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

[Andrew Lauritzen]

Still, pretty good that those are the main issues other than a few vsm tiles not getting drawn in fast enough:

You talking about the artifacts at ~0:40 ish? VSMs don't throttle new page data from directional lights at all so it's not an "in time" kind of thing. Something more significant seems to be awry there like an improperly-sized page pool perhaps. That said, in 5.4 there is some automatic mitigation for those kinds of content issues so I'm still a bit unsure as to what the problem is there. Given this is presumably some fan site grabbing content from the marketplace and just dragging sliders up though it's certainly possible they just blew past a bunch of those safeguards and are overflowing various buffers and not seeing or addressing the resulting log warnings.

Watching a bit more into the demo it does seem like they have probably improperly sized the VSM page pool and/or the Nanite pools for that resolution/settings. Many of the issues don't happen in the 1440p setup for instance. There's no reason artifacts like those in the videos should ever happen with properly set up scalability settings.

On straight architectural edges LOD pops become obvious,

Where are you referring to in the video curiously?

limited light bounces cause semi closed off areas to get incredibly dark

There are definitely some limitations on that front and some energy is indeed lost if you compare to that path tracer. That said, people often conflate this with the perception side; in reality interiors often are *much* darker than exteriors on a sunny day if you measure the radiance. Because of how our eyes and perception work though, we don't really perceive them that way. HDR photography and similar make heavy use of stuff like local tone mapping/exposure to adjust this and UE does have some local exposure controls (see https://dev.epicgames.com/documentation/en-us/unreal-engine/auto-exposure-in-unreal-engine), but that part of the pipeline does require a fair amount of expertise to set up well, especially across a wide range of both HDR and SDR outputs and platforms. I expect both aspects of this will continue to evolve over time though as it's as much an artistic question as a correctness one.

 

[Boss]

This level art walkthrough shows issues UE5 currently faces. On straight architectural edges LOD pops become obvious, limited light bounces cause semi closed off areas to get incredibly dark, I'm also pretty sure there's even faked lights in the interior to make up for a lack of light bounces. Still, pretty good that those are the main issues other than a few vsm tiles not getting drawn in fast enough:

From this, perhaps the 4090 won't be able to stay above 60fps at 1440p native which is wild.

 

[DegustatoR]

From this, perhaps the 4090 won't be able to stay above 60fps at 1440p native which is wild.

It's unable to do that in the UE5 titles we already have (like HB2). Hardly news.

 

[Shifty Geezer]

Watching a bit more into the demo it does seem like they have probably improperly sized the VSM page pool and/or the Nanite pools for that resolution/settings. Many of the issues don't happen in the 1440p setup for instance. There's no reason artifacts like those in the videos should ever happen with properly set up scalability settings.

Sounds like Epic could really do with some case studies, taking games with issues and tweaking the settings to show 1) UE5 isn't at fault and 2) Best practice for devs to avoid such issues. It must be frustrating having people criticising the tool when they don't use it right.

 

[Andrew Lauritzen]

Sounds like Epic could really do with some case studies, taking games with issues and tweaking the settings to show 1) UE5 isn't at fault and 2) Best practice for devs to avoid such issues. It must be frustrating having people criticising the tool when they don't use it right.

I mean, it's in the documentation (https://dev.epicgames.com/documentation/en-us/unreal-engine/virtual-shadow-maps-in-unreal-engine)

When it's games making these sorts of mistakes it's more frustrating and actionable. At this point I don't really mind when it's just some enthusiast website or similar downloading marketplace assets that doesn't really know how to use the engine at all beyond that. Certainly it's great the more we can make it work perfectly across a wide range of situations out of the box with minimal experience required but I think demos like this being mostly okay are an indication that it has progressed a long way on that front. Before getting this sort of lighting result would have required quite a bit of work and expertise, so it's easier for me to look past the few smaller issues, especially when they show up mostly because they cherry picked a few scalability settings (i.e. resolution) to modify but didn't really due the proper diligence beyond that.

 

[Frenetic Pony]

You talking about the artifacts at ~0:40 ish? VSMs don't throttle new page data from directional lights at all so it's not an "in time" kind of thing. Something more significant seems to be awry there like an improperly-sized page pool perhaps. That said, in 5.4 there is some automatic mitigation for those kinds of content issues so I'm still a bit unsure as to what the problem is there. Given this is presumably some fan site grabbing content from the marketplace and just dragging sliders up though it's certainly possible they just blew past a bunch of those safeguards and are overflowing various buffers and not seeing or addressing the resulting log warnings.

