USD Viewer App Template

Overview

The USD Viewer App Template is designed to provide a robust starting point for developers looking to create streaming Omniverse Applications. This template showcases an RTX viewport, app streaming, and messaging support.

Use Cases

The USD Viewer Template is perfectly suited for streaming into a front end client.

Usage

Getting Started

To get started with the USD Viewer template, ensure your development environment meets the prerequisites outlined in the top-level README.

NOTE: Example commands should be executed in powershell in Windows and terminal in Linux.

⚠️ Important: Before proceeding with the cloning step, ensure that Git Large File Storage (Git LFS) is installed on your system. To verify this, run the following command in your terminal:

git lfs --version

If the command returns a version number, Git LFS is installed correctly. If not, you will need to install Git LFS. You can download and install it from the official website here.

Cloning the Repository

git clone https://github.com/NVIDIA-Omniverse/kit-app-template.git
cd kit-app-template

Create New Application

Note for USD Viewer : This application requires extra and setup extensions to function as intended. These extensions handle the configuration within application, communication, layout, and other settings. During Application configuration, you will be prompted for information about these extensions.

NOTE: Feel free to use default values for testing purposes.

Linux:

./repo.sh template new

Windows:

.\repo.bat template new

NOTE: If this is your first time running the template new tool, you'll be prompted to accept the Omniverse Licensing Terms.

Follow the prompt instructions:

? Select what you want to create with arrow keys ↑↓: Application
? Select desired template with arrow keys ↑↓: USD Viewer
? Enter name of application .kit file [name-spaced, lowercase, alphanumeric]: [set application name]
? Enter application_display_name: [set application display name]
? Enter version: [set application version]

For each required extension you will be prompted [display name] -> [extension name]:

? Enter name of extension [name-spaced, lowercase, alphanumeric]: [set extension name]
? Enter extension_display_name: [set extension display name]
? Enter version: [set extension version]

NOTE: You will need to repeat above steps for each extension.

Build and Launch

Note that the build step will build all applications contained in the source directory. Outside of initial experimentation, it is recommended that you build only the application you are actively developing.

Build your application using the provided build scripts:

Linux:

./repo.sh build

Windows:

.\repo.bat build

If you experience issues related to build, please see the Usage and Troubleshooting section for additional information.

Launch your application:

Linux:

./repo.sh launch

Windows:

.\repo.bat launch

? Select with arrow keys which App would you like to launch: [Select the desired viewer application]

NOTE: The initial startup may take a 5 to 8 minutes as shaders compile for the first time. After initial shader compilation, startup time will reduce dramatically.

Default Launch State

By default, the USD Viewer template application opens with an empty viewport.

This is the intended behavior. The USD Viewer template application is designed as a base for displaying content either locally or over a streaming connection (See the Local Streaming section below).

To display content in the desktop application, you can pass an argument to the repo launch command to load content on startup. The USD Viewer template includes sample assets for this purpose. Let's load the stage01.usd sample asset by providing the full path to the /app/auto_load_usd argument.

Linux:

./repo.sh launch -- --/app/auto_load_usd='${omni.usd_viewer.samples}/samples_data/stage01.usd'

Windows:

.\repo.bat launch -- --/app/auto_load_usd='${omni.usd_viewer.samples}/samples_data/stage01.usd'

Testing

Applications and their associated extensions can be tested using the repo test tooling provided. Each application template includes an initial test suite that can be run to verify the application's functionality.

NOTE: Testing will only be run on applications and extensions within the build directory. A successful build is required before testing.

Linux:

./repo.sh test

Windows:

.\repo.bat test

Create Custom Extension

Linux:

./repo.sh template new

Windows:

.\repo.bat template new

Follow the prompt instructions:

? Select what you want to create with arrow keys ↑↓: Extension
? Select desired template with arrow keys ↑↓:: [choose extension template]
? Enter name of extension [name-spaced, lowercase, alphanumeric]:: [set extension name]
? Enter extension_display_name:: [set extension display name]
? Enter version: [set extension version]

Adding Extension to .kit File

Importantly For an extension to become a persistent part of an application, the extension will need to be added to the .kit file.

[dependencies]
"extension.name" = {}

Build with New Extensions

After a new extension has been added to the .kit file, the application should be rebuilt to ensure extensions are populated to the build directory.

Packaging and Deployment

For deploying your application, create a deployable package using the package command:

Linux:

./repo.sh package

Windows:

.\repo.bat package

By default, the package command will name the package based on the name value contained in the repo.toml file at the root of the repository. By default, this value is set to kit-app-template. Modify this value to set a persistent package name for your application.

Alternatively, you can specify a package name using the --name flag:

Linux:

./repo.sh package --name <package_name>

Windows:

.\repo.bat package --name <package_name>

This will bundle your application into a distributable format, ready for deployment on compatible platforms.

⚠️ Important Note for Packaging: Because the packaging operation will package everything within the source/ directory the package version will need to be set independently of a given kit file. The version is set within the tools/VERSION.md file.

Launching a Package

Applications packaged using the package command can be launched using the launch command:

Linux:

./repo.sh launch --package <full-path-to-package>

Windows:

.\repo.bat launch --package <full-path-to-package>

NOTE: This behavior is not supported when packaging with the --thin flag.

Containerization (Linux Only)

Requires: Docker and NVIDIA Container Toolkit

The packaging tooling provided by the Kit App Template also supports containerization of applications. This is especially useful for deploying headless services and streaming applications in a containerized environment.

To package your application as a container image, use the --container flag:

Linux:

./repo.sh package --container

You will be prompted to select a .kit file to serve as the application to launch via the container entrypoint script. This will dictate the behavior of your containerized application.

For example, if you are containerizing an application for streaming, select the {your-app-name}_streaming.kit file to ensure the correct application configuration is launched within the container.

NOTE: If creating a container for a NVIDIA Cloud Functions (NVCF) based deployment, select the {your-app-name}_nvcf.kit file to ensure the proper settings are used for that platform.

Similar to desktop packaging, the container option allows for specifying a package name using the --name flag to name the container image:

Linux:

./repo.sh package --container --name [container_image_name]

Launching a Container

Applications packaged as container images can be launched using the launch command:

Linux:

./repo.sh launch --container

If only a single container image exists, it will launch automatically. If multiple container images exist, you will be prompted to select the desired container image to launch.

Local Streaming

During the creation of a new application, you can enable streaming by selecting the desired streaming layer(s) for your application. Selecting the Omniverse Kit App Streaming (Default) layer will create a {your-app-name}_streaming.kit which we will use for local streaming. This file inherits from the base application and adds necessary streaming components like omni.kit.livestream.webrtc. To try local streaming, you need a web client to connect to the streaming server.

1. Clone Web Viewer Sample

The web viewer sample can be found here

git clone https://github.com/NVIDIA-Omniverse/web-viewer-sample.git

Follow the Quick Start instructions in the README to install the necessary dependencies.

2. Start the streaming Kit Application

⚠️ Important: Launching the streaming application with --no-window passes an argument directly to Kit allowing it to run without the main application window to prevent conflicts with the streaming client.

Launch and stream a desktop application:

Linux:

./repo.sh launch -- --no-window

Windows:

.\repo.bat launch -- --no-window

Select the {your-app-name}_streaming.kit and wait for the application to start

Launch and stream a containerized application:

When streaming a containerized application, ensure that the containerized application was configured during packaging to launch a streaming application (e.g., {your_app_name}_streaming.kit).

Linux:

./repo.sh launch --container

If only a single container image exists, it will launch automatically. If multiple container images exist, you will be prompted to select the desired container image to launch.

NOTE: The --no-window flag is not required for containerized applications as it is the default launch behavior.

3. Start the Streaming Client

Follow the Quick Start instructions in the web-viewer-sample README to start the streaming client (with Web UI overlay for messaging) and connect via a Chromium-based browser. You should see the streaming client connect to the running Kit application.

Additional Learning