JSAR: a revolutionary Browser Engine Library designed for Metaverse.

User Manual · DeepWiki

Table of Contents

1. Introduction
2. Overview
   • Request Formats
   • Scripting & Modules
   • 3D Graphics
   • Rendering Backends
   • WebXR Device APIs
   • Multimedia APIs
   • Canvas
   • Classic Rendering
3. Contributing
   • Prerequisites
   • Build from source
4. Loaders

Introduction

✨ Bringing Web Technologies to Life in Metaverse

JSAR is a revolutionary browser engine library designed for the next computing era (Metaverse). It enables you to create immersive Web contents using the modern Web technologies (HTML5, CSS3, TypeScript) and seamlessly integrate them into mainstream 3D engines like Unity, UnrealEngine, and RealityKit.

🌟 Why Choose JSAR?

• 🎯 3D-First Design - Unlike traditional browsers, JSAR is optimized from the ground up for 3D and spatial computing
• 🔧 Easy Integration - Supports multiple rendering backends and platform integrations
• 📱 Cross-Platform Compatible - Supports both Android and macOS platforms
• ⚡ High Performance - A builtin ECS to achieve the GPU-driven renderer for elements
• 🌐 Web Standards Compliant - Supports WebXR, WebGL, Web APIs, and other modern Web standards

Overview

Supported URL Formats to Request

Like the classic Web browser, it supports not only the HTML document, but also lots of formats, such as SVG, 3D models, etc. The following formats is expected to support:

Format	Status	Recommended Use Case
HTML	Partially	Browsing classic Web pages
GLTF	Ok	Displaying 3D models
JPEG/PNG	Ok	Viewing images
SVG	Not started	Displaying SVG images

Scripting & Modules

API	Status	Test Suite
JavaScript	Ok	-
TypeScript	Ok	-
ECMAScript Module	Ok	-
WebAssembly	Ok	-
Web Worker	Ok	-

3D Graphics

API	Status	Test Suite
WebGL1	Ok	https://github.com/KhronosGroup/WebGL/tree/main/sdk/tests/conformance
WebGL2	Ok	https://github.com/KhronosGroup/WebGL/tree/main/sdk/tests/conformance2
WebGPU	Not started	https://github.com/gpuweb/cts

Rendering Backends

The following are supported renderer backends:

Backend	OS	Status	Test Suite
OpenGLES3	Android	Ok	-
OpenGL	macOS	Partially	-
Metal	macOS	Not started	-
D3D11	Windows	Not started	-

WebXR Device APIs

API	Status	Test Suite
Spaces and Reference Spaces	Ok	-
Stereo Rendering	Ok	-
Inputs and Input Sources	Ok	-

Supported Input Sources

Input Source	Status	Target Ray Mode	Gamepad	Profiles
gaze	Ok	gaze	No	-
hand(2)	Ok	tracked-pointer	No	-
main controller	Ok	tracked-pointer/screen	Yes	-
transient	Not implemented	transient-pointer	No	-

Note: Gamepad is not supported in the current version.

Features

Feature	Status	Test Suite
Hit Test	Not implemented	-
Anchors	Not implemented	-
Hand Tracking	Ok	-
Eye Tracking	Not implemented	-
Depth Sensing	Not implemented	-
Face Tracking	Not implemented	-
Body Tracking	Not implemented	-
Environment Probes	Not implemented	-
Light Estimation	Not implemented	-

Multimedia APIs

In Web multimedia, there are the following APIs that JSAR would support:

• Playback: play audio and video, and use Web Audio API to create audio effects.
• Capture: capture audio and video from the device.

Playback

API	Status	Test Suite
HTMLAudioElement	Ok	-
HTMLVideoElement	Not started	-
Web Audio API	Not started	-

Capture

API	Status	Test Suite
MediaDevices	Not started	-
MediaRecorder	Not started	-

Canvas

API	Status	Test Suite
RenderingContext2D	Ok	-
PDFRenderingContext	Not started	-
HTMLRenderingContext	Not started	-

Note: PDFRenderingContext and HTMLRenderingContext are introduced by JSAR, which is used to customize the PDF and HTML rendering.

Classic Rendering

API	Status	Test Suite
DOM API	Partially	-
HTML5	Partially	-
CSS3	Partially	-
Web Component	Not started	-

Contributing

To contribute to the project, you need to follow the steps below to build this project from source.

Prerequisites

• Node.js v18.16.1
• Rust v1.70.0 or later

And you need to add the following targets to your Rust toolchain by your need:

$ rustup target add aarch64-linux-android
$ rustup target add aarch64-apple-darwin
$ rustup target add x86_64-apple-darwin
$ rustup target add x86_64-pc-windows-msvc

Build from source

Firstly, you need to install the dependencies and build the JSAR JavaScript bundle which is used in the runtime.

$ npm install && make jsbundle

Then you can build the runtime library:

$ make darwin    # for macOS universal library
$ make android   # for Android-aarch64 library

If you want to do a clean build, you can run:

$ make darwin CLEAN=yes

Supported parameters:

• CLEAN: Clean the build directory before building.
• RELEASE: Build the release version of the library.
• INSPECTOR: Enable the inspector.

Loaders

The loaders are more convenient way to integrate JSAR into your applications, the following loaders are planned to be developed:

Loader	Status	Description
jsar-loader-unity	Ok	Integrates JSAR into Unity applications
jsar-loader-unreal	Not started	Integrates JSAR into Unreal Engine applications
jsar-loader-visionos	Not started	Integrates JSAR into visionOS applications

To develop a new loader, you could see the Embedder API Documentation for more details.