Ipotrick

Specular RTGI! Extended my RTGI to support specular as well as diffuse. Spec and Diff rays are shot from a shared fixed ray pool, the rays are dynamically distributed across the screen based on demand. Perf impact over diffuse-only is around 25%. Am very happy with the result.

Slides for SIGGRAPH 2026 Advances in Real-Time Rendering in Games course's talk on Variable Rate Ray Tracing in Call of Duty: Modern Warfare 4 by Michał Olejnik from Activision are now online - enjoy!! advances.realtimerendering.com/s2026/index....

Pioneer Pretraced rayguiding! * Shoot low res rays * Spatially spread bright ray hits * Use bright rays to guide real traced rays Drastically improved directional GI quality, low cost, around 0.2-0.3ms extra Inspired by Restir, but this has 0 additional temporal lag!

NEW: Surface Detail Guiding! Analyzing surface detail (using albedo and normals, showin in the heatmap) to inform the spatial denoise passes. Flat color -> wide softer blur. Detailed surface -> smaller blur allowing sharp lighting.

New blog post! In "Quantizing tangent frames", we look at various established methods to represent tangent frames in the vertex data, squeeze a few variants into 32 bits per vertex and look at the resulting precision. zeux.io/2026/04/30/q... Share, like and subscribe!

Advances in Real-Time Rendering in Games will be returning SIGGRAPH 2026... The course will be on Tuesday of SIGGRAPH, room and other details TBD. Cool talks lined up - stay tuned for more info.

Also, ghosting, streaking, boiling and all the other common artifacts are largely gone, its very rare that such an artifact still presents itself.

The indirect diffuse denoising now resolves very fast. Evem better since my recent refactor. Here an example of the output in movement before application of albedo (albedo detail can hide potential artifacts). Direct diffuse in the video is a separate system and not denoised, ignore its noise :).

Testing in many different settings is very important for graphics techniques. What works in one setting will fall apart horribly in another. Usually its best to have actual game data to work with. At home i use a lot of dumb test scenes. Very happy to say the GI now works well in all of them 🥳

Mooore denoising tricks 😃!! I tested variance as well as ray-length guided spatial filtering. Variance guided filtering is good at preserving lighting silhouettes, while ray-length guiding adds a lot of contact hardening sharpness! 1. no guiding 2. variance guiding 3. ray-length guiding

More images of the improved denoiser. This showcases how much smarter the prefilter is now. Its able to keep much more lighting energy at better temporal stability. This is a better comparison than in my last post.

I found a few tricks to make the denoiser able to handle a much sparser signal while also increasing temporal stability. With these tricks applied, indirect lighting now looks much better in dark areas. Bright small areas can not illuminate distant pixels much more accurately. Before vs After:

I found a bunch of new tricks for denoising. Using them, i re-architected the whole denoising pipeline. Old: prefilter -> stochastic blur -> upscale -> temporal New: prefilter -> stochastic blur -> temporal -> smooth blur -> upscale. Perf and quality are much better with the new architecture.

I think most raytracing effects and denoisers don't really think about needs of fast games like shooters. For my RTGI denoiser, i put in a lot of care to get an immediately readable and stable image from the first frame after dis-occlusion. its very satisfying.

I would like to showcase the denoisers improvements in movement but videos really just remove all noise so i cant really show the difference :/

I believe this is not done by others because it requires quite a high probe resolution to work properly without loosing too much quality. Luckily, last year i developed a self adapting sparse raytraced probe volume that can reach densities high enough to capture the world in enough detail :).

With my rtgi i am also doing something, that i believe, is a novel technique that i have not seen done before. While probes are often used in rtgi for indirect diffuse on hit shading, i use them to replace all rtgi hit shading. On each hit i project the closest probes radiance into the hits.

Unfortunately the image gets denoised by the image compression quite a lot already. It is much worse noise in reality :)

More denoiser before and after screenshots :)

I have been working on a denoiser for raytraced diffuse global illumination in my hobby engine. I am now quite happy with it. It can create a high quality output with only 0.25 rays per pixel. I am particularly proud of how stable it is in movement and on disocclusions.

Experimenting more with hybrid probe and per pixel traced gi. I now use a radiance cache to shade per pixel ray trace hits. It saves a lot of performance and the quality is very close to proper hit shading. Roughly saving ~30-70% of performance for rtgi (local lights make this verrry worthwhile).

Yoo, timberdoodle is in there. Great projects all around :)

The tech and graphical advancements in Assassin's Creed Shadows are mighty impressive: Micropolygon geometry, fluid wind simulations, ray traced global illumination and so much more. How do they all work and compare to AC games of the past? Find out in my video below! youtu.be/nhFkw5CqMN0

Thread divergence during constant buffer reads can have a big perf impact, this presentation discusses how to detect this on NVidia GPUs using GPU Trace and Shader profiler. Also shows how useful access to ISA is for understanding what the shader does under the hood. www.youtube.com/watch?v=HSsP...

While watching all the trailers from the Sony State of Play I could not help but notice that 90% of the games shown are Unreal Engine games... with each new scene/effect/character shown it is hard not to think "that will probably stutter on PC".

Illume

Thanks to a lot of colleagues' great work, happy to share Vulkan samples for RTX Mega Geometry. They should run on all RTX GPUs using today's new drivers github.com/nvpro-sample... github.com/nvpro-sample... github.com/nvpro-sample... github.com/nvpro-sample...

something I've been thinking about recently: could object-space shading be the key to mitigating artifacts from temporal techniques? accumulating data over time in "shade space" rather than camera frame that flails around. www.oxidegames.com/wp-content/u...

Graphics Programming weekly - Issue 375 - January 19th, 2025 www.jendrikillner.com/post/graphic...

First experiments, using DDGI probes for specular. Made all of bistro super metallic to show the effect. I think this will work really great for rough indirect specular. It would be great if DDGI probes could replace dedicated reflection probes to some extent.