I'd hesitated to even mention it as I'd never seen it before, so figuring yeah maybe it was just content issues

Where are you referring to in the video curiously?

Re-watching it, and nope! I'd seen it before in the video below (full size is easier), you can see it center frame right at the marked time, but in the Japanese level asset it's just another shadow pop. The most egregious version I'd seen of this is in an isolated, World of Warcraft style art asset, however now that I type it out I'm wondering if these assets are just undertesselated, an overly large meshlet vs screen space size seems like it could cause popping issues like this:

There are definitely some limitations on that front and some energy is indeed lost if you compare to that path tracer. That said, people often conflate this with the perception side; in reality interiors often are *much* darker than exteriors on a sunny day if you measure the radiance. Because of how our eyes and perception work though, we don't really perceive them that way. HDR photography and similar make heavy use of stuff like local tone mapping/exposure to adjust this and UE does have some local exposure controls (see https://dev.epicgames.com/documentation/en-us/unreal-engine/auto-exposure-in-unreal-engine), but that part of the pipeline does require a fair amount of expertise to set up well, especially across a wide range of both HDR and SDR outputs and platforms. I expect both aspects of this will continue to evolve over time though as it's as much an artistic question as a correctness one.

Oh I wasn't complaining about the interior, I mean better ray guiding would help with interiors certainly not needing fake lights, but the contrast there is fine. I was more pointing out the opening of the walkthrough (time marked video below) with the covered alleyway looking quite dark despite being outside in the middle of the day:

It reminds me of the issues offline first had with path tracers. Monsters University was Pixar's first path traced feature, but you can see the lighting is a bit flat, and something doesn't look right, notice the giant shift in contrast on the right hand brick building, how dark those 2 trees make the upper part vs how bright the sunlight bounce makes the lower:


When Disney Animation switched over to their "Hyperion" Path Tracer for Big Hero 6 they wanted lighting good enough to match photographic reference, and found it took 10 bounces to really get there. But I'd say the difference does stand out, even out in broad daylight everything looks "right", the broad areas have enough light bounce to average themselves out, while corner like bus interior on the left and overhang on the right are where contrast starts blowing out:

 

[Andrew Lauritzen]

That's a weird one but I don't think it has anything to do with geometry actually; to me it looks like TSR/TAA/DLSS/whatever is losing it's history all of a sudden for some reason. Could be due to some weird sequencer setup or some other bug, but definitely mostly looks like it pops to aliased/specular, then reconverges over the next bunch of frames. The fact that it all "pops" on the same frame would also be unexpected for a geometric effect with Nanite.

... I'm wondering if these assets are just undertesselated, an overly large meshlet vs screen space size seems like it could cause popping issues like this

It shouldn't for what it's worth. Nanite picks cluster LODs based on a conservative error metric over the cluster triangle edge lengths. Large triangles can blow out cluster bounds and reduce culling efficiency, but should not produce pops. This is part of the real improvements of Nanite over previous systems that relied more on even base mesh tessellation or subdivision to produce appropriate screen sizes. Nanite was meant to handle arbitrary triangle soups well from the beginning.

Oh I wasn't complaining about the interior, I mean better ray guiding would help with interiors certainly not needing fake lights, but the contrast there is fine. I was more pointing out the opening of the walkthrough (time marked video below) with the covered alleyway looking quite dark despite being outside in the middle of the day:

Yeah probably some lost GI but in that particular case it looks more like the majority of the light in the shadows there should be coming from the skylight (rather than bounced off the buildings or similar), so perhaps that is not set up appropriately or is being improperly occluded for some reason. Probably also some local exposure/tone mapping things too though.

No doubt more bounces can certainly help but there are obviously diminishing returns/effects as you increase the count, especially in scenes that are mostly opaque.

 

[RobertR1]

@Andrew Lauritzen something to think about internally. This Eternal Descent game is making headlines for making systems crash esp on intel cpu's.

