three.js 制作太阳系统
Posted 郭先生的博客
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最近学了three.js，想拿来练练手，喜欢宇宙，于是亲手撸代码来完成这个，为了更真实，于是查了一些相关资料。
1. 距离太阳由近及远分别是【水星，金星，地球，火星，木星，土星，天王星，海王星】
2. 他们分别到太阳的距离为5791, 10820, 14960, 22794, 77833, 142940, 287099, 450400（单位万千米）
3. 他们的半径分别为2440, 6052, 6371, 3397, 71492, 60268, 25559, 24766（千米）
4. 他们的公转周期分别为88, 225, 365, 687, 4329, 10767, 30769, 60152（天）
5. 他们的自转周期分别为58，243，1， 1， 0.41, 0.42， 0.64, 0.65，
好了除了八大行星都已经调查好了，接下来八大行星都将按照真实比例绘制，（由于周期相差过大，遂正比于1/2次方)
1.绘制八大行星
绘制行星很容易，直接看代码
shuixing = renderMesh("shuixing", 0);
jinxing = renderMesh("jinxing", 1);
diqiu = renderMesh("diqiu", 2);
huoxing = renderMesh("huoxing", 3);
muxing = renderMesh("muxing", 4);
tuxing = renderMesh("tuxing", 5);
tianwangxing = renderMesh("tianwangxing", 6);
haiwangxing = renderMesh("haiwangxing", 7);
scene.add(shuixing);
scene.add(jinxing);
scene.add(diqiu);
scene.add(huoxing);
scene.add(muxing);
scene.add(tuxing);
scene.add(tianwangxing);
scene.add(haiwangxing);
function renderMesh(name, num) {
let texture = new THREE.TextureLoader().load("http://www.bettersmile.cn:90/three_code/assets/textures/planets/"+name+".jpg");
let geometry = new THREE.SphereGeometry(radiuses[num] * RADIUS, 50, 50);
let material = new THREE.MeshBasicMaterial({map: texture});
let mesh = new THREE.Mesh(geometry, material);
mesh.position.x = distances[num] * DISTANCE + SUNRADIUS * RADIUS;
return mesh;
}
在绘制的同时，我们还固定了他们的位置哦，
2.绘制小行星带
八大行星都绘制好了，怎么能少了小行星带呢？由于小行星带都是不规则的石头，这里我们使用上一节的ConvexGeometry()渲染。
let asteroidTexture = new THREE.TextureLoader().load("http://www.bettersmile.cn:90/three_code/assets/textures/planets/asteroid.jpg"); asteriods = renderAsteriod(asteroidTexture); scene.add(asteriods); function renderAsteriod(texture) { let asteroid = new THREE.Geometry(); let asteroidMate = new THREE.MeshBasicMaterial(); for(var i=0; i<20000; i++) { let points = []; let rad = Math.pow(Math.random(), 3) * ASTERIODRADIUS; for(var j=0; j<30; j++) { points.push(new THREE.Vector3(Math.random() * RADIUS * rad, Math.random() * RADIUS * rad, Math.random() * RADIUS * rad)) } var asteroidGeom = new THREE.ConvexGeometry(points); var asterMesh = new THREE.Mesh(asteroidGeom, asteroidMate); //2.17-3.64 * 14960 = 32450 - 54450 let dis = (Math.random() * 22000 + 32450) * DISTANCE + SUNRADIUS * RADIUS; let angle = Math.random() * Math.PI * 2; asterMesh.position.x = dis * Math.sin(angle); asterMesh.position.y = Math.random() * ASTERIODRADIUS * RADIUS * 4 - ASTERIODRADIUS * RADIUS * 2; asterMesh.position.z = dis * Math.cos(angle); asterMesh.updateMatrix(); asteroid.merge(asterMesh.geometry, asterMesh.matrix); } let mesh = new THREE.Mesh(asteroid, new THREE.MeshLambertMaterial({map: texture, emissive: 0x484137})); return mesh; }
