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Thread: Biggest weakness in Ray-Traced Games

VFX_Veteran

Industry Professional (Verified)
 
Platforms
  1. PC
  2. PlayStation
  3. Nintendo
Hey guys,

I thought about putting this in the Metro thread but this actually extends to all other RT games so I decided to make it's own thread.

There is a very annoying side effect of full on RT games using Global Illumination (although it is also seen in the UE5 demo with Lumen).

Latency.

If you pay attention enough to the objects/camera moving dynamically in a RT game, you will see a blur mimicking motion blur on the object or a delay in the lighting once the camera is still. It is absolutely annoying. I found this in Metro: EE and the Marbles demo. It's also seen in other games that mimic GI like Lumen in the UE5 demo when the ceiling in that cave broke apart and the GI bounces poured in the cavern.

This will more than likely be a thing until graphics cards/consoles get a LOT more powerful to remedy the delay. Right now I believe the RTX3090 is about the fastest in resolving the ray bounces.

FYI folks. RT doesn't come without some caveats.
 
The guys from DF talked about this as well. To be able to get away with infinite bounce GI on current hardware, you have to introduce a certain latency to it.

I think this will be a very common thing, because it is the smartest solution to that issue so far.

That's the price for real time RT. It's extremely expensive. But I'm still surprised that we are already at this point tbh. I thought it would take longer, so I'm very satisfied with the progress. The current gen Nvidia cards have been a huge step in the right direction. I can't wait for their next gen of cards tbh.
 
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Hey guys,

I thought about putting this in the Metro thread but this actually extends to all other RT games so I decided to make it's own thread.

There is a very annoying side effect of full on RT games using Global Illumination (although it is also seen in the UE5 demo with Lumen).

Latency.

If you pay attention enough to the objects/camera moving dynamically in a RT game, you will see a blur mimicking motion blur on the object or a delay in the lighting once the camera is still. It is absolutely annoying. I found this in Metro: EE and the Marbles demo. It's also seen in other games that mimic GI like Lumen in the UE5 demo when the ceiling in that cave broke apart and the GI bounces poured in the cavern.

This will more than likely be a thing until graphics cards/consoles get a LOT more powerful to remedy the delay. Right now I believe the RTX3090 is about the fastest in resolving the ray bounces.

FYI folks. RT doesn't come without some caveats.

I haven't noticed it much in Metro Exodus, but I'm going to keep an eye out for it now that you mention it.

Do you think the RTX 3090 is actually faster in resolving the ray bounces, i.e. this motion blur effect would be less pronounced than on an RTX 3080?
 
The moblur issues is fixed in the latest patch. I thought it was rays being resolved because of the illumination delay. But as it turns out the blur is coming from DLSS and HDR. I still have my gamma set to low.
 
The moblur issues is fixed in the latest patch. I thought it was rays being resolved because of the illumination delay. But as it turns out the blur is coming from DLSS and HDR. I still have my gamma set to low.

So now we can go back to the biggest weakness in raytraced games being....

AMD!

😂
Just kidding. Kinda.
 
Nah that ray resolving is still annoying. It shows in the marble demo with the ambient occlusion. The marble looks almost like it's not planted to the wood until the movement stops. Then you see the rays resolve to make the AO darker. I hate that latency tbh. It proves that even the 3090 isn't fast enough to cast rays per frame. Instead being cast more than a frame.
 
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The guys from DF talked about this as well. To be able to get away with infinite bounce GI on current hardware, you have to introduce a certain latency to it.
I think future larger DNNs could eventually be trained to replicate photoreal lighting within microseconds maybe even without having to path trace any rays at all.