So I had a deeper look into it to see what's going on. Firstly, on my 14700k tuned with manually set voltages, it's still pulling 300w. Not an issue for me as I have deep knowledge of platform tuning. The problem you'll have here is a few fold:
- the average person having no clue what their system is setup as
- laptop users with no or limited control on anything just getting horrible performance due to repeated throttling
- poor sales/rep of a game due to the above noise taking over the conversation
- poor performance and instability associated to UE5

Whether it's shader compilation or some other elements, at some point the engine and tools should put the brakes on how much resources they can pull. No one will complain if shader comp takes another 15seconds as long as it's not causing crashes, hiccups and so on. Even something like restricting the number of threads used for shader comp to 80% of what's available would bring the overall power draw and temps down notably.

I'll dig deeper with overlays to see what's going during actual gameplay, level loads etc but as it stands, the headlines are about intel for now but they'll shift to UE5 issues soon enough.

You can pass the buck onto consumers and IHV's but it'll ultimately put a knock against UE5 if this trend continues.

 

[Scott_Arm]

@RobertR1 Isn't this just instability in the intel platform? Probably hard for games to manage. Trying to integrate power and thermal monitoring into a game loop is probably a non-starter. Maybe they could detect intel cpus and artificially slow shader compilation on boot up, but outside of that it'd be hard to do anything to work around what is essentially a hardware problem.

Intel just updated us on game crashes, and it’s not looking good

The CPU maker confirms that new motherboard BIOS updates will be released soon, but they won't fix the root cause of instability problems.

www.pcgamesn.com

 

[DegustatoR]

You can pass the buck onto consumers and IHV's but it'll ultimately put a knock against UE5 if this trend continues.

If people will still use/run their PCs with unstable overclocks and everyone will say "it's fine" and blame the s/w instead it will. But it is not a problem of the s/w. A PC must be stable no matter what s/w it is running.
And what exactly do you propose Epic to do with this? Downgrade back to UE3 so that such PCs wouldn't crash running modern games?

 

[RobertR1]

@RobertR1 Isn't this just instability in the intel platform? Probably hard for games to manage. Trying to integrate power and thermal monitoring into a game loop is probably a non-starter. Maybe they could detect intel cpus and artificially slow shader compilation on boot up, but outside of that it'd be hard to do anything to work around what is essentially a hardware problem.

Intel just updated us on game crashes, and it’s not looking good

The CPU maker confirms that new motherboard BIOS updates will be released soon, but they won't fix the root cause of instability problems.

www.pcgamesn.com

Correct. It's mainly a bios issue as intel was too loose with enforcing specs and board makers yeet voltages and power draw when you enable xmp/mce. So what you get are crashes when certain loads kick in which if repeated can even lead to degradation. Having a detection for intel cpu's and throttling the number of threads used would avoid the issue more or less.

 

[Karamazov]

funny user mod in fortnite

reminds me of something...

 

[pharma]

UE5 Benchmark application

New GameTech GPU benchmark. Share your results!

Hi all! I have created a new benchmark I hope you like and enjoy! I'm quite proud of the result, even if it's still in its beta phase. GameTech is a benchmark based on Unreal 5 that aims to measure performance and verify stability on today's and tomorrow's modern PCs. Utilizing the most...

www.techpowerup.com

GameTech is a benchmark based on Unreal 5 that aims to measure performance and verify stability on today's and tomorrow's modern PCs. Utilizing the most cutting-edge and innovative gaming technology, it leverages Lumen, Nanite, Virtual Textures, Virtual Shadowmaps, Metahumans... to present an environment that is as realistic, demanding, and optimized as possible, while prioritizing visual quality.

There are several benchmarking modes:

• Without Ray Tracing (Raster): Will use "Lumen Software" if the PC is not compatible with Ray Tracing, or if the user explicitly selects it. Included simply so that older or less powerful cards (within reasonable limits) can still be accommodated.
• Ray Tracing: Will use "Lumen Hardware." The default standard gaming mode.
• Path Tracing: Offline rendering of the highest quality. Will use a fixed resolution of Full HD so that VRAM size is less of a burden and focuses more on measuring performance itself. Additionally, this standardizes the result for all PCs.

 

[trinibwoy]

The First Descendant Performance Benchmark Review - 30 GPUs Tested

The First Descendant is a first-person looter-shooter with support for up to four players working together cooperatively. Powered by Unreal Engine 5, the graphics look great, but hardware requirements are definitely not on the light side. In our performance review, we're taking a closer look at...

www.techpowerup.com

Nanite + RT but it’s not clear where RT is being applied besides reflections. Also not clear if VSMs and Lumen GI are running alongside whatever RT is doing. Maybe RT here just means Lumen?

