Hacker News: holg

New comment by holg in "Show HN: Browser-based light pollution simulator using real photometric data"

holg — Sun, 03 May 2026 17:12:45 +0000

i agree, sorry this is some edge-tech, so for safari it is a bit tricky, as it reports to have webgpu, but &force=webgl2 will do the trick. I am working on the fix to have webgpu behave properly on Safari

New comment by holg in "Show HN: Browser-based light pollution simulator using real photometric data"

holg — Sat, 02 May 2026 15:57:31 +0000

Yup, so actually my take as well is, the scene itself is imperfect, i took some known and easy to implement one. So some scene, where some high building is illuminated up, would be desirable...

New comment by holg in "Show HN: Browser-based light pollution simulator using real photometric data"

holg — Sat, 02 May 2026 15:48:32 +0000

That's the real good proposal. I must admit, my focus was on the street lights, which in general are already almost good, compared to what you mention Thanks a lot

New comment by holg in "Show HN: Browser-based light pollution simulator using real photometric data"

holg — Sat, 02 May 2026 12:06:16 +0000

https://iesna.eu/?wasm=skyglow_demo&force=webgl2, tested on wsl2 ubuntu, sorry linux machine in the office :D

New comment by holg in "Show HN: Browser-based light pollution simulator using real photometric data"

holg — Sat, 02 May 2026 12:02:10 +0000

Ok, even so the quality degrades a lot, i added the webgl2 version, it shall load as fallback, if webgpu is not enabled, but can as well be enforced, to see the difference:

https://iesna.eu/?wasm=skyglow_demo&force=webgl2

New comment by holg in "Show HN: Browser-based light pollution simulator using real photometric data"

holg — Sat, 02 May 2026 10:55:27 +0000

I should have mentioned: WebGPU is needed, on Safari there is a bug in the Bevy Overlay, so you only see flickering (very annoying!) This is an upstream issue (on to it) So FF and Chrome works fine (if WebGPU is enabled!)

New comment by holg in "Show HN: Browser-based light pollution simulator using real photometric data"

holg — Sat, 02 May 2026 10:53:34 +0000

Thanks for the information, i should have mentioned, webgpu is explicitly used here, and this might be the issue! Bevy's usage of WebGL2 is not that mature, and i use Bindless rendering (from my own contribution)...

Show HN: Browser-based light pollution simulator using real photometric data

holg — Sat, 02 May 2026 09:08:18 +0000

Hi HN — author here. iesna.eu is a browser-based ecosystem for working with photometric data: parsing standard luminaire files (LDT/EULUMDAT, IES LM-63, Oxytech, ATLA-S001), running design calculations against EN 13201 / ANSI/IES RP-8 / CJJ 45 / IES-IDA MLO, and (the part I most want to show off here) rendering real urban scenes in Bevy with the photometric data driving actual streetlight behavior, including sky-glow contribution. The Skyglow Analysis demo loads a real LDT file into a Bevy scene (Khronos Bistro test asset). The luminaire's intensity distribution drives the streetlight rendering directly — no fudging — and the sky-glow grade updates live as you adjust the uplight percentage. Swap to a full-cutoff fixture and the sky goes from F (Severe) back to A (Excellent). You can see the difference on the buildings as well as in the sky. Stack: Rust core (eulumdat-rs and friends, ~20 crates handling photometric formats), Bevy for the 3D rendering, WASM for browser deployment. No backend; everything runs client-side. About a thousand lines of new code on top of the existing photometric library to make the Bevy integration work. Things I'd love feedback on:

The atmospheric scattering model is currently single-scattering Rayleigh+Mie. Is that defensible for the use case, or should I move toward multi-scattering? The Bistro test scene works well visually but isn't a controlled environment. Anyone know of a public urban geometry asset that's more typical of real road-lighting evaluation? The CJJ 45 implementation (China's national road lighting standard) is the only one I've had to reverse-engineer from translated PDFs. If anyone has primary-source experience with it, I'd value a sanity check.

