Unreal Engine 5, [UE5 Developer Availability 2022-04-05]

Given how long The Finals has been playable for, I assume Embark are not iterating off last year's Kajiya GI experiments. Thought this was worth posting though, as it show that they're a studio to watch in terms of playing around with their own tech (if The Final's level of networked destruction wasn't enough to show off their technical proficiency).
They were formed by a bunch of smart ex-EA SEED/Frostbite folks that I worked with before coming to Epic. So yeah, they have lots of super-talented rendering folks and I'm excited to see what they do with their various projects!
 
Given how long The Finals has been playable for, I assume Embark are not iterating off last year's Kajiya GI experiments. Thought this was worth posting though, as it show that they're a studio to watch in terms of playing around with their own tech (if The Final's level of networked destruction wasn't enough to show off their technical proficiency).

https://github.com/EmbarkStudios/kajiya/blob/main/docs/gi-overview.md

Also, when they first formed they spend three weeks knocking up a landscape demo in UE4. It's really nice looking. ARC Raiders will be one pretty game even without leveraging Lumen/Nanite.


Kajiya is for a Roblox/Dreams/Etc. type "make your own stuff" game they're working on long term. They were considering open sourcing the whole engine eventually, but one of the primary programmers went off to make Tiny Glade, which abuses restir to no end to get realtime RT GI working all the way down to somewhat older integrated laptop GPUs


So I don't know where the Roblox like project is anymore. I do know that since all the RT stuff is Nvidia plugins, which aren't fast, and both Arc and Finals are fast paced FPSes launching on consoles that getting that stuff to work is definitely not a priority.
 
I see "better VRAM management" is on their roadmap for Unreal Engine 5.4.

Now, I would say current UE5 titles do not need much VRAM thanks to Virtual Texturing which is definately a great thing. However, I would say the VRAM management itself is not particularily good. Specifically, it has the issue that the VRAM fills up over time and slowing it down. So when you are at point A at time X in the game and you come back to it at time Y then it might run a lot slower. I have observed this in the Matrix demo on a tight framebuffer. This "slow killer" as I call it, is arguably a sign of bad garbage collection or something else. It is super annoying because you set your graphics setting carefully, only to find out it runs a lot worse for no apparent reason later. Also texture streaming is sloooow, as Alex said in his video.

So I guess this is what they plan to improve, which I'm pretty happy about. I think UE 5.4 will be a game changer, especially if it truly managemes to improve multi-threading and RT performance.

Also, I'm wondering if https://portal.productboard.com/epi...ublic-roadmap/c/1250-nanite-optimized-shading means they are going to use Mesh Shading properly this time. Would be amazing if true, it could lead to a noticeable performance boost on supported cards, as demonstrated by Alan Wake 2.

(Note: I'm aware Nanite is using mesh shader for geometry larger than a pixel. Sadly though, it doesn't do anything. In benchmarks, the 5700XT performs equal to a 2070 Super, so no performance improvement can be observed, which means Mesh Shading is pretty much useless in its current implementation in UE. So I really hope to see improvements there)
 
Last edited:
To recap:
-Software Lumen has lots of screen space elements, especially around emissive lights and ambient occlusion, it also has light leaks and light boiling in areas with secondary bounces/emissive lights.
-Hardware Lumen can be modded in Fort Solis for great visual uplift
-There is lots of CPU related problems, Single Threaded bottlenecks, GPU underutilization, PSO stutters and traversal stutters.
 
Good video as usual. For me, I want to see UE5 games exceed CP/AW2 at similar performance. Until then it’s a land of promises.
Is this a realistic expectation?

Is it reasonable to think that with time, AAA UE5 titles will start to match exceed the best looking titles from AAA studios, using custom engines?

What about UE4?
How do the best looking UE4 titles compare to custom engines?
Gears 5 vs COD? ( probably a tie imho )
 
Also, I'm wondering if https://portal.productboard.com/epi...ublic-roadmap/c/1250-nanite-optimized-shading means they are going to use Mesh Shading properly this time. Would be amazing if true, it could lead to a noticeable performance boost on supported cards, as demonstrated by Alan Wake 2.
So Nanite is a deferred renderer with a visibility buffer pre-pass. In a classic deferred renderer, you have G-buffer generation pass which will encode screen space information of the materials with a separate lighting pass hence the technique being commonly known as deferred lighting (lighting evaluation is deferred until after G-buffer generation) and both of those passes are done using pixel shaders on older hardware. Ever since the introduction of compute shaders, many modern deferred renderers moved their lighting pass from pixel shaders to compute shaders. During that time, real-time graphics rendering was exploring the concept of deferred texturing (short for a deferred texture sampling system) where we generate a thin visibility buffer to eliminate even more overdraw costs earlier in the rendering pipeline ...