我们渲染了20000个小行星，这里小行星带距离太阳2.17~3.64个天文单位，一天文单位为14960万千米。
3.加下来我们绘制太阳，月球，土星环
绘制太阳，月球和土星环（土星环P了好久），相对容易，太阳设置在原点，月球围绕地球，土星环围绕土星，
let taiyangTexture = new THREE.TextureLoader().load("http://www.bettersmile.cn:90/three_code/assets/textures/planets/sun.jpg"); let yueqiuTexture = new THREE.TextureLoader().load("http://www.bettersmile.cn:90/three_code/assets/textures/planets/yueqiu.jpg"); let tuxinghuanTexture = new THREE.TextureLoader().load("http://www.bettersmile.cn:90/three_code/assets/textures/planets/tuxinghuan.png"); let taiyangGeom = new THREE.SphereGeometry(SUNRADIUS * RADIUS, 50, 50); let taiyangMate = new THREE.MeshBasicMaterial({map: taiyangTexture}); let yueqiuGeom = new THREE.SphereGeometry(MOONRADIUS * RADIUS, 50, 50); let yueqiuMate = new THREE.MeshBasicMaterial({map: yueqiuTexture}); tuxinghuan = renderTuxinghuan(tuxinghuanTexture); tuxinghuan.position.copy(tuxing.position); scene.add(tuxinghuan); taiyang = new THREE.Mesh(taiyangGeom, taiyangMate); yueqiu = new THREE.Mesh(yueqiuGeom, yueqiuMate); yueqiu.position.set((distances[2] * DISTANCE + SUNRADIUS * RADIUS) + MOONDISTANCE * DISTANCE, 0, 0); scene.add(taiyang); scene.add(yueqiu); function renderTuxinghuan(texture) { let geom = new THREE.RingGeometry(16, 24, 50, 10, 0, Math.PI * 2); let mate = new THREE.MeshLambertMaterial({emissive: 0xaa8766, transparent:false, opacity: 0.8, map: texture, side: THREE.DoubleSide}); let ring = new THREE.Mesh(geom, mate); ring.rotation.x = - Math.PI / 2; ring.rotation.y = - Math.PI / 12; return ring; } function initCanvas() { let canvas = document.createElement(\'canvas\'); canvas.width = 16; canvas.height = 16; let context = canvas.getContext(\'2d\'); let gradient = context.createRadialGradient(canvas.width / 2, canvas.height / 2, 0, canvas.width / 2, canvas.height / 2, canvas.width / 2); gradient.addColorStop(0, \'rgba(244,164,33,1)\'); gradient.addColorStop(0.2, \'rgba(244,164,33,1)\'); gradient.addColorStop(0.4, \'rgba(244,164,33,.6)\'); gradient.addColorStop(1, \'rgba(0,0,0,0)\'); context.fillStyle = gradient; context.fillRect(0, 0, canvas.width, canvas.height); return canvas; } function initSunshine() { let centerBallLite = new THREE.Sprite(new THREE.SpriteMaterial({ map: new THREE.CanvasTexture(initCanvas()), blending: THREE.AdditiveBlending })); centerBallLite.scale.x = centerBallLite.scale.y = centerBallLite.scale.z = 250000 * RADIUS; scene.add(centerBallLite); }
这里我们的土星环使用了RingGeometry（）几何体，太阳的光晕使用CanvasTexture（）
4.让星球动起来
让所有星星动起来，使用自转和公转，这里需要一点三角函数的功底，
