• Light/Dark
  • Ever wanted an RSS feed of all your favorite gaming news sites? Go check out our new Gaming Headlines feed! Read more about it here.
  • We have made minor adjustments to how the search bar works on ResetEra. You can read about the changes here.

Digital Foundry || Ghostrunner Demo Analysis: Ray Tracing on Unreal Engine 4 Tested In-Depth

ILikeFeet

ILikeFeet

DF Deet Master
Banned
Oct 25, 2017
61,987


A time-limited demo on Steam, Ghostrunner is a highly playable speed-running assassination game running under Unreal Engine 4. It's also using the middleware's new ray tracing features. Alex Battaglia and John Linneman gives their thoughts on the game - and with a bit of console command line magic, we give UE4's early ray tracing implementation a full feature test and thorough performance workout.
Click to expand...
Click to shrink...

and the article
www.eurogamer.net

The Ghostrunner demo is beautiful - and ray tracing adds to the spectacle

Ray traced cyberpunk ninjas - four words that sum up Ghostrunner, a new Unreal Engine 4-powered speed running assassina…
www.eurogamer.net www.eurogamer.net

might do a summary of the video, but everything's in the article already and has pretty pictures
  • RAY TRACED CYBERPUNK NINJAS
  • enemies are obstacles rather than "enemies", succeeds where Mirror's Edge fails
  • RT has huge fps cost, reduces framerate by 64%
  • DX12 is experimental
  • RT AO, RT reflections, RT shadows
  • UE4 Unlocker is an injector that allows access to UE4 console, needed to turn on/off RT features individually
  • shadows has a highly variable cost, the example wall cost 39% of performance, another example cost 63%
  • baked lightmaps hurt RT shadows and AO implementation
  • the game doesn't have a lot of dynamic lighting, so RT shadows and AO doesn't really make sense for this
  • RT reflections make more sense because CYBERPUNK
  • costs can vary from 30% to 70%
  • reflections are full resolution, equals your render resolution
  • 4K render resolution = 4K reflections = tanked frame rate
  • 50% cause temporal instability for some reason, possibly due to low temporal accumulation
  • this game really wants more samples
  • increasing roughness cutoff in UE Unlocker cuts performance heavily
  • you can turn on GI, but it costs 74% of performance, and there's a lot of baked light maps so it's not really recommended
  • one example scene with balls to the walls RT settings at 4K went from 88fps to 7fps
  • looks great tho
  • 1440p with temporal upsampling and RT Reflections (standard roughness cutoff) gets 90+ fps until you get to a reflection or the fan for whatever reason (2080Ti)
  • 2060 is below 60fps with RT on, also vram limitations
  • with just reflections and 1080p, near locked 60fps
  • resolution scaler doesn't use the temporal upsampler, hs to be turned on in the UE unlocker
  • no DLSS in the demo
my thoughts on the game: RT effects really works when you make your game with RT effects in mind. this game doesn't so RT AO and Shadows don't need to be here
 
Last edited:

Deleted member 11276

Account closed at user request
Banned
Oct 27, 2017
3,223
Ooof, that performance impact. Not worth it at all imo. Even at 50% reflections resolution it's just too heavy.

But oh well, it is an experimental branch. I'm sure it will get a lot more optimized in the future.
 
Raide

Raide

Banned
Oct 31, 2017
16,596
Really cool video. Still early days with RT and there are so many added ways to get that performance up to more sensible levels. As the video said, added DLSS would be massive and I hope someone does it to see how it alters the performance.
 
KKRT

KKRT

Member
Oct 27, 2017
1,544
Awesome that Alex made a video about this game, because its amazing and it deserve more recognition :)
 
asd202

asd202

Enlightened
Member
Oct 27, 2017
9,694
RT is the main reason why I expect most next gen games to be 30FPS.
 
Altrich

Altrich

Member
Apr 5, 2018
741
yeah, doesnt really like it worth it for now.

I also just realized i prefer performance more than I do graphical fidelity, I played Deadly Premonition Origins the other day handheld mode on the switch and the horrible graphics didn't bother me one bit
 
OP
OP
ILikeFeet

ILikeFeet

DF Deet Master
Banned
Oct 25, 2017
61,987
summary done

RT really makes sense when you craft your assets for RT. if you have tons of static objects and static lighting, AO/Shadows/GI doesn't make much sense. IMO, this is why a lot of games don't seem to look much better, because it's just slapping effects on top when the assets aren't made for them.
 
Fisty

Fisty

Member
Oct 25, 2017
20,374
Given how ubiquitous UE4 is, I hope this tempers expectations for RT on next-gen consoles. Lots of disappointment incoming for folks who think RT will be everywhere on consoles
 

Deleted member 21709

User requested account closure
Banned
Oct 28, 2017
23,310
Ray tracing for this game looks like the ideal example for 'diminishing returns'. I will definitely try the demo though - will it remove itself from your Steam library come May 12?
 
