Lionel Lemarié

My Blendercon Lightning talk "OpenUSD: Don't Worry About It!" is now also available in text if you prefer reading: rystorm.com/blog/openusd... And with a fixed video, without Google Slide glitches: www.youtube.com/watch?v=P8Kp... Huge thanks to the Blender folks for allowing me to fix the video!

New random sampling method for three-gpu-pathtracer: blue noise dither sampling! It offsets a common random sequence for ALL screen samples, yielding a cleaner image in just a few samples. Screenshots are single sample scrambled sobol vs blue noise. Small writeup below👇

One of the weirder things I made for Keeper was a faux fractal generator in substance designer. These were used as alphas for sculpting and some VFX. #gameart

Sharing my tiny #voxel editor app that I've been working on for the past year: polycube.app It has nice-looking color sliders, three different brushes and a #raytracing renderer with a built-in denoiser ✨ Looking to keep updating it, still so many things on the to-do list! 📋

Control is out on iOS now, Ray Tracing and all!

INTRODUCTION TO SPHERICAL HARMONICS FOR GRAPHICS PROGRAMMERS finally done. gpfault.net/posts/sph.html

Behind the pretty frames of #PRAGMATA. Breaking down many tricks and hidden gems of the renderer behind CAPCOM's RE Engine. i hope you enjoy & find this few months worth of freetime article useful... mamoniem.com/behind-the-p...

My erosion filter is out! Video, blog post, and shader source. It emulates erosion without simulation, so it's fast, GPU friendly, and trivial to generate in chunks. Explainer video: www.youtube.com/watch?v=r4V2... Companion blog post: blog.runevision.com/2026/03/fast... #ProcGen #vfx #GameDev

The #WebGPU global illumination engine is getting somewhere, now with volumetric light shafts (00:58) and fully destructible environments. Sorry about the mouse cursor, that's how you know it's real, AI would _never_.

Got some time to spend on the pathtracer denoiser. It's getting there, and the next step is to fix those disocclusion artefacts. I will start working more and more on this project, and share more info hopefully soon! #rust #webgpu

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.

New post on how to do real-time diffuse global illumination using surfels and #WebGPU: juretriglav.si/surfel-based... #threejs

This was a fun quick experiment: Using an old photo I took in the forest, I used ml-sharp to generate gaussian splats from it, voxelized it in my toy renderer, relit the scene dramatically. #rendeting #metalrt

Switched from ImGui to SwiftUI

Coloring a fractal is interesting in itself. Finding good colors is tricky. Applying them to the "right parts" is tricky. Here's a comparison of off-white vs a value that's displaced relative to the folding for each iteration (then mapped to a color ramp). #fractals #rendering #metalrt

Ok, so I'm completely stuck trying to debug this. Left is pathtraced reference, right is my realtime renderer. Top row are metals, bottom row are dielectrics, and roughness goes from 0 to 1 left to right.

Render a fractal in 2 easy steps. 1. Render a sphere. 2. Render the rest of the... fractal. #rendering #metalrt

How to render a fractal in two easy steps: 1. Render a fractal. 2. Fold it into a fractal. #rendering #metalrt

New blog post! (yep, at New Year's Eve.) A short detour into a fun one-liner shading model I use for clouds in my game 🥰 lisyarus.github.io/blog/posts/a...

New post! "Realtime Raytracing in Bevy 0.18 (Solari)" jms55.github.io/posts/2025-1...

My "No Graphics API" blog post is live! Please repost :) www.sebastianaaltonen.com/blog/no-grap... I spend 1.5 years doing this. Full rewrite last summer and another partial rewrite last month. As Hemingway said: "First draft of everything is always shit".

Cem Yuksel's update to the teapot model looks great with a glass material! #metalrt #rendering

A modernized Utah Teapot model with interior! You can see/customize/download it, along with historical versions on the official teapot page: graphics.cs.utah.edu/teapot/

After nine years of development, meshoptimizer has reached its first major version, 1.0! This release focuses on improvements in clusterization and simplification as well as stabilization. Here's a release announcement with more details on past, present and future; please RT! meshoptimizer.org/v1

Zorah looks like a nice level-up if you've conquered the classic Swallowing the Elephant challenge! (pharr.org/matt/blog/20...)

Some images showing off my improvements to my photon mapper I have integrated into truetrace The photon mapper is up on the Dev branch on the github

My latest coding adventure is now up on YT -- some experiments with ray-tracing glass and water, and the cool caustics they can cause youtu.be/wA1KVZ1eOuA?...

Experimenting with a face extrusion and retraction brush in my toy #voxel editor. Threw a bit of #raytracing in there while I was at it ✨