function allStarsSelfRotate() { taiyang.rotation.y = 1 / Math.sqrt(25) * step1 * SELECYCLE; yueqiu.rotation.y = 1 / Math.sqrt(30) * step1 * SELECYCLE; shuixing.rotation.y = 1 / Math.sqrt(58.65) * step1 * SELECYCLE; jinxing.rotation.y = - 1 / Math.sqrt(243) * step1 * SELECYCLE; diqiu.rotation.y = step1 * SELECYCLE; huoxing.rotation.y = step1 * SELECYCLE; muxing.rotation.y = 1 / Math.sqrt(0.41) * step1 * SELECYCLE; tuxing.rotation.y = 1 / Math.sqrt(0.42) * step1 * SELECYCLE; tianwangxing.rotation.z = 1 / Math.sqrt(0.64) * step1 * SELECYCLE; haiwangxing.rotation.y = 1 / Math.sqrt(0.65) * step1 * SELECYCLE; asteriods.rotation.y = 1 / 50 * step1 * PUBLICCYCLE; step1 ++; } function allStarsPublicRotate() { shuixing.position.set(rotating(0).x,0,rotating(0).z); jinxing.position.set(rotating(1).x,0,rotating(1).z); diqiu.position.set(rotating(2).x,0,rotating(2).z); huoxing.position.set(rotating(3).x,0,rotating(3).z); muxing.position.set(rotating(4).x,0,rotating(4).z); tuxing.position.set(rotating(5).x,0,rotating(5).z); tianwangxing.position.set(rotating(6).x,0,rotating(6).z); haiwangxing.position.set(rotating(7).x,0,rotating(7).z); tuxinghuan.position.copy(tuxing.position); yueqiu.position.set( (distances[2] * DISTANCE + SUNRADIUS * RADIUS) * Math.cos(step2 / Math.sqrt(durations[2]) * PUBLICCYCLE) + (MOONDISTANCE * DISTANCE) * Math.sin(step2 / Math.sqrt(10) * PUBLICCYCLE), 0, - (distances[2] * DISTANCE + SUNRADIUS * RADIUS) * Math.sin(step2 / Math.sqrt(durations[2]) * PUBLICCYCLE) + (MOONDISTANCE * DISTANCE) * Math.cos(step2 / Math.sqrt(10) * PUBLICCYCLE) ); step2 ++; } function rotating(num) { let x = (distances[num] * DISTANCE + SUNRADIUS * RADIUS) * Math.cos(step2 / Math.sqrt(durations[num]) * PUBLICCYCLE); let z = - (distances[num] * DISTANCE + SUNRADIUS * RADIUS) * Math.sin(step2 / Math.sqrt(durations[num]) * PUBLICCYCLE); return {x, z}; }
全是简单的三角函数，呵呵
5.加上星空
星空我们直接使用PointsMaterial（），我们随机3000个点（点太多会很乱）。
function initSprites() { let geom = new THREE.Geometry(); let mate = new THREE.PointsMaterial({ size: 0.2, vertexColors: true, color: 0xffffff, transparent: true, opacity: 0.6 }) for(var i=0; i<3000; i++) { let x = Math.random() * 10000 - 5000; let y = Math.random() * 10000 - 5000; let z = Math.random() * 10000 - 5000; if(x*x+y*y+z*z > 250000) { var vector = new THREE.Vector3(x,y,z); geom.vertices.push(vector); geom.colors.push(new THREE.Color(0xffffff)); } } cloud = new THREE.Points(geom, mate); scene.add(cloud); }
x*x+y*y+z*z > 250000，为了让他们处在很远的地方，我们过滤掉离中心小于500的星星，所以剩下的应该不多。
6.加上tween动画和飞行相机
动画我们是先给每个星球一个镜头（毕竟球球平等，但是给了地球最好的贴图），然后俯瞰整个太阳系
