the unity web player

The Future of Web Deployment in Unityjonas echterhoff | [email protected]!Computer Programmer at Unity Technologies

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A quick look at the current state of Web Deployment in Unity

Uberstrike, a popular Unity Web Player FPS MMO on Facebook

The Unity Web Player

• A browser plugin to run Unity content in any supported web browser.!

• Has been part of Unity since Unity 1.0 in 2005.!

• Delivers the highest quality gaming experience possible on the web.

The Unity Web Player

• Bundled with Qihoo 360 Browser in China!

• Integrated by Facebook using custom Facebook SDK.!

• 347 Million installs and counting.!

• Heaviest Growth in Asia, with 42% of current web player users in Asia.

The Web is evolving

• For a long time, plug-ins were the only way to deploy advanced content formats.!

• HTML5 has made more and more of such formats possible without the need for plugins.!

• Browser vendors are starting to steer away from plugins.!

• Google has announced that they plan to discontinue support for NPAPI plug-ins in Chrome.

Now let’s take a look at the new Web Deployment Technology we announced for Unity 5.0

WebGL

• Hardware-accelerated 3D rendering in the browser, without the need to install a plug-in, using JavaScript!

• API is based on OpenGL ES 2.0.!

• Open web standard.!

• Currently implemented in Firefox, Chrome, Internet Explorer and Opera.

WebGL & Unity

• Perfect fit for Unity on the web.!

• We started experimenting with it at a HackWeek two years ago.!

• Mozilla sent an engineering team to our HackWeeks to join the fun.!

• Over the course of a few HackWeeks, we began to see some real potential for this, and started full production.

WebGL & Unity

Unity developers watching presentations at HackWeek

WebGL & Unity

• Now, we are finally ready to show some results!

WebGL & Unity

So, how does this work?

• WebGL is a JavaScript API. To use it all our code needs to be in JavaScript.!

• We need to somehow convert all our code to JavaScript.!

• Unity Engine code, written in C/C++.!

• User scripts, written in C# or UnityScript.

Introducing: emscripten

Introducing: emscripten

• emscripten is a C++ to JavaScript cross-compilation toolchain !

• Uses clang to compile C++ code to LLVM bitcode, and then provides a custom LLVM backend to emit JavaScript as a result.!

• Open-source project started by Alon Zakai from Mozilla.!

• Provides wrappers for common Web APIs.!

• We use emscripten to cross-compile our Unity engine code to asm.js JavaScript.

Introducing: asm.js

• JavaScript is typically JIT-compiled by the browser’s JavaScript engine.!

• The nature of the JavaScript language can make it hard for the JS JIT engine to make the best guesses on optimizations.!

• asm.js is a statically-typed subset of JavaScript, designed to allow a JavaScript engine to AOT compile asm.js code into well-optimized native code.!

• asm.js retains full compatibility with classic JIT JS engines.!

• asm.js has been invented by Luke Wagner at Mozilla.!

• asm.js is currently enabled in Firefox.

Introducing: IL2CPP

• emscripten let’s us compile our engine to JS, but what about user scripts (C#/UnityScript)?!

• Over the course of the past two years, our scripting team has been developing a new code compilation technology codenamed IL2CPP.!

• IL2CPP takes .NET Bytecode (CIL) and generates corresponding C++ source files.!

• These generated C++ source files can then by cross-compiled to JS (with asm.js) by emscripten.

Let’s look at the code conversion process with an example C# script:

That gets compiled into CIL bytecode by mcs:

That gets compiled into C++ code by IL2CPP:

That gets compiled into LLVM Bitcode using clang:

That gets compiled into JavaScript with asm.js by emscripten:

Finally, emscripten will run an optimization and minifcation pass on the JavaScript code.!!The result looks like this:

Unity WebGL add-on early-access in Unity 5.0


• Early-access version of the WebGL add-on will be available for purchase for Unity 5.0.!

• Will allow you to deploy Unity content to WebGL, but will have some feature limitations.!

• Will only support the desktop versions of Firefox and Chrome for now, though other browsers may already work as well.


• Features not supported by WebGL in 5.0 include:!

• Video!

• Runtime Substance generation!

• Networking (WWW class is supported, but no .NET sockets)!

• Microphones and WebCams!

• Script debugging!

• Exception support!

• Threads!

• Scripting will be limited to AOT compilation


• Performance will generally not be as fast as native code running in the Web Player.

WebGL running Basemark X benchmark suite


• Performance will generally not be as fast as native code running in the Web Player.!

• How much slower it is depends on the situation. !

• JavaScript has neither SIMD nor Multithreading capabilities yet.!

• Overall frame rates for content we have tested in WebGL running in Firefox already at least 50% of what they are in the Web Player.!

• You can use the profiler to optimize performance for WebGL just as in any other Unity platform.

Plugin support in WebGL

• You can just write a plugin directly in JavaScript and call functions from that from your C# scripts.!

• You can also just add C++ source files to your project, and call functions from them from your game scripts.!

• You can use Application.ExternalCall or Application.ExternalEval,like you would do in the Web Player.

Unity 5.x and beyond

• We plan to make WebGL a fully supported platform in Unity during the 5.x release cycle. Then we will drop the “early-access” label.!

• We expect to have most of the feature limitations resolved during the 5.x cycle.!

• We also expect that more browsers will support the needed feature set to run Unity WebGL content nicely in the future.


• Unity Web Player is still the most powerful and most widely support solution for deploying Unity content on the web.!

• We plan to keep supporting both the Unity Web Player and WebGL for the future (for at least the 5.x release cycle)!

• Deploy your content using both delivery methods to get the widest possible reach.!

• Longer term, we expect that browser vendors will drop support for plugins and that the Unity Web Player will then become obsolete.


• Microsoft and Apple are working on making WebGL available in Internet Explorer and Safari.!

• WebGL 2.0 is expected in the course of this year, and will have a feature set matching OpenGL ES 3.0.!

• Both SIMD and Multithreading extensions for JavaScript are currently being discussed by browser vendors.

Thanks to the WebGL Team at Unity for their hard work on this:

Jonathan Chambers, Jonas Echterhoff, Gabriele Farina, Ralph Hauwert, Tomas Jakubauskas

Also to the Team at Mozilla for being a great help, and for pushing the technology which makes this possible:

Martin Best, Jukka Jylänki, Vladimir Vukicevic, Luke Wagner, Alon Zakai

?!Q & A!

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