Rendered Milum Lights

Selection of showcased lights rendered with our web-based light simulation system

Lighting design software is usually built for professionals: heavy, complex, and not something you'd hand to a customer configuring a lamp online. I built a web-based lighting simulation and configurator that runs physically accurate path tracing right in the browser, so someone shopping for lighting can see a realistic render update as they change fixtures.

The system renders complex lighting setups using real-world photometric data (IES files) for accuracy. The part I'm happiest with is a texture-based approach that precomputes the lighting effects, so the whole thing still runs smoothly on low-spec hardware instead of needing a GPU workstation.

LiSi Path Tracing Steps

(1) Direct light contribution, (2) Indirect light contribution, (3) Blurred indirect light contribution, (4) Final blended texture

It runs on WebGL and GPU-based path tracing, so feedback is immediate: move a light and the render updates in real time. The system is now used in production on a lighting manufacturer's online store.

LiSi Web Interface Screenshot

The LiSi web application provides an intuitive interface for configuring and simulating lighting systems in real-time.

Features

  • Physically Accurate Light Simulation: Uses GPU-based path tracing with real-world photometric data (IES files)
  • Web-Based and Interactive: Runs in a browser with WebGL, no installation required
  • High Performance: Optimized texture-based rendering for smooth performance on low-end hardware
  • Real-Time Configurator: Users can adjust light positions, temperature, and intensity with instant visual feedback
  • Industry Application: Integrated into a commercial lighting manufacturer's online store

Tech Stack

  • Rendering & Simulation: WebGL, GPU-based path tracing, texture-based global illumination
  • Frontend: React, TypeScript, JavaScript, SVG-based UI rendering
  • Optimization Techniques: Shader-based analytical calculations, iterative texture updates for indirect lighting
  • User Interaction: Always-valid configuration approach, smooth animations with React Spring

Publications

  • Fluri, L., Riedi, M., & Cords, H. (2024). Web-based light simulation and interactive configuration for lighting systems. In Proceedings of the 21st International Conference on Applied Computing.