Gemini Executive Synthesis

iesna.eu, a browser-based ecosystem for working with photometric data, including design calculations and a light pollution simulator.

Technical Positioning

A client-side, browser-based tool for lighting design and light pollution analysis, using real photometric data and advanced rendering, offering an alternative to traditional desktop software.

SaaS Insight & Market Implications

This browser-based light pollution simulator and photometric data ecosystem addresses a specialized need in urban planning, lighting design, and environmental impact assessment. Its client-side WASM architecture, leveraging Rust and Bevy, delivers complex 3D rendering and real-time calculations directly in the browser, eliminating backend dependencies and enhancing accessibility. The use of real photometric data and adherence to international lighting standards (EN 13201, ANSI/IES RP-8) ensures accuracy and professional utility. This tool provides a powerful, interactive platform for visualizing and mitigating light pollution, offering a distinct advantage over traditional, potentially less accessible, desktop solutions. Its open-source nature further promotes adoption and community contribution within a niche but critical engineering domain.

Proprietary Technical Taxonomy

Raw Developer Origin & Technical Request

Hacker News May 2, 2026

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

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

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Developer Debate & Comments

conartist6 • May 2, 2026

I love the idea, but it feels very un-serious as an attempt to educate people or reduce light pollution, which makes me very sad as someone who cares about reducing light pollution :'(Why can't I create any light pollution no matter what I do? The stars wink out when the light pollution is 1000x less bright than the stars. It just feels completely disconnected from what I know light pollution feels like.If I may make a technical suggestion, accurately representing the "qualia" of what both the presence and absence of colorful light feels like on a monitor requires compressing the color space a bit. Take a gander at this: https://brandonli.net/spectra/doc/

holg • May 2, 2026

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

holg • May 2, 2026

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!)

jeroenhd • May 2, 2026

All I get is an empty, dark blue page after I hit Launch Demo. Perhaps that does look a bit like a night sky, but I don't think that's what you're going for :)Tested in Firefox/Brave/Chrome on Linux.

Frequently Asked Questions

Market intelligence mapped to iesna.eu, a browser-based ecosystem for working with photometric data, including design calculations and a light pollution simulator..

What problem does iesna.eu, a browser-based ecosystem for working with photometric data, including design calculations and a light pollution simulator. solve?

Based on our AI analysis of the original developer request, its primary technical positioning is: A client-side, browser-based tool for lighting design and light pollution analysis, using real photometric data and advanced rendering, offering an alternative to traditional desktop software.

What is the general sentiment around iesna.eu, a browser-based ecosystem for working with photometric data, including design calculations and a light pollution simulator.?

Yes, we have tracked 11 direct responses and active debates regarding this specific topic originating from Hacker News.

What architecture is tied to iesna.eu, a browser-based ecosystem for working with photometric data, including design calculations and a light pollution simulator.?

Our proprietary extraction maps iesna.eu, a browser-based ecosystem for working with photometric data, including design calculations and a light pollution simulator. to adjacent architectural concepts including browser-based ecosystem, photometric data, parsing standard luminaire files (LDT/EULUMDAT, IES LM-63, Oxytech, ATLA-S001), design calculations.

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Cross-Market Term Frequency

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