/** * @author alteredq / http://alteredqualia.com/ */ /* ///PointCloud點(diǎn)云對(duì)象,在場景中方便的改變大量的點(diǎn)精靈對(duì)象大小,位置等屬性. */ ///PointCloud///Geometry對(duì)象點(diǎn)云對(duì)象里的點(diǎn)集合///PointCloudMaterial對(duì)象(點(diǎn)云材質(zhì)對(duì)象)///返回Mesh對(duì)象THREE.PointCloud = function ( geometry, material ) { THREE.Object3D.call( this ); //調(diào)用Object3D對(duì)象的call方法,將本來屬于Object3D的方法交給當(dāng)前對(duì)象PointCloud來使用. this.geometry = geometry !== undefined ? geometry : new THREE.Geometry(); // //將參數(shù)geometry賦值給mesh對(duì)象的geometry屬性 this.material = material !== undefined ? material : new THREE.PointCloudMaterial( { color: Math.random() * 0xffffff } ); //將參數(shù)material賦值給PointCloud對(duì)象的material屬性,如果沒有傳遞material參數(shù),將創(chuàng)建隨機(jī)色彩材質(zhì),賦值給當(dāng)前PointCloud對(duì)象 this.sortParticles = false; //設(shè)置是不是排序粒子?? //TODO:sortParticles屬性沒有弄明白,有時(shí)間回來處理. }; /************************************************* ****下面是PointCloud對(duì)象的方法屬性定義,繼承自O(shè)bject3D **************************************************/ THREE.PointCloud.prototype = Object.create( THREE.Object3D.prototype ); /* ///raycast方法用來取得當(dāng)前對(duì)象與射線（參數(shù)raycaster）的交點(diǎn).raycaster.intersectObject會(huì)調(diào)用這個(gè)方法。主要是用來進(jìn)行碰撞檢測, /// 在選擇場景中的對(duì)象時(shí)常常會(huì)用到,判斷當(dāng)前鼠標(biāo)是不是與對(duì)象重適用來選擇對(duì)象. /// NOTE：raycast方法中參數(shù)intersects參數(shù)用來存儲(chǔ)交點(diǎn)的集合，格式以下 /// intersects.push( { /// /// distance: distance, /// point: intersectionPoint, /// indices: [ a, b, c ], /// face: null, /// faceIndex: null, /// object: this /// /// } ); /// *////raycast///射線對(duì)象///交點(diǎn)的屬性集合///交點(diǎn)的屬性集合THREE.PointCloud.prototype.raycast = ( function () { var inverseMatrix = new THREE.Matrix4(); //聲明1個(gè)4x4矩陣，用來放置逆矩陣 var ray = new THREE.Ray(); //聲明全局射線對(duì)象 return function ( raycaster, intersects ) { var object = this; var geometry = object.geometry; var threshold = raycaster.params.PointCloud.threshold; inverseMatrix.getInverse( this.matrixWorld ); ray.copy( raycaster.ray ).applyMatrix4( inverseMatrix ); if ( geometry.boundingBox !== null ) { if ( ray.isIntersectionBox( geometry.boundingBox ) === false ) { return; } } var localThreshold = threshold / ( ( this.scale.x + this.scale.y + this.scale.z ) / 3 ); var position = new THREE.Vector3(); //檢查射線與點(diǎn)云元素是不是碰撞的具體實(shí)現(xiàn). var testPoint = function ( point, index ) { var rayPointDistance = ray.distanceToPoint( point ); if ( rayPointDistance < localThreshold ) { var intersectPoint = ray.closestPointToPoint( point ); intersectPoint.applyMatrix4( object.matrixWorld ); var distance = raycaster.ray.origin.distanceTo( intersectPoint ); intersects.push( { distance: distance, distanceToRay: rayPointDistance, point: intersectPoint.clone(), index: index, face: null, object: object } ); } }; //如果geometry對(duì)象是BufferGeometry對(duì)象 if ( geometry instanceof THREE.BufferGeometry ) { var attributes = geometry.attributes; var positions = attributes.position.array; //下面對(duì)3種數(shù)據(jù)格式的pointCloud對(duì)象的元素進(jìn)行檢測. if ( attributes.index !== undefined ) { var indices = attributes.index.array; var offsets = geometry.offsets; if ( offsets.length === 0 ) { var offset = { start: 0, count: indices.length, index: 0 }; offsets = [ offset ]; } for ( var oi = 0, ol = offsets.length; oi < ol; ++oi ) { var start = offsets[ oi ].start; var count = offsets[ oi ].count; var index = offsets[ oi ].index; for ( var i = start, il = start + count; i < il; i ++ ) { var a = index + indices[ i ]; position.set( positions[ a * 3 ], positions[ a * 3 + 1 ], positions[ a * 3 + 2 ] ); testPoint( position, a ); } } } else { var pointCount = positions.length / 3; for ( var i = 0; i < pointCount; i ++ ) { position.set( positions[ 3 * i ], positions[ 3 * i + 1 ], positions[ 3 * i + 2 ] ); testPoint( position, i ); } } } else { var vertices = this.geometry.vertices; for ( var i = 0; i < vertices.length; i ++ ) { testPoint( vertices[ i ], i ); } } }; }() ); /*clone方法 ///clone方法克隆1個(gè)PointCloud點(diǎn)云對(duì)象. */ ///clone///接收克隆的Object3D對(duì)象///返回PointCloud對(duì)象.THREE.PointCloud.prototype.clone = function ( object ) { if ( object === undefined ) object = new THREE.PointCloud( this.geometry, this.material ); object.sortParticles = this.sortParticles; THREE.Object3D.prototype.clone.call( this, object ); //繼承Object3D的clone方法 return object; //返回克隆的PointCloud對(duì)象 }; // Backwards compatibility 向后兼容,粒子系統(tǒng)唄點(diǎn)云對(duì)象替換.用法和THREE.PointCloud對(duì)象1樣. THREE.ParticleSystem = function ( geometry, material ) { console.warn( 'THREE.ParticleSystem has been renamed to THREE.PointCloud.' ); return new THREE.PointCloud( geometry, material ); };