Shogmaster

Shogmaster

Banned
Dec 12, 2017
2,598
Mr.Deadshot said:
RTX just isn't worth it at the moment. The performance impact is severe.
Click to expand...
Click to shrink...
RT overhead is nuthin'. Wait until gaming adapts 8K multi-angle holographic display with 45X rendering overhead in next decade...
youtu.be

I could hardly believe my eyes! - Looking Glass Holographic Monitor

New users can get $20 off the Drop Koss GMR-54X-ISO Gaming headset at https://dro.ps/tq-gmr-2Save 10% and Free Worldwide Shipping at Ridge Wallets by using o...
youtu.be youtu.be
 
Mr.Deadshot

Mr.Deadshot

Member
Oct 27, 2017
20,285
OP
OP
ILikeFeet

ILikeFeet

DF Deet Master
Banned
Oct 25, 2017
61,987
inguef said:
Ray tracing for this game looks like the ideal example for 'diminishing returns'.
Click to expand...
Click to shrink...
I don't think so, at least not yet. we haven't seen what a game designed to only run with RT looks like yet. everything so far has to run on non-RT enabled hardware so stuff like baked shadows/ao, fully static or stepped time of day, and whatnot are still gonna be prevalent and reduces the impact of ray tracing
 
KKRT

KKRT

Member
Oct 27, 2017
1,544
The performance of current RT is not really telling us anything.
We are in infant years of real time RT algorithms, give it time.
 
Shogmaster

Shogmaster

Banned
Dec 12, 2017
2,598
Mr.Deadshot said:
This isn't half the immersion VR gives you. And VR isn't anti-social when played with other people. It's the contrary.
Click to expand...
Click to shrink...
You can't argue that putting that thing on your head isn't a big barrier to VR adoption. It's just too unwieldy still. And how often do you have two people or more in one room using VR at the same time? It's one person doing it and others watching him/her doing it. It's not a true shared experience.

BTW I'm not saying this is future of gaming displays. That was bit of a lark commenting on rendering overhreads. This holo display is more for collab workspace type deal.
 
Fredo

Fredo

Member
Oct 30, 2017
1,038
Ray tracing will be a sprinkle for next-gen consoles. I would gladly pay for mid-gen upgrades to get more sprinkles.
 
JahIthBer

JahIthBer

Member
Jan 27, 2018
10,401
Probs not the best showcase of RTX, the performance hit is too much for a small difference here. Mirrors Edge is similar to this game somewhat & used Physx to a great effect, it was very noticeable & had a small performance impact, im not sure why more devs didn't use Physx more but as a whole seem to love RTX.
 
Stacey

Stacey

Banned
Feb 8, 2020
4,610
The performance hit on Unreal Engine 4 is substantial even with DLSS 2.0 enabled. (balanced setting)

This includes Mechwarrior 5.

RTX OFF
desktopscreenshot2020xkk2q.png


RTX ON
desktopscreenshot20202zktl.png


94fps to 44fps
 
Galava

Galava

▲ Legend ▲
Member
Oct 27, 2017
5,090
DLSS 2.0 is a must if you want RT, it's just not worth it performance-wise otherwise.

And RT options need to be split and optimized. Seems like RT wasn't optimized at all in this game (having RT SSAO option when SSAO is already baked makes no sense)
 
Vitamin_B_Complex

Vitamin_B_Complex

Member
Jan 21, 2019
2,903
This is probably the worst showcase of RT I have ever seen. The improvements are almost invisible during gameplay and the performance cost is insane. Their tradition solution are pretty good and make RT seem unnecessary. The game was clearly designed around those options and RT came later when it made little sense to have them actually. But I appreciate that it's there as a means to future proof it.
 
Last edited:
Thatguy

Thatguy

Banned
Oct 27, 2017
6,207
Seattle WA
The performance hit for Ray Tracing isn't worth it. It barely looks any better and the FPS hit is nearly 50%. I'm getting out my giant "Industry Buzz Word" stamp...
 
KKRT

KKRT

Member
Oct 27, 2017
1,544
SolidSnakeUS said:
Ray tracing is a serious hog. The fact that enabling RTX for Minecraft will knock your frames down to only a third of what it was before is really telling of how power hungry ray tracing is.
Click to expand...
Click to shrink...
The funny thing about Minecraft is that actually RT is not that heavy, the heaviest part by substantial amount is the denoiser which runs on Shader Cores, not RT cores.
 
jett

jett

Community Resettler
Member
Oct 25, 2017
44,687
This demo is really fun.

But I'm gonna be really pissed if console devs are going to start trading performance for these exceedingly meager RT results.
 