Nanite's rendering system can currently be described as a combination of deferred texturing/visibility buffer (PS/CS) + G-buffer/material evaluation (PS) + deferred lighting (CS). Their long term goal is to change their G-buffer/material evaluation pass from using pixel shaders (PS) into using compute shaders (CS) ...
(Note: I'm aware Nanite is using mesh shader for geometry larger than a pixel. Sadly though, it doesn't do anything. In benchmarks, the 5700XT performs equal to a 2070 Super, so no performance improvement can be observed, which means Mesh Shading is pretty much useless in its current implementation in UE. So I really hope to see improvements there)
The only fancy thing that Nanite is doing with mesh shaders is that it outputs some per-primitive attributes. It does not even make use of amplification shaders. Cluster culling is handled in a compute shader. The vertex shader fallback gets by with unrolling the meshlets into indirect instanced draws ...
 
It does not even make use of amplification shaders. Cluster culling is handled in a compute shader. The vertex shader fallback gets by with unrolling the meshlets into indirect instanced draws ...
Worth noting that it doesn't use amplification shaders because it doesn't need to. Nanite is already doing something more sophisticated than what basic mesh shaders do, namely hierarchical LOD and culling with persistent threads. And Nanite tessellation/displacement goes even a step further. Work graphs should in theory be a good fit here but ?? on IHV drivers and performance still.

There's nothing wrong with mesh shaders as a tool but so help me if you guys start the "if using an API feature doesn't give you a performance benefit in my test you are using it wrong" nonsense again I'm gonna lose it ;)
 
Last edited:
Worth noting that it doesn't use amplification shaders because it doesn't need to. Nanite is already doing something more sophisticated than what basic mesh shaders do, namely hierarchical LOD and culling with persistent threads. And Nanite tessellation/displacement goes even a step further. Work graphs should in theory be a good fit here but ?? on IHV drivers and performance still.
GPU work graphs indeed looks like a good fit to implement Nanite's ring buffer since it would grant some forward progress guarantees for doing inter-workgroup barrier synchronization ...
There's nothing wrong with mesh shaders as a tool but so help me if you guys start the "if using an API feature doesn't give you a performance benefit you are using it wrong" nonsense again I'm gonna lose it ;)
Oh, I suspect some of us here are all too aware! 😭
 
Jusant is a perfectly fun game, especially if you happen to have Gamepass at the moment (just ending for me but I should be done with the game like, tonight).

It's an interesting showcase of UE5 in that it's not targeting super high end visuals, but the super clean art design lets you get a good look at the technical features. I put TSR on to see where it's at, and it's much improved over previous versions. Relatively low cost, aliasing increases while under heavy camera motion of course but that's all these upscaling features. Otherwise it's a very solid competitor with very little in the way of obvious movement breakup on primary geometry. Of course it falls down completely with dramatic shading changes, you can see the shadows glitch out as your character moves in anything but a straight line, and while they're cleaned up quickly it's still very obvious, a reminder that temporal upscaling has variable rate shading as it's obviously better but more development time cost partner out there.

It's also a great showcase of Lumen, and it's limitations. Going with software only Lumen is fine as the art style is diffuse only without much in the way of sharp features, so most of the time the resolution limitations aren't noticeable at all. The thing that is noticeable is the light bounce limitations, every cave is either pitch black very quickly (and the game is like half caves) or there's a lightsource in the cave which is very often. To get around these limitations the artists have put wide area lights faking more GI into cave exits all over the place, abusing the virtualized shadow maps until they have obvious overlap issues, but otherwise they're done pretty well and serve to brighten up otherwise pitch black caves. As this wouldn't work well in a non fixed time of day scenario though it seems an obvious limitation on Lumen in open world type games.

I'll see if I can get some screenshots tonight.
 
Been playing more Ark with my wife and I gotta say... it really continues to make me sit back and say "wow this looks pretty great", even with pretty mundane early game builds and such. Can't wait to see what some of the skilled builders come up with.

While shadow foliage flicker is still an obvious issue (particularly frustrating for me as you might expect, heh), they've been patching quickly and some of the other issues have gotten a bit better and performance has improved a bit. Certainly moving in the right direction.
 

Attachments

  • Screenshot 2023-10-31 233522.png
    Screenshot 2023-10-31 233522.png
    7.1 MB · Views: 48
  • Screenshot 2023-10-31 233629.png
    Screenshot 2023-10-31 233629.png
    7.1 MB · Views: 48
  • Screenshot 2023-10-31 233747.png
    Screenshot 2023-10-31 233747.png
    4.9 MB · Views: 48
Back
Top