February 19, 2026
GPU glam, Safari slam
Show HN: A physically-based GPU ray tracer written in Julia
Julia’s shiny ray tracer sparks Safari rants, AMD cheers, and “Where’s Julia now?” debates
TLDR: Julia now has a plug-in ray tracer that makes scientific scenes look movie-real, and you can try the demos today. Comments erupted over iOS Safari glitches, cheered AMD’s progress, and questioned whether Julia ever beat Python—making this launch both a tech feat and a culture clash.
Julia just dropped a shiny toy: RayMakie + Hikari bring Hollywood-style lighting right inside its graphics toolkit Makie. Translation: photorealistic images (think light bouncing, foggy clouds, shiny metals) on your computer’s graphics chip, without switching tools. It’s not fully released yet, but the RayDemo is live, so the curious can already play. Hikari is a port of PBRT (Physically Based Rendering), the famous open-source reference, with a focus on clouds, materials, and realistic lighting.
But the comments? Pure drama. One user’s iPhone Safari started auto-fullscreening videos—instant rage-scroll. Another crowd cheered that this was vetted first on AMD, not NVIDIA, calling it a sign that AMD’s ROCm software is finally growing up. And then came the nostalgia slap: “Didn’t Julia promise to replace Python?” Some say the hype cooled; others argue Julia quietly took over in research labs and scientific visuals.
Deep nerds poked the bear: can this renderer handle tricky interfaces—like a glass full of water and ice—without hacking the code, a sore spot in PBRT? That sparked a friendly brawl over materials and realism, while someone simply declared it “an impressive tool.” The mood swings from “Safari sabotage” to “Team Red vs Team Green” to “Is Julia back?”—with path-traced clouds providing the literal silver lining.
Key Points
- •RayMakie and Hikari integrate physically based GPU path tracing directly into Julia’s Makie, enabling photorealistic rendering of any Makie scene via a backend swap.
- •The system supports global illumination, spectral rendering, volumetric media, and physically based materials, running on AMD, NVIDIA, and CPU backends via KernelAbstractions.jl.
- •Hikari is a Julia port of pbrt‑v4 implementing a wavefront volumetric path tracer; intersections are handled by Raycore.jl using AMD’s Radeon Rays SDK and HIPRT.
- •The projects are not yet fully released; early access is available through the RayDemo repository, with official releases planned in the coming weeks.
- •Showcases include Breeze.jl rendering Oceananigans.jl LES cloud fields with NanoVDB volumes and a terrain demo using ArcGIS elevation data via Tyler.jl.