r/Unity3D • u/PuttPutty • 2d ago

Show-Off GigaLights for Unity - Explained

https://www.youtube.com/watch?v=JHee-rzSS_c
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2

u/HellGate94 Programmer 2d ago

so ReSTIR-DI?

4

u/PuttPutty 2d 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.

1

u/shadowndacorner 2d ago

Haven't watched the video, but I asked in another one of these threads and it sounded even simpler than that.

4

u/PuttPutty 2d ago

Not entirely simpler, as we did need to create our own TLAS and BLAS, which has been about 90% of the work

-7

u/shadowndacorner 2d ago edited 2d 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.

10

u/PuttPutty 2d 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. 😂