If you set it to receive and cast shadows, you will run into a quality problem.
Are there any options for this?
.castShadow = true;
.receiveShadow = true;
the problem is the shadows. try to play with these variable. (Most of the times the problem is the Bias)
renderer.shadowMap.type = THREE.PCFShadowMap
directionalLight.shadow.mapSize.set(512 * 2, 512 * 2);
directionalLight.shadow.camera.near=YOUR INT VALUE;
directionalLight.shadow.camera.far=YOUR INT VALUE;
directionalLight.shadow.normalBias = YOUR FLOAT VALUE (Exj: 0.1);
directionalLight.shadow.bias = YOUR FLOAT VALUE (Exj: -0.0001);
