Demo here
Decay is the quantity of light attenuation with the distance
Low level -> less light across far object 0 -> No decay so every object is lighted by the same intensity
Distance = 0 -> no decay & all object in the scene is under the same light intensity.
Need to use Decay with Distance > 0, otherwise distance is useless. With Distance > 0 & Decay > 0, we can set the among of intensity of light across object depending on the distance and decay power
Penumbra is the blur light. Decay is linked to the light level on the element depending on the distance.
Download Node.js. Run this followed commands:
# Install dependencies (only the first time)
npm install
# Run the local server at localhost:8080
npm run dev
# Build for production in the dist/ directory
npm run build