 

[Andrew Lauritzen]

This Eternal Descent game is making headlines for making systems crash esp on intel cpu's.

I haven't heard about this game specifically but the issues with Intel/Motherboard platform configuration problems has been quite heavily publicized the last few months. There was some early disclosure specifically from the Oodle side here (https://www.radgametools.com/oodleintel.htm), but since then it has been all over the tech press... I'm sort of surprised you haven't seen any of it.

Examples... (there are many more)

There's finger pointing between Intel and Motherboard folks of course, but there were some measures taken to force the motherboard vendors to provide more sensible out of the box settings. You can take your pick on who you want to blame for this situation but it's clear that at least a big chunk of it is Intel pushing these chips too close to the edge, and motherboard vendors often tipping it over.

Note these sorts of issues are not unique to Intel platforms, although this one is pretty bad. But for instance:

Whether it's shader compilation or some other elements, at some point the engine and tools should put the brakes on how much resources they can pull.

Not really, this is ultimately up to the OS. User mode applications are neither able nor responsible for maintaining platform/power stability; put simply if you can run a user mode program and it hangs or bluescreens your whole PC, that is a hardware or kernel issue, full stop.

Even something like restricting the number of threads used for shader comp to 80% of what's available would bring the overall power draw and temps down notably.

If only platforms had sophisticated power and thermal limits on them to address these kinds of situations...

I'll dig deeper with overlays to see what's going during actual gameplay, level loads etc but as it stands, the headlines are about intel for now but they'll shift to UE5 issues soon enough.

You can pass the buck onto consumers and IHV's but it'll ultimately put a knock against UE5 if this trend continues.

This is 100% an Intel problem that they themselves have acknowledged at this point. If the headlines shift to Unreal then you should stop reading those web sites as they don't understand technology. For what it's worth the issues aren't even unique to UE/UE5 - just google around for people seeing the same sorts of problems in Cities Skylines and surprise, surprise, the same platform fixes return to stability.

Correct. It's mainly a bios issue as intel was too loose with enforcing specs and board makers yeet voltages and power draw when you enable xmp/mce. So what you get are crashes when certain loads kick in which if repeated can even lead to degradation. Having a detection for intel cpu's and throttling the number of threads used would avoid the issue more or less.

Not a real mitigation, as applications do not have a full view on what is going on on the system in the first place. Applications' jobs are to present the work they need to do to the OS; the OS is responsible for scheduling and sharing system resources between applications. If that was necessary to make this stable Intel/Microsoft would basically have to push an updated that disabled cores or restricted the turbo limits further. The latter is effectively what they have done and it is the proper "solution", assuming it is hopefully enough.

I normally take softer stances on stuff like this but there really is no gray area in this specific case. As someone who has still spent more of his career at Intel than all the other places combined (for at least a few more years!), this is 100% an Intel problem and no one who knows what they are talking about will tell you otherwise. It's unfortunate that gamers are hitting it in some UE5 titles, but the reality is for many gamers it is probably one of the only workloads on their PCs that actually puts any significant load on their hardware.

 

[Andrew Lauritzen]

The First Descendant Performance Benchmark Review - 30 GPUs Tested

The First Descendant is a first-person looter-shooter with support for up to four players working together cooperatively. Powered by Unreal Engine 5, the graphics look great, but hardware requirements are definitely not on the light side. In our performance review, we're taking a closer look at...

www.techpowerup.com

Nanite + RT but it’s not clear where RT is being applied besides reflections. Also not clear if VSMs and Lumen GI are running alongside whatever RT is doing. Maybe RT here just means Lumen?

From the screenshots my guess would be Nanite + VSM (usually if something is using Nanite, you can probably assume VSM as well for the moment), but it maybe looks a little flat for Lumen. Could just be the way things are set up though... will download it and give it a quick shot.

 

[Frenetic Pony]

The amount of cynical F2P cash in game attempts has been really skyrocketing lately. Hopefully it's a quick check to Epic before people stop playing the game, but I wouldn't put it past the execs at these studios to skip the 5% revenue share