Deleted member 11276

Account closed at user request
Banned
Oct 27, 2017
3,223
KKRT said:
The funny thing about Minecraft is that actually RT is not that heavy, the heaviest part by substantial amount is the denoiser which runs on Shader Cores, not RT cores.
Click to expand...
Click to shrink...
That is true, apparently Nvidia is working on a Tensor core accelerated denoiser right now. Probably since Turings invention, those kind of neural networks take a long time to train. A very long time. Best example is DLSS.

But once it's ready, it should also significantly improve Raytracing performance and also improve quality.
 
Uhtred

Uhtred

Alt Account
Banned
May 4, 2020
1,340
I think full RTX features make most sense when it's the only option or the dominant option for doing shadowing and lighting in a game.

In those cases you gain:

- Dynamic environments vs all static ones.
- Reduction in development costs due to less required work on baked lighting/level design.
- Obviously more accurate, and realistic lighting/shadowing.

Which is why most games won't be doing this next gen. Even with the consoles supporting it, I just don't think the ray tracing capability of those machines will support it. Only PC will be able to, and probably not really well until mid gen.

Instead we'll see traditionally shadowed and lit games next gen, with lots of baked lighting (at least the games that will make us go WOW), with maybe one or two ray traced features like reflections.

This game looks pretty cool too, hadn't heard of it.
 
Pottuvoi

Pottuvoi

Member
Oct 28, 2017
3,068
Simplifying shaders seen in reflections should help for performance.
Complex surfaces and loosing coherency of textures and shading is incredibly expensive.

I would expect virtual textures which flatten surfacelayers to become quite common in games which use RT. (perhaps even baking light just for reflections.)
 
MrKlaw

MrKlaw

Member
Oct 25, 2017
33,278
JahIthBer said:
Probs not the best showcase of RTX, the performance hit is too much for a small difference here. Mirrors Edge is similar to this game somewhat & used Physx to a great effect, it was very noticeable & had a small performance impact, im not sure why more devs didn't use Physx more but as a whole seem to love RTX.
Click to expand...
Click to shrink...

right - but if the performance impact remains the same, what dev will remove the baked lighting etc (to benefit from RT) because the performance isn't worth it and what do you do for users without RT hardware?

Sounds like accommodating users with low RT hardware or no RT hardware means you need to maintain static/non RT lighting in your engines so supporting both could be a lot more effort than just turning a few effects on/off
 
collige

collige

Member
Oct 31, 2017
12,772
The design of this doesn't seem like a particularly good showcase of RT especially given the baked lighting.
 
Orioto

Orioto

Member
Oct 26, 2017
4,716
Paris
I'm often worried about RT when i see some screen comparison and the commentators are all like "my god just look at that difference it's day and nigh" but actually, i'm pretttttttty sure if you show some of those comparisons to people not knowing, half of them would say the non rt version is more realistic.

Cause RT light is kind of unpredictable. Some things will look better, but for some reason (look at that full RT effect against no RT comparison in the vid) some things will look super flat. Some rasterized light will give a nice little shadow somewhere, when the actual RT lighting will make that part just flat.

I mean the cost being what it is, it's worrying when in most cases, people defending it (and i'd love to be one of them) base their demonstrations on 'obvious" qualities that really aren't that obvious to most people. For exemple, RT images, due to indirect lighting, will often look brighter with less shadows, compared to rasterized light that go for that cinematic contrasted shadows. I can tell you people will find the contrasted black shadows more "realistic" most of the time, really.
 
RingRang

RingRang

Alt account banned
Banned
Oct 2, 2019
2,442
Fisty said:
Given how ubiquitous UE4 is, I hope this tempers expectations for RT on next-gen consoles. Lots of disappointment incoming for folks who think RT will be everywhere on consoles
Click to expand...
Click to shrink...
I've said it from the moment I heard ray tracing would be on the next gen consoles. I fear so many devs will turn it on just to have a bullet point to sell their game on rather than actually give a shit about performance.

If the choice comes down to 60fps or ray tracing I don't think many gamers would choose ray tracing. Even seeing ray tracing demo'd in this video I don't honestly think it adds that much to many of these scenes. The faked lighting can look pretty damn good in most cases. It's just not worth it IMO.
 
DarthBuzzard

DarthBuzzard

Banned
Jul 17, 2018
5,122
Shogmaster said:
Because VR is anti-social. This can be shared by people in one room. Also I HATE putting shit on my head.
Click to expand...
Click to shrink...
No. VR is the most social technology we have. At most it's isolating, and that's different to anti-social. It's also something that can be fixed with high quality mixed reality allowing the real world to bleed in on a per-object basis.

Looking Glass and light-field displays for that matter have a genuine place in the future, but they have much more limited use and will feel unimpressive in gaming next to VR and AR.
 
orava

orava

Alt Account
Banned
Jun 10, 2019
1,316
Hope that the nvidia 30xx series rumors about 4 x RT performance are true.
 

cgcg

Banned
Oct 27, 2017
430
results are very underwhelming to be honest. Then you factor in the huuuuge performance hit yea not worth it at all
 
You must log in or register to reply here.