Open-source on GitHub (eulumdat-rs and the related crates). Crates.io: eulumdat

Comments URL: https://news.ycombinator.com/item?id=47984734

Points: 39

# Comments: 13

New comment by holg in "Show HN: Most GPU Upgrades Aren't Worth It, I Built a Calculator to Prove It"

holg — Tue, 17 Mar 2026 09:26:45 +0000

i miss the Apple GPUs, specially bcs for higher VRAM they compute quite well, not even talking about power efficiency. For my use-cases very often the low VRAM is the limiting factor, where the Apple GPUs often shine, the Apple Tax if seeing this way is nowadays quite low :D

Show HN: Pure Rust IFC/BIM Viewer in the Browser via WebAssembly

holg — Mon, 02 Mar 2026 09:56:54 +0000

I built an IFC building model viewer entirely in Rust — Leptos for the UI, Bevy for 3D rendering (WebGPU/WebGL2), parser. It compiles to a single WASM binary (~5.8MB Brotli), no C++ geometry kernel or JS runtime involved.

  The demo loads the BayArena stadium with 324 floodlights carrying real EULUMDAT photometric data embedded in the IFC file.

Click any fixture to see its polar light distribution, beam angles, and color temperature. Press L to toggle photometric lighting mode it spawns actual light sources derived from the fixture data. Source at https://github.com/holg/bimifc

Comments URL: https://news.ycombinator.com/item?id=47215858

Points: 2

# Comments: 0

New comment by holg in "Show HN: Rust compiler in PHP emitting x86-64 executables"

holg — Sun, 01 Mar 2026 11:09:34 +0000

interesting proof of concept, in php, who would have thought :D

New comment by holg in "Show HN: Claude Remote – control Claude Code on your Mac from your phone"

holg — Mon, 16 Feb 2026 10:29:27 +0000

Sounds interesting, will give it a try, thx for sharing the Code as well

New comment by holg in "Thanks for All the Frames: Rust GUI Observations"

holg — Thu, 12 Feb 2026 16:33:25 +0000

the nice article, thanks for sharing... Oh yes winit everywhere even not expected :D

New comment by holg in "Show HN: Moli P2P – An ephemeral, serverless image gallery (Rust and WebRTC)"

holg — Sat, 07 Feb 2026 14:39:20 +0000

Quite the good idea and concept, thanks for sharing

New comment by holg in "Show HN: Zerobrew – Alternative to Homebrew"

holg — Wed, 04 Feb 2026 13:23:11 +0000

Quite the nice idea, i will check it out and i'd be happy to contribute

New comment by holg in "Show HN: I trained a 9M speech model to fix my Mandarin tones"

holg — Mon, 02 Feb 2026 12:15:59 +0000

Great idea and effort, thanks for sharing. It is even way more strict than my native chinese tryarounds :D

New comment by holg in "China's analogue AI chip runs 12x as fast on 1/200 the energy of digital rivals"

holg — Sat, 24 Jan 2026 12:24:08 +0000

This all sounds impressive, but tbh there are no real provable numbers to evaluate...

New comment by holg in "Show HN: Open-source certificate from GitHub activity"

holg — Sun, 18 Jan 2026 20:19:12 +0000

Nice idea, how about even more badges? Might be some challenge for the clean looking Certificate...

New comment by holg in "Show HN: I built a free football prediction platform with live matches and stats"

holg — Sat, 17 Jan 2026 13:38:45 +0000

OK, interesting, i am not into betting, but it seems the solid solution, the ui is fine to me, i only speak a very limited french, but it is enough to understand the pages...

New comment by holg in "Show HN: Commander AI – Mac UI for Claude Code"

holg — Sat, 17 Jan 2026 10:38:51 +0000

First of all, nice idea, thanks for sharing! I ask myself, how you would tackle lost context with your App? And i am very comfortable with my terminals, i find it convenient to have it in different tabs/windows, so where is the benefit?