光源
光的三原色: 紅red、綠green、藍blue。
色彩模式: HSL、HSV。
色相Hue、飽和度Saturation、亮度Lightness、明度 Value。
白色反射所有光(白色的物體利於測試燈光)
Three.js 的光源類
1.環境光
把顏色添加到整個場景和對象的當前顏色上
maya環境光測試
一個藍色的環境光渲染灰色box
THREE代碼重構
環境光的特點:
- 光源顏色影響整個場景
- 沒有特定的光源,不需要指定位置
- 均勻照射,需要配和其它光源弱化陰影
構造函數聲明
THREE.AmbientLight( hex );
function initLight() {
var light=new THREE.AmbientLight(0x0000ff);//藍色環境環境光
var light_help=new THREE.SphereGeometry(16,16,16);
light.add(new THREE.Mesh(light_help,new THREE.MeshBasicMaterial({color:0xffffff})));//藍色球體
scene.add(light);
}
function initObject() {
var r=10;
// var geometry = new THREE.SphereBufferGeometry( r,16,16);
var geometry = new THREE.CubeGeometry(300,300,300,);
//白色反射所有光線
var material = new THREE.MeshLambertMaterial( { color:0xFFFFFF} );//白色
var mesh = new THREE.Mesh( geometry,material);
mesh.position = new THREE.Vector3(0,0,0);
scene.add(mesh);
}
2.點光源
點發散光,例如蠟燭、白熾燈
maya點光測試
maya創建點光源預覽
three代碼重構
點光源PolintLight的構造函數
PointLight(color,intensity,distance);
- color顏色,16進制
- intensity強度,默認1.0,100%強度
- distance距離光源的距離,超過這個距離越遠光的強度會減弱
function initLight() {
var light_point = new THREE.PointLight(0x0000FF,1,1000);//點光源,綠色,rgb
light_point.position.set(20,80,200);
var sphere = new THREE.SphereBufferGeometry( 10, 16, 16 );//添加一個球體
light_point.add(new THREE.Mesh(sphere,new THREE.MeshBasicMaterial({color:0x0000ff})));//綠色球體
scene.add(light_point);
}
2.聚光燈
光源的光線從一個錐體射出,在被照射的物體上產生聚光效果。舞臺燈光
有一個頂角α
maya聚光燈測試
three代碼重構
聚光燈的構造函數
THREE.SpotLight(hex,intensity,distance,angle,exponent);
前三個通俗易懂
- angle:聚光燈的角度,以弧度爲單位,這個角度和光源方向形成的角度
- exponent:衰減參數,越大衰減越快
var spotLight = new THREE.SpotLight( 0xffffff, 1 );
spotLight.position.set( 15, 40, 35 );
spotLight.angle = Math.PI / 4;
spotLight.penumbra = 0.05;
spotLight.decay = 2;
spotLight.distance = 200;
spotLight.castShadow = true;
spotLight.shadow.mapSize.width = 1024;
spotLight.shadow.mapSize.height = 1024;
spotLight.shadow.camera.near = 10;
spotLight.shadow.camera.far = 200;
scene.add( spotLight );
lightHelper = new THREE.SpotLightHelper( spotLight );
scene.add( lightHelper );
shadowCameraHelper = new THREE.CameraHelper( spotLight.shadow.camera );
scene.add( shadowCameraHelper );
3.平行光源(方向光)
平行光束,太陽光進入地球變成生活中的平行光。
maya平行光測試
平行光構造函數
THREEE.DirectionalLight=function(hex,instensizty);
three代碼重構
var light_direction=new THREE.DirectionalLight(0x0000FF,1);//方向光藍色
light_direction.position.set(10,20,6);
var ld_help=new THREE.DirectionalLightHelper(light_direction,20,0x0000FF);
scene.add(light_direction);//方向光
scene.add(ld_help);