. Use the --build-monolithic option to ensure all necessary components are included.

git clone https://github.com/PixarAnimationStudios/OpenUSD.git
cd OpenUSD
python build_scripts/build_usd.py /opt/local/USD --python --build-monolithic

5. Update env_setup.py

Modify the USD_INSTALL_PATH variable in env_setup.py to point to your USD build location.

# Define the USD installation path
USD_INSTALL_PATH = '/opt/local/USD'

6. Run the Application

python src/main.py

Usage

•	Play Animation: Use the play button on the timeline widget to start/stop the animation.
•	Adjust FPS: Use the FPS control to change the playback speed.
•	Navigate Frames: Use the slider or frame input boxes to jump to specific frames.

Project Structure

•	env_setup.py: Sets up the necessary environment variables for USD.
•	src/main.py: Main application script.
•	timeline.py: Contains the timeline widget and playback control logic.
•	requirements.txt: List of Python dependencies.

Notes

•	Ensure the USD build location is correctly set in env_setup.py.
•	The project uses pyenv for environment management, but it’s optional. You can use any Python environment setup that 

Code Borrowed from BigRoy here: https://gist.github.com/BigRoy/5ac50208969fdc69a722d66874faf8a2