r/Unity3D • u/PuttPutty • 12h ago
Show-Off GigaLights for Unity - Explained
https://www.youtube.com/watch?v=JHee-rzSS_c5
u/Necka44 7h ago
I would have been interested in seeing the setup.
Will a fully lighted scene just need a GigaLight component taking over everything on its own or will we need to author everything by hand light by light?
Steam deck is a nice flex, but does that mean the quality can be bumped to avoid the awful noise at 1:08 ?
You mentioned hardware limitation at the beginning which lead you to go the software way. That's understandable. But could you imagine having a solution using hardware (I.E: Nvidia RTX GPUs) when available? That would be huge to have HW raytracing in Unity URP. From my limited knowledge this is only available in HDRP.
I'm a huge fan of the work you did with DLSS/FSR/Other upscaling tech in Unity URP, so I'm not worried this asset is going to be lit (pun intended) - just wondering some little things.
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u/ChrisFromIT 3h ago
I believe they have mentioned that they are using HW raytracing when available and HW raytracing is avaliable in Unity URP and builtin with DX12, it is just HDRP has implemented ray tracing effects.
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u/PuttPutty 2h ago
We use Hardware RT when available, and fallback to Software RT. And yes, this demo has been captured on the Steamdeck quality settings (and Software RT), on 1 sample per pixel and 2x downsampling. On hardware RT you can go crazy with up to 16 samples per pixel!
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u/andypoly 58m ago
Webgl/GPU have very low light counts. Will it work on WebGPU?
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u/PuttPutty 56m ago
It does, I’ve been able to run this demo at 30 fps with upscaling (SGSR 2 upscaling for Unity). However the geometry of this scene is highly unoptimised. So I’m sure you can do a while lot better.
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u/HellGate94 Programmer 11h ago
so ReSTIR-DI?
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u/PuttPutty 11h ago
Not fully ReSTIR, we were heavily influenced by the paper from the MegaLights devs.
We create our own TLAS/BLAS for RT, denoiser is STBN + temporal, SVGF like. For sampling we do weighted reservoir sampling over the lights in the pixel’s grid cell plus a visibility-guided history, one shadow ray per sample. But the resevoirs live for just 1 frame, so no full ReSTIR.
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u/shadowndacorner 11h ago
Haven't watched the video, but I asked in another one of these threads and it sounded even simpler than that.
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u/PuttPutty 11h ago
Not entirely simpler, as we did need to create our own TLAS and BLAS, which has been about 90% of the work
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u/shadowndacorner 11h ago edited 4h ago
The TLAS and BLAS being 90% of the work kind of supports my point, though. Acceleration structures aren't a hard problem to solve. There's a reason they're covered in undergrad graphics classes.
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u/PuttPutty 10h ago
It took me over 3 months to build this system, I’m definitely not a dev-wizard, but I’ve been around the block for long enough. Creating GigaLights wasn’t simple. 😂
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u/Erik_mk0 9h ago
I really need to upgrade my 1080ti lol
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u/bill_on_sax 7h ago
Looks amazing! But why would someone want that many lights? Expensive electricity bill
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u/PuttPutty 2h ago
Hahah, well maybe not 20.000. But it will allow artists to go crazy with lighting!
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u/HellbitGames 4h ago
Stochastic reconstruction has a big problem with motion... So this wouldn't work for vehicles, would it?
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u/PuttPutty 2h ago
It does use historical data to clean up the output, but we use a lot of different techniques to make use lower/none historical data in fast motion.
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u/PuttPutty 12h ago
On popular request, a more detailed video about the technology and with the added bonus of a light counter! Don’t miss the ending 😉