Krzysztof Narkowicz

Krzysztof Narkowicz

@knarkowicz.bsky.social

Engineering Fellow at Epic Game. I love games, graphics and lighting. https://knarkowicz.wordpress.com

1.5K followers160 following52 posts

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Krzysztof Narkowicz
@knarkowicz.bsky.social

MegaLights slides were just posted online. There's a bunch of details in slide notes if you're curious how our new Stochastic Direct Lighting solution works, why we made it and want to learn a bit about the problem space.

ceruleite.bsky.social@ceruleite.bsky.social

#SIGGRAPH2025 Advances in Real-Time Rendering in Games course slides for "MegaLights: Stochastic Direct Lighting in Unreal Engine 5” talk by @knarkowicz.bsky.social and @tiagocostav.bsky.social from Epic Games are now online advances.realtimerendering.com/s2025/index....

Krzysztof Narkowicz
@knarkowicz.bsky.social

An interesting idea to use surfels not only as a surface cache (PBGI), but also as a geo approx to trace against. The main use case is mobile, where triangle ray tracing isn’t widely supported in HW, and raymarching SDFs isn’t a great fit for bandwidth-limited devices. gdcvault.com/play/1035619...

gdcvault.comThe Evolution of Real-Time Global Illumination in 'Love and Deepspace' (Presented by Arm)Love and Deepspace is a mobile game dedicated to providing players with a near-realistic romantic experience. Providing realistic rendering on mobile devices is our constant goal. Global illumination ...
Krzysztof Narkowicz
@knarkowicz.bsky.social

Interesting paper showing great results for replacing standard low-res rendering + temporal upsampling (DLSS) with high-res GBuffer + adaptive sampling. Makes sense given rising costs of lighting computations vs GBuffer. arxiv.org/abs/2602.08642

arxiv.orgForget Superresolution, Sample Adaptively (when Path Tracing)Real-time path tracing increasingly operates under extremely low sampling budgets, often below one sample per pixel, as rendering complexity, resolution, and frame-rate requirements continue to rise. ...
Krzysztof Narkowicz
@knarkowicz.bsky.social

Another great article from Chips and Cheese. This time about dynamic RDNA4 register allocation. Having full dynamic allocation would be huge for all those complex shaders we write nowadays, but as the article shows it's not easy to get there.

chipsandcheese.bsky.social@chipsandcheese.bsky.social

Hello you fine Internet folks, Today we are continuing our deep-diving into the RDNA4 architecture with looking at the newly added Dynamic Register Allocation and how it compares to Nvidia's `setmaxnreg`. Hope y'all enjoy! open.substack.com/pub/chipsand... old.chipsandcheese.com/2025/04/05/d...

open.substack.comDynamic Register Allocation on AMD's RDNA 4 GPU ArchitectureModern GPUs often make a difficult tradeoff between occupancy (active thread count) and register count available to each thread.

Krzysztof Narkowicz reposted

Arseny Kapoulkine
@zeux.io

New blog post! "Measuring acceleration structures", in which we will compare BVH costs on various GPU architectures and drivers and attempt to understand the details enough on AMD hardware to make sense of the numbers! Reposts appreciated :) zeux.io/2025/03/31/m...

zeux.ioMeasuring acceleration structuresHardware accelerated raytracing, as supported by DirectX 12 and Vulkan, relies on an abstract data structure that stores scene geometry, known as “acceleration structure” and often referred to as “BVH...
Krzysztof Narkowicz
@knarkowicz.bsky.social

Does anyone know whether DoF is done through path tracing or post in offline movie rendering? I've heard that it's mostly done in post due to performance and extra flexibility, but I wonder whether that's still the case, and whether some shots are rendered (challenging DoF) and some in post.

Krzysztof Narkowicz
@knarkowicz.bsky.social

MegaLights release took me a bit by surprise. It was just a small prototype on a backburner, not planned to be showcased in UE 5.5. Now trying to catch up after the demo push, starting from writing the official docs which just went online: dev.epicgames.com/documentatio...

dev.epicgames.comMegaLights in Unreal Engine | Unreal Engine 5.5 Documentation | Epic Developer CommunityA whole new direct lighting path to place many dynamic and shadowed area lights in an Unreal Engine scene.
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Krzysztof Narkowicz
@knarkowicz.bsky.social

It’s early days. Lots of ideas on P4 shelves, algorithms to try and work left. Not ready yet to talk about tech details. Still, officially the cat is out of the bag, so it’s time to buckle up and deliver on the promise. Can't wait to see the first games shipping with this tech.

Krzysztof Narkowicz
@knarkowicz.bsky.social

MegaLights release took me a bit by surprise. It was just a small prototype on a backburner, not planned to be showcased in UE 5.5. Now trying to catch up after the demo push, starting from writing the official docs which just went online: dev.epicgames.com/documentatio...

dev.epicgames.comMegaLights in Unreal Engine | Unreal Engine 5.5 Documentation | Epic Developer CommunityA whole new direct lighting path to place many dynamic and shadowed area lights in an Unreal Engine scene.
Krzysztof Narkowicz
@knarkowicz.bsky.social

Years ago I talked to a bunch of companies at GDC and everyone was bringing up optimizing number of lights, disabling shadows with distance, light overlap... It felt like there was a big opportunity to transform their workflows, so I started prototyping ideas between other work.

Krzysztof Narkowicz
@knarkowicz.bsky.social

Main goal was to make it work across all target HW, including consoles. Otherwise it would just add extra work for artists setting up another lighting scenario, and high-end GPU lighting would be constrained by content choices, which had to be made to ship on the slower hardware.

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