光与阴影
- 设置物体本身（材质）
- 设置投影到的物体（材质）
- 设置光源（非常重要，直接关系效果--细节、光类型）
- 设置renderder渲染模式。
可以利用 three.js 辅助工具helper调试。
javascript
//Create a WebGLRenderer and turn on shadows in the renderer
const renderer = new THREE.WebGLRenderer();
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap; // default THREE.PCFShadowMap
//Create a DirectionalLight and turn on shadows for the light
const light = new THREE.DirectionalLight( 0xffffff, 1 );
light.position.set( 0, 1, 0 ); //default; light shining from top
light.castShadow = true; // default false
scene.add( light );
//Set up shadow properties for the light
light.shadow.mapSize.width = 512; // default
light.shadow.mapSize.height = 512; // default
light.shadow.camera.near = 0.5; // default
light.shadow.camera.far = 500; // default
//Create a sphere that cast shadows (but does not receive them)
const sphereGeometry = new THREE.SphereGeometry( 5, 32, 32 );
const sphereMaterial = new THREE.MeshStandardMaterial( { color: 0xff0000 } );
const sphere = new THREE.Mesh( sphereGeometry, sphereMaterial );
sphere.castShadow = true; //default is false
sphere.receiveShadow = false; //default
scene.add( sphere );
//Create a plane that receives shadows (but does not cast them)
const planeGeometry = new THREE.PlaneGeometry( 20, 20, 32, 32 );
const planeMaterial = new THREE.MeshStandardMaterial( { color: 0x00ff00 } )
const plane = new THREE.Mesh( planeGeometry, planeMaterial );
plane.receiveShadow = true;
scene.add( plane );
//Create a helper for the shadow camera (optional)
const helper = new THREE.CameraHelper( light.shadow.camera );
scene.add( helper );//Create a WebGLRenderer and turn on shadows in the renderer
const renderer = new THREE.WebGLRenderer();
renderer.shadowMap.enabled = true;
renderer.shadowMap.type = THREE.PCFSoftShadowMap; // default THREE.PCFShadowMap
//Create a DirectionalLight and turn on shadows for the light
const light = new THREE.DirectionalLight( 0xffffff, 1 );
light.position.set( 0, 1, 0 ); //default; light shining from top
light.castShadow = true; // default false
scene.add( light );
//Set up shadow properties for the light
light.shadow.mapSize.width = 512; // default
light.shadow.mapSize.height = 512; // default
light.shadow.camera.near = 0.5; // default
light.shadow.camera.far = 500; // default
//Create a sphere that cast shadows (but does not receive them)
const sphereGeometry = new THREE.SphereGeometry( 5, 32, 32 );
const sphereMaterial = new THREE.MeshStandardMaterial( { color: 0xff0000 } );
const sphere = new THREE.Mesh( sphereGeometry, sphereMaterial );
sphere.castShadow = true; //default is false
sphere.receiveShadow = false; //default
scene.add( sphere );
//Create a plane that receives shadows (but does not cast them)
const planeGeometry = new THREE.PlaneGeometry( 20, 20, 32, 32 );
const planeMaterial = new THREE.MeshStandardMaterial( { color: 0x00ff00 } )
const plane = new THREE.Mesh( planeGeometry, planeMaterial );
plane.receiveShadow = true;
scene.add( plane );
//Create a helper for the shadow camera (optional)
const helper = new THREE.CameraHelper( light.shadow.camera );
scene.add( helper );