function initTween() { let pos = {x: 41, y: 17, z: -35, lx: 0, ly: 0, lz: 0}; let tween1 = new TWEEN.Tween(pos).to({x: 40.36, y: 0.29, z: 2.642, lx: 40.54, ly: 0, lz: 0}, 20 * ANIMATIONTIME); tween1.easing(TWEEN.Easing.Linear.None); let tween2 = new TWEEN.Tween(pos).to({x: 67.41, y: 0.43, z: -4, lx: 65.7, ly: 0, lz: 0}, 22 * ANIMATIONTIME); tween2.easing(TWEEN.Easing.Linear.None); let tween3 = new TWEEN.Tween(pos).to({x: 84.6, y: 0.91, z: -3.42, lx: 86.4, ly: 0, lz: 0}, 24 * ANIMATIONTIME); tween3.easing(TWEEN.Easing.Linear.None); let tween4 = new TWEEN.Tween(pos).to({x: 127.66, y: 0.26, z: -1.47, lx: 125.56, ly: 0, lz: 0}, 27 * ANIMATIONTIME); tween4.easing(TWEEN.Easing.Linear.None); let tween5 = new TWEEN.Tween(pos).to({x: 177.78, y: 1.64, z: -61.37, lx: 200.84, ly: 0, lz: 0}, 30 * ANIMATIONTIME); tween5.easing(TWEEN.Easing.Linear.None); let tween6 = new TWEEN.Tween(pos).to({x: 359.81, y: 11.44, z: -26.28, lx: 400.76, ly: 0, lz: 0}, 35 * ANIMATIONTIME); tween6.easing(TWEEN.Easing.Linear.None); let tween7 = new TWEEN.Tween(pos).to({x: 703.65, y: 34.43, z: -73.74, lx: 726.29, ly: 0, lz: 0}, 40 * ANIMATIONTIME); tween7.easing(TWEEN.Easing.Linear.None); let tween8 = new TWEEN.Tween(pos).to({x: 1441.76, y: 2.69, z: -26.5, lx: 1447.09, ly: 0, lz: 0}, 50 * ANIMATIONTIME); tween8.easing(TWEEN.Easing.Linear.None); let tween9 = new TWEEN.Tween(pos).to({x: 2262.5, y: 4.43, z: 17.22, lx: 2263.59, ly: 0, lz: 0}, 65 * ANIMATIONTIME); tween9.easing(TWEEN.Easing.Linear.None); let tween10 = new TWEEN.Tween(pos).to({x: -374, y: 452, z: -3.4, lx: 400.76, ly: 0, lz: 0}, 85 * ANIMATIONTIME); tween10.easing(TWEEN.Easing.Linear.None); tween1.chain(tween2); tween2.chain(tween3); tween3.chain(tween4); tween4.chain(tween5); tween5.chain(tween6); tween6.chain(tween7); tween7.chain(tween8); tween8.chain(tween9); tween9.chain(tween10); var onUpdate = function () { var px = this.x; var py = this.y; var pz = this.z; var lx = this.lx; var ly = this.ly; var lz = this.lz; camera.position.set(px, py, pz); camera.lookAt(new THREE.Vector3(lx, ly, lz)) }; tween1.onUpdate(onUpdate); tween2.onUpdate(onUpdate); tween3.onUpdate(onUpdate); tween4.onUpdate(onUpdate); tween5.onUpdate(onUpdate); tween6.onUpdate(onUpdate); tween7.onUpdate(onUpdate); tween8.onUpdate(onUpdate); tween9.onUpdate(onUpdate); tween10.onUpdate(onUpdate); tween1.delay(70 * ANIMATIONTIME); tween2.delay(30 * ANIMATIONTIME); tween3.delay(30 * ANIMATIONTIME); tween4.delay(30 * ANIMATIONTIME); tween5.delay(30 * ANIMATIONTIME); tween6.delay(30 * ANIMATIONTIME); tween7.delay(30 * ANIMATIONTIME); tween8.delay(30 * ANIMATIONTIME); tween9.delay(30 * ANIMATIONTIME); tween10.delay(30 * ANIMATIONTIME); tween1.start(); tween10.onComplete(function () { off = true; }) }
代码很长不过很好理解...
这样我们就完成了一个简单的太阳系。
想看demo的请移步至 郭志强的博客
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