three.js 制作魔方

【2】JMicro微服务部署架构及实例

因为之前的几节讲了一些数学方法,例如Vector3、Matrix4、Euler还有Quaternion的知识。所以这篇郭先生就来说说用three.js怎么制作一个魔方。在线案例请点击博客原文

制作魔方主要运用坐标变换的知识,制作魔方的方法有很多,建议你先在大脑中构思,然后试着做一做,下面我将一种比较简单的方法。

  1. 制作出魔方各个方块的位置坐标(27个)的数组,然后制作出魔方各个面的材质(6个)
  2. 根据坐标和材质制作魔方的方块,并添加到一个组group
  3. 制作一个标志被选面的几何体(我是用球体),然后隐藏
  4. 使用THREE.Raycaster,给模型绑定事件,并记录选定的一些数据,将标志显示并放到合适的位置
  5. 点击模拟方向键盘,根据之前记录的数据,转动魔方(重点)

以上是主要的步骤,但是对于新同学,需要注意的仍然很多,下面上主要代码,按照方法说

Java面试必问:ThreadLocal终极篇 淦!

1. 定义的变量

posArr = [
    [100,100,100],[100,100,0],[100,100,-100],[100,0,100],[100,0,0],[100,0,-100],[100,-100,100],[100,-100,0],[100,-100,-100],
    [0,100,100],[0,100,0],[0,100,-100],[0,0,100],[0,0,0],[0,0,-100],[0,-100,100],[0,-100,0],[0,-100,-100],
    [-100,100,100],[-100,100,0],[-100,100,-100],[-100,0,100],[-100,0,0],[-100,0,-100],[-100,-100,100],[-100,-100,0],[-100,-100,-100]
],//方块位置坐标
materials,//材质数组
mouse = new THREE.Vector2(),//通过鼠标点击的位置计算出raycaster所需要的点的位置,以屏幕中心为原点,值的范围为-1到1.
raycaster,//射线对象
group,//存放魔方方块的数组
groupTemp,//魔方转动时临时数组
object3d,//魔方被选择面的标志物对象
currentPos,//魔方被点击小块的位置
currentNor,//魔方被点击小块面的法向量
currentUp,//魔方被点击时,相机up的向量

2. 定义材质数组

initMaterial() {
    var map_red = new THREE.TextureLoader().load('/static/images/color/m_red.jpg', () => this.loadover --);
    var map_orange = new THREE.TextureLoader().load('/static/images/color/m_orange.jpg', () => this.loadover --);
    var map_yellow = new THREE.TextureLoader().load('/static/images/color/m_yellow.jpg', () => this.loadover --);
    var map_blue = new THREE.TextureLoader().load('/static/images/color/m_blue.jpg', () => this.loadover --);
    var map_green = new THREE.TextureLoader().load('/static/images/color/m_green.jpg', () => this.loadover --);
    var map_white = new THREE.TextureLoader().load('/static/images/color/m_white.jpg', () => this.loadover --);
    var map_sprite = new THREE.TextureLoader().load('/static/images/base/direction.png', () => this.loadover --);

    let mater_red = new THREE.MeshBasicMaterial({map: map_red, side: THREE.DoubleSide});
    let mater_orange = new THREE.MeshBasicMaterial({map: map_orange, side: THREE.DoubleSide});
    let mater_yellow = new THREE.MeshBasicMaterial({map: map_yellow, side: THREE.DoubleSide});
    let mater_white = new THREE.MeshBasicMaterial({map: map_white, side: THREE.DoubleSide});
    let mater_blue = new THREE.MeshBasicMaterial({map: map_blue, side: THREE.DoubleSide});
    let mater_green = new THREE.MeshBasicMaterial({map: map_green, side: THREE.DoubleSide});

    materials = [mater_red, mater_orange, mater_yellow,mater_white, mater_blue, mater_green];
}

3. 绘制小方块并绘制标志物(先隐藏)

initsquare() {
    var sphereGeom = new THREE.SphereGeometry(10, 30, 20);
    var sphereMate = new THREE.MeshPhongMaterial({color: 0x333333});
    object3d = new THREE.Mesh(sphereGeom, sphereMate);
    object3d.name = 'object3d';
    object3d.visible = false;
    scene.add(object3d);

    group = new THREE.Group();
    group.name = 'group';

    var geometry = new THREE.BoxGeometry(100, 100, 100);
    var mesh = new THREE.Mesh(geometry, materials);
    posArr.forEach((d,i) => {
        let meshCopy = mesh.clone();
        meshCopy.position.set(d[0], d[1], d[2])
        meshCopy.name = 'box-' + i;
        group.add(meshCopy);
    })

    scene.add(group);

    this.render();
    document.getElementById("loading").style.display = "none";
}

4. 监听模型的点击事件

initEventListener() {
    raycaster = new THREE.Raycaster();
    document.addEventListener('mousemove', function (event) {
        event.preventDefault();
        mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
        mouse.y = - (event.clientY / window.innerHeight) * 2 + 1;
    }, false)
    document.addEventListener('mousedown', () => {
        if (scene.children && scene.getObjectByName('group')) {
            raycaster.setFromCamera(mouse, camera);
            let intersects = raycaster.intersectObjects(scene.getObjectByName('group').children);
            if (intersects[0] && intersects[0].object.name != 'object3d') {
                let index = intersects[0].faceIndex;
                let point = intersects[0].point;
                currentUp = this.computedUp(camera);
                currentNor