And Pathtracing has been optimized for real time applications. You can change the traditional rasterizing direct lightning model in UE5 to something like nVidia's RTXDI and have a less than 50% performance lost.
Yeah, but being pedantic about terminology, i would say that NVs extensions to PT turn it into another algorithm. Not totally sure about Restir, but iirc it's caching and reusing samples temporally, but in traditional PT there is no caching. That's what it separates from other correct methods and also what makes it so easy to use. It's a big reason of why PT has won the movie industry.
(Basically i refuse to modify the traditional definition of PT from recent realtime tech bending this definition.)
Todays problem is rasterizing and low end systems like a PS5. With only 10 TFLOPs there is nothing you can do.
No. 10tf is plenty. If i want just realtime GI and have no other crazy ambitions 2tf of a PS4 is already enough for 60fps.
That's using my own method, which is quite accurate globally, but lacks high frequency details like hard shadows or sharp reflections.
That's really why i think APU is totally practical, since HF detail is optional. And a 10tf machine can add those details already quite well.
But i do agree that current handhelds like SteamDeck are too weak with GPU, and cause more of a problem than an opportunity. I praise them only in hope they pave the way towards something better.
You can not switch to modern rendering and you must handcoded everything to 10 TFLOPs which restrict portability.
I can. I can use my method as a cache on high end machines, and increase accuracy by running PT on top to handle the first bounce(s). (At least if DXR could support the LOD of my geometry)
This should work very well and perceptual error should approach zero pretty quickly. The extra work is then to spend on the PT branch, not on the base GI system which we need anyway. Ofc. such base system needs to be accurate enough. Crap like Voxel Cone Tracing would not do.
This sounds pretty good, but my problems are: Preprocessing costs during production, and a complex base GI system. Both is surely much harder to maintain than current state of the art. (Excluding Lumen, which seems much worse.)
And i'm also not too optimistic that my stuff would scale down to mobile HW.
So for me its strange when people complain about Raytracing and Pathtracing when image quality is holding back by low end systems
Yes, but if my stuff works out, this problem would be gone. Scaling up is easy, and there is no more holding back from low end.
And i still wonder why UE5 doesnt scale better with a 90 TFLOPs GPU when Nanite rendering happens with compute without the traditional geometry pipeline...
I also wonder why it does so badly on my old 10tf Vega56. No matter if it's a huge Matrix city demo or a small indie game in a single low detail apartment, i get the same 15-20 fps (at some standard 1080p).
So i conclude Nanite is not the problem, but Lumen is. Considering what a patchwork of hacks this is, i do not wonder it can't saturate a 90tf GPU. But that's just a guess.
However, remembering profiler outputs of Portal RTX shown somewhere here, PT is no good way to saturate either. Too many registers for long pipelines, too much divergence everywhere.
You need the big GPU to run it smoothly, but the GPU isn't saturated well. That's really a problem and kinda sad even from the enthusiast perspective.
Ofc. we can judge that it's just worth it. But if you ask me what to do with 90tf and huge VRAM, i would say large and detailed fluid simulations. This would be awesome, and enough brute force work to make the GPU glow.
But that's just a dream. This could not scale down, so it's not really interesting in practice.
We might get it if 90tf is indeed the future standard. I would not complain. I just can't believe it currently.
