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Comment by astlouis44 | Hacker News Reader

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astlouis44

You can also build Unreal Engine 5 applications for WebGPU as well! See demos linked below:

https://simplystream.com/demos

Edit: These demo should load faster, but use WebGL:

https://topdown.tiwsamples.com/

https://vehiclegame.tiwsamples.com/

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More like you can wait for loading Unreal Engine 5 applications for WebGPU today ;)

The car configurator demo loads a 117 MBytes WASM blob and then hundreds of tiny files between a few hundred bytes to a few KBytes, both extremes are worst case for a web application, it's quite hilarious really.

The demo didn't finish loading while writing this comment, and it doesn't look like the loading of those tiny files will ever end...

Yeah but the fact is that it works today, and will only get better and faster with time.

I bet there's a lot of cheap wins by bundling all those tiny files in a few bigger ones. But minimizing the WASM blob for a humongous native engine like Unreal Engine 5 sounds like a real challenge. Even when this is reduced by 90% it's still 10x bigger than Unity's web output, which is 10x bigger than a specialized WASM game engine designed for the web as "first class citizen".

I have higher hopes for the web people (like PlayCanvas, Babylon, threejs, etc...) writing a proper WASM game engine by "scaling up" their experience of building browser rendering engines, than the traditional "native game engine" people "scaling down" to web requirements (especially when it comes to time needed to start into the game - the entire asset loading system of native engines needs to be rebuilt from scratch for this).

We've actually managed to reduce the WASM runtime for UE5 to just 8MB compressed.

In regards to downloading assets, we've built out an asset streaming system to address this. It allows you to dynamically load in just what you need, when you need it, while everything else that isn't needed right away can be fetched at runtime.

Introducing the cdn of pre built wasm blobs...

I remember the experience of Unreal Engine demos compiled to asmjs a decade ago being more or less the same, taking absolutely forever to load before anything happens. It doesn't feel like much progress has been made on that front.

Try these demos instead (Unreal Engine using WebGL 2.0)

https://vehiclegame.tiwsamples.com/

https://topdown.tiwsamples.com/

Those aren't as bad, about 20 seconds to get going from a cold cache. Car Configurator is incredibly slow though, I timed it at about 8 minutes to load from scratch and when it finally got there it was unusably laggy until I refreshed and let it start again with a pre-warmed cache. According to Chromes internal task manager the CarConfig tab is continuously using about 500% CPU (i.e. five entire cores) and 5GB of RAM despite very little going on in the demo. This is on a current-gen desktop processor.

That's pretty neat, not much in the way of progress bar for me but they load in about 30 seconds. And it seems a little choppy at times but playable. Reminds me of late stage flash era games.

> Yeah but the fact is that it works today, and will only get better and faster with time.

And your assumption is based on what exactly?

WASM + WebGPU don't magically make the whole game, its assets and the engine it uses appear on your computer.

The demo didn't finish loading on a 4090 after 5 minutes...

Which demo did you try? The car configurator? Also if you're using Firefox, WebGPU isn't supported there yet, so I recommend trying using a Chromium browser.

DevTools will most likely help with debugging.

In my case, several of the WebGPU demos on https://simplystream.com/demos fail (while keeping on falsely showing "Loading") with the error message (in DevTools):

"WebGPU requestDevice failed, trying low spec DOMException: Failed to execute 'requestDevice' on 'GPUAdapter': Required limit (64) is greater than the supported limit (32)."

Was using latest Chrome

Didn't work

Honestly Unreal is incredibly suspect in these kinds of applications. Unreal's biggest hallmark is the incredible amount of shaders it generates (thousands for a simple scene) which leads to constant shader compilation delays and stutters even on desktop.

I can't imagine it being good in a web scenario where you can't even precompile.

I like the portability aspect, but between the microstutters, broken textures, and visual glitches, I'm not particularly impressed by these. I kind of feel like Java did this in the browser ten years ago, albeit at a lower resolution.

I guess it still needs work. It's not even available yet on Firefox, but I expected Chrome to work at the very least.

Edit: oh, GPU support doesn't work on Linux, that explains the weirdness. Guess I'll wait for either Firefox or Chrome to release their final releases before I start experimenting with this!

Unreal is a bloated way to develop WebGPU projects for the web. PlayCanvas is a sensible solution if your target is web.

Demos - Cesium crashes my phone.

Edit. Car config the same

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