by Lea Rosema
As mentioned in the chapter about lights, some light sources are able to cast shadows.
To enable shadows in your Three.js scene, setup the renderer to use shadow maps:
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap; // default THREE.PCFShadowMap
Lights that have a direction are able to cast shadows. To enable shadow casting for a light source, set:
light.castShadow = true;
Additionally, for the meshes that should receive shadows, set:
plane.receiveShadow = true;
For best performance, a common practice is to use only one lights with shadow-casting enabled. An alternative approach is to use fake shadows, as described in the ThreeJS fundamentals article on shadows (see below).
Check out this demo on CodePen