Welcome back to the world of Three.js ! Today, we’re going to explore the RectAreaLight — a special type of light that mimics the soft, diffused glow of rectangular light sources, like fluorescent ceiling lights, LED panels, or even the light coming through a window. Imagine you’re in a modern office with sleek, rectangular lights on the ceiling. The light spreads evenly, creating a soft and natural illumination. That’s exactly what a RectAreaLight does in Three.js ! Sample image ### What is a RectAreaLight ? In Three.js, a RectAreaLight is a light source that emits light from a rectangular plane. Unlike a PointLight , which radiates light in all directions, or a DirectionalLight , which shines in one direction, a RectAreaLight spreads light evenly across a defined area. This makes it perfect for simulating real-world light fixtures like ceiling lights, TV screens, or even windows.