Please explain UE4 & HTML5 (for dummies)

Could someone with a knowledge of this stuff just give a quick rundown on what is happening behind the scenes when you deploy/run a UE4 project for HTML5? I have absolutely no clue in general regarding web programming, but am super interested in the potential of this.

So basically:

  • Does some process need to be running on the web server? Or is emscripten somehow able to compile UE4 in its entirety, along with all its dependencies, to JavaScript, and everything runs client side? That just seems crazy to me, but then again I have no idea.
  • Aside from performance, what are the major limitations of running UE4 in a browser? Fundamentally I mean, as opposed to things which just aren’t supported as yet.
  • If you build an HTML5 project, does that mean you can expect it to run (for the most part anyway) in a browser on any capable device, without having to worry about a lot of the things you need to worry about if deploying directly to various mobile devices?
  • How does networked multiplayer fit in with this. Does a UE4 game server not care what platform its clients are on? Can a listen server even be running on an HTML5 client?

Sorry for the (probably dumb) questions, and thanks for educating!

Okay… addressing your points in order:

Emscripten does indeed compile the entire UE4 project into Javascript, which makes for large downloads but removes the need for any server-side support.

The main restriction is that the browser is running WebGL (OpenGL ES 2.0 variant), which just isn’t as capable as a full desktop OpenGL/DirectX. The capabilities are a lot closer to that of standard mobile devices.

I’ve still got to try it on different mobile devices, really just been using it to build a tool targeting desktop.

The server doesn’t care what platform the client is running, but I’ve not tried networking on HTML5 UE4. It should be possible though, there are browser-based technologies such as Websockets which can open full duplex connections.

(sorry bad english) Hello, I do some screenshots for show how unreal engine 4 works on HTML5 (x32 and x64)
First, 32 bit web explorer could have an out of memory issue but not all the time… I tested on Firefox 40.0a2 64 bit (beta).
One thing to know : There is anything to do specialy for make a scene working on HTML5. What you have when you run on your computer is what you have on web exmplorer (cursor, key binding, movements, camera is different, in the scene sci-fi bunker at the end of the traveling you never come to a free view)

Okay so there is some screen shot :

So, field of depth works very fine.
Cubic artifacts, Don’t know where that come from… I suspect some extra map compression (like glossmap or roughtmap… normal map look nice on suntemple…)
no EMISSIVE light bloom

Remember it is rendered on Firefox… =)
Nice bloom reflected light here ! Maybe too much.
Normal map look nice, A little to soft but it is here.
Always this ugly artifacts, so strange…
EDIT : that artifacts seems to come from the detail normal map =/

You can see here, lights are computed differently between html5 and pc.
In fact, emissive not working.
you’ll see after on sun temple’s screenshots but reflection not working too.
EDIT : And no decals… That could be problematic.

Oh look that !!! It’s amazing… And it’s on web (local)

Now, the sun temple !

Yeah, for me the big probleme who need a fix for now… Light reflection come from nowhere… hum, in fact, this is the position of the sun on the map, but “reflection” don’t care about walls…
This red effect look strange but it is present on PC too so…

That looks soooooo nice \o/
Some lights reflect works fine !
Cubemaps works fine too, looks that chrome effect !

HEYYY Eye adaptation works fine !!

There is a difference between 32 bit and 64 bit web explorer, 32 bit have not bloooom.


I run always at 60 FPS (GTX 760, AMD FX 8320 8 cores, 16 Go DDR3)

My opinion, there is so amazing, just know that is rendered on a web page is absolutly… wow… If you take care about optimisation (for loading ressources) the possibilities are realy impressive !
Take this way Epic, you are EPIC o/

@Molt. Thanks, really appreciate your answers. Was starting to wonder how 300 people could have read the thread and all be as clueless as me!

@Klemorius. Yep I agree, I find it really impressive too. Looking forward to seeing what people do with UE4 HTML5.

I dreamed about creating a full-and-dynamicly-3D-portfolio =D
The one biggest problem I’ll see : Load a new 3D file without recook… hmm…
Another exemple : Architecture project tour, mansion, museum, etc !
And why not an “AI” like a virtual girl (or guy…) for assisting web users on search informations, etc… A virtual google sexy-girl ! (or guy…)
A virtual social room ?
Or a game…