Comparing Lighting in Babylon.js and Unity's WebGL Exporter

Comparing How to Light in Babylon.js and Unity's WebGL Exporter

Creating interactive 3D experiences in a web browser is possible with various tools, but the way light is handled makes a crucial difference. Babylon.js and Unity's WebGL exporter take opposite paths: one builds from scratch for the web and the other transplants a complete ecosystem. This architectural decision defines everything, from how shadows are calculated to the time it takes for the application to load. 🎯

Opposite Architectural Approaches for Lighting

The main divergence lies in the foundation of the graphics engine. Babylon.js was designed as a native web engine. Its lighting system integrates directly with the browser's graphics APIs, such as WebGL and WebGPU, allowing very fine control over the rendering loop. On the other hand, Unity compiles and packages its entire powerful desktop engine to work on the web. This means Unity's complex global lighting system, with all its tools, is transplanted to the browser environment, with the advantages and costs that entails.

• Control vs Convenience: In Babylon.js, you configure lights, materials, and rendering parameters directly in code (JavaScript/TypeScript). In Unity, you use the visual editor and its panels, then export.
• Performance and Size: Babylon.js's native solution is usually lighter and optimizable from the start. The Unity build can be heavier, affecting load time, especially in complex scenes.
• Advanced Effects: Both allow achieving them, but the path differs: Babylon.js uses its post-processing pipeline or custom shaders; Unity leverages its built-in systems like the Progressive Lightmapper.

The choice sometimes comes down to whether you prefer to build the house brick by brick or transplant a fully furnished castle.

Babylon.js: Native Lighting and Detailed Control

When working with Babylon.js, the developer holds the reins of rendering. The engine offers several built-in light types: point, directional, hemispherical, and spot. You can adjust properties like intensity, range, color, and falloff angle programmatically. To simulate global illumination, there is no automatic system like in Unity; techniques such as precomputed (baked) lightmaps or real-time approximate solutions are used. The great advantage is the ability to optimize every aspect for the web, achieving smooth performance and a reduced application size. ⚡

• Code-based configuration for precise control.
• Lightweight and native architecture for WebGL/WebGPU.
• Global Illumination (GI) achieved with specific techniques (lightmaps, probes).
• Ideal for projects where web performance and total control are priorities.

Unity WebGL: Transplanting a Complete Graphics Engine

Unity's WebGL exporter brings the full power of its graphics engine to the browser. This allows using the same lighting tools as in the desktop version, such as mixed lighting mode and high-quality lightmap baking with the Progressive Lightmapper (CPU/GPU). The visual result can be identical to a PC build, with soft shadows, reflections, and high-fidelity ambient occlusion. However, the price to pay is the complexity of the final build. The developer must adjust compression settings, reduce polygon count, and optimize textures to ensure the experience works well across various browsers and hardware. 🏗️

• Visual workflow identical to desktop.
• Advanced and automated Global Illumination system.
• Final builds can have considerable size.
• Requires actively optimizing the scene for the browser.

Deciding Which Tool to Use

The choice between Babylon.js and Unity WebGL for lighting does not