/** * @author mikael emtinger / http://gomo.se/ * @author alteredq / http://alteredqualia.com/ */ /* ///Sprite對象,點精靈對象,對應粒子對象,具體的實現是通過BufferGeometry創建1個總是面對相機的平面. /// 用法:var map = THREE.ImageUtils.loadTexture("sprite.png"); //加載image對象 /// var material = new THREE.SpriteMaterial({map:map,color: 0xffffff,fog: true}); //創建材質對象,這里有專門適用于Sprite對象的材質對象SpriteMaterial. /// var sprite = new THREE.Sprite( material); //創建精靈對象. /// scene.add(line); //將精靈添加到場景中. */ ///<summary>Sprite</summary> ///<param name ="material" type="THREE.SpriteMaterial">可選參數,SpriteMaterial對象(點精靈對象專用的材質對象)</param> ///<returns type="Sprite">返回Sprite對象</returns> THREE.Sprite = ( function () { var vertices = new Float32Array( [ - 0.5, - 0.5, 0, 0.5, - 0.5, 0, 0.5, 0.5, 0 ] ); var geometry = new THREE.BufferGeometry(); //使用buffergeometry對象 geometry.addAttribute( 'position', new THREE.BufferAttribute( vertices, 3 ) ); //為geometry對象添加position屬性.這里可以看考BufferGeometry對象的源碼注釋. return function ( material ) { THREE.Object3D.call( this ); //調用Object3D對象的call方法,將本來屬于Object3D的方法交給當前對象Sprite來使用. this.geometry = geometry; this.material = ( material !== undefined ) ? material : new THREE.SpriteMaterial(); }; } )(); /************************************************* ****下面是Sprite對象的方法屬性定義,繼承自Object3D **************************************************/ THREE.Sprite.prototype = Object.create( THREE.Object3D.prototype ); /* ///raycast方法用來取得當前對象與射線（參數raycaster）的交點.raycaster.intersectObject會調用這個方法。主要是用來進行碰撞檢測, /// 在選擇場景中的對象時常常會用到,判斷當前鼠標是不是與對象重適用來選擇對象. /// NOTE：raycast方法中參數intersects參數用來存儲交點的集合，格式以下 /// intersects.push( { /// /// distance: distance, /// point: this.position, /// face: null, /// object: this /// /// } ); /// *////<summary>raycast</summary> ///<param name ="raycaster" type="THREE.Raycaster">射線對象</param> ///<param name ="intersects" type="ObjectArray">交點的屬性集合</param> ///<returns type="ObjectArray">交點的屬性集合</returns> THREE.Sprite.prototype.raycast = ( function () { var matrixPosition = new THREE.Vector3(); return function ( raycaster, intersects ) { matrixPosition.setFromMatrixPosition( this.matrixWorld ); var distance = raycaster.ray.distanceToPoint( matrixPosition ); if ( distance > this.scale.x ) { return; } intersects.push( { distance: distance, point: this.position, face: null, object: this } ); }; }() ); /*updateMatrix方法 ///updateMatrix方法更新場景中當前精靈的平移、旋轉和縮放屬性. */ ///<summary>updateMatrix</summary> ///<returns type="Skeleton">返回新的Sprite精靈對象.</returns> THREE.Sprite.prototype.updateMatrix = function () { this.matrix.compose( this.position, this.quaternion, this.scale ); //compose方法利用變換矩陣的平移、旋轉和縮放設置 this.matrixWorldNeedsUpdate = true; //Sprite對象matrixWorldNeedsUpdate屬性,設置為true. }; /*clone方法 ///clone方法克隆1個Sprite精靈對象. */ ///<summary>clone</summary> ///<param name ="object" type="Sprite">接收克隆的Sprite對象</param> ///<returns type="Sprite">返回克隆的Sprite精靈對象.</returns> THREE.Sprite.prototype.clone = function ( object ) { if ( object === undefined ) object = new THREE.Sprite( this.material ); THREE.Object3D.prototype.clone.call( this, object ); return object; //返回克隆的Sprite精靈對象 }; // Backwards compatibility 向后兼容,粒子被更名為精靈. THREE.Particle = THREE.Sprite;