Ever seen one of these, and wondered *why* they work? 🧵 This is a so-called Bitonic sorting network, and the illustrations show the two common ways to implement them. From an implementation point of view the two methods are effectively the same, so which one you pick just comes down to preference.

Our #SIGGRAPHAsia 2025 paper "Sample Space Partitioning and Spatiotemporal Resampling for Specular Manifold Sampling" improves #realtime #caustics rendering. Project Page: graphics.cs.utah.edu/research/pro... @daqilin.bsky.social @tizian.bsky.social

Another SIGGRAPH Asia gem: research.nvidia.com/labs/rtr/pub... "Sample Space Partitioning and Spatiotemporal Resampling for Specular Manifold Sampling" by Hong et al., which combines sample space partitioning with ReSTIR to efficiently handle caustics.

The z-buffer and depth testing (aka z-testing) have been the dominant way of hidden surface elimination for over 50 years, introduced but not implemented in W. Straßer's PhD thesis in 1974, and actually implemented in Ed Catmull's PhD thesis in the same year. 1/4

I finally added double support for positions in my engine and I can now draw objects at enormous distances from each other. This only cost ~15% scene graph update perf on CPU and it's almost free for GPU since everything is drawn relative to camera using float www.youtube.com/live/eYZ6wS9...

Even if I'm not working directly on rendering clouds at the moment, I still somehow take screenshots of them as I work😀

I had previously used triangle meshes to render giant planetary atmospheres but after many unsuccessful attempts to fix all the artifacts, especially when intersecting atmosphere geometry, I decided to add support for spheres to my renderer. It works much better

Finally got around to implementing async scene loading in my engine. DX12 async compute for BLAS + background threads for bvh command list and resource loading. A lot of pain with synchronizing all of this and the ability to delete objects during loading www.youtube.com/watch?v=kkWa...

Because of texture streamer it became necessary to almost always use mip maps, so I had to do basic normal map filtering, otherwise the surfaces become too shiny and flat. Only roughness without anisotropy for now. Images in order: mips disabled/enabled/+filtering. More below...

I'm working on texture streaming right now, and the first thing I tried was hardware tile streaming with sampler feedback. And yes, the state of hardware streaming is very sad. bsky.app/profile/fabr...

Holy shit, I am just catching up with this article, which goes way further down the mipmap filtering rabbit hole than any other resource I've seen, including showing differences in GPU vendor hardware implementations. pema.dev/2025/05/09/m...

Tried DLSS RR in my path tracer and it's pure magic. I think it's quite expensive for games (~7ms for this image on laptop 3080), but for previz in path tracing it's really good, very resposive and high quality. www.youtube.com/watch?v=xtzW...

Just updated Intel OIDN for the first time in a couple of years in my renderer so I can use GPU version, and it works so well with DOF, motion blur, volumetrics and it's pretty fast. There is a little blurriness in some cases but it's totally solvable www.youtube.com/watch?v=YcHG...

New old blog post: I wrote this back in 2020 but didn't bother to finish editing/uploading until yesterday about how I made this forest scene as a technical art exercise. Slowly working my way through finishing/editing/uploading unfinished old blog posts... blog.yiningkarlli.com/2020/12/lupi...

Implemented a very simple timeline and motion blur in my path tracer. Just animating the scene a bit and accumulating frames (works well with rotation). Even 128 camera samples seems to be enough for even fairly fast movement www.youtube.com/watch?v=cwzP...

I'm excited to share our latest paper (work with Matt Pharr and Tomas Akenine-Möller), "Improved Stochastic Texture Filtering Through Sample Reuse" accepted to I3D'2025. arxiv.org/abs/2504.05562 research.nvidia.com/labs/rtr/pub... 1/

Managed to get Nvidia Flow (PhysX) to compile and run, after initially failing the other week. Was curious for a quick peek now that it's been open sourced (github.com/NVIDIA-Omniv...) Flow itself isn't CUDA based, but instead uses compute shaders Some higher level observations in the replies 1/?

Another experiment with beautiful clouds by @samuel_krug. All colors here are just from the planet's atmosphere and lightning, just different angles of the sun. It's slow but interactive and without lightning mesh light it's 2-3 times faster. Something needs to be done about this

I’m excited to announce that due to popular demand, we will release the full animatic of Flow aka Float aka the Crazy Frog Edition. Instead of using storyboards, all the scenes are designed directly in 3D. Everything was made in Blender and rendered in EEVEE.

It can be interactive with upscaler enabled (in the second half of the video I use AMD FSR2) www.youtube.com/watch?v=9yCE...

Intersecting heterogeneous volumes with multiscatter + exponential high analytical + mesh lights is hard. Now it's 30-40 percent faster for such scenes (more bounces more performance gain)

I found a nice approximation to the integral of projected areas of an SGGX: integral sqrt( w^T S w ) dw ~= pi * ( (1-1/sqrt3) * ( sqrt(S00) + sqrt(S11) + sqrt(S22) ) + (1+1/sqrt3) * sqrt( S00 + S11 + S22 ) )

I continue to work on analytical volumetrics and have discovered an interesting side effect when the volume stack size is not sufficient www.youtube.com/watch?v=kF7s...

Added secondary layer to the spherical analytic media with its own params for color and phase function. Here the first layer is with Rayleigh scattering and the second with Henyey Greenstein for fog www.youtube.com/watch?v=WNJ-...

The first Moana was my first credit at Disney Animation, so working on Moana 2 was a cool opportunity to revisit and reflect over how much I've learned and worked on over the past decade. Here's a short blog post with some thoughts from working on Moana 2: blog.yiningkarlli.com/2024/12/moan...

Quick test of the atmosphere rendering at long distances. The camera is in an atmosphere roughly the size of the Earth. The second volumetric sphere on the horizon with the same size, but at a distance to the Moon. I think I need to switch to doubles for positions in my engine

Just playing with a new toy. Really like scattered colors from atmosphere in the scene. www.youtube.com/watch?v=4VdI...

Did quick experiments with analytic spherical volumes from zero-radiance.github.io/post/analyti... It works in my renderer just like any other analytic volume (it's not special atmosphere subsystem). Here I use some random colors and sphere size www.youtube.com/watch?v=8JJE...

Stochastic raymarching with enhanced sphere tracing.

One day I started working on my engine/renderer and I haven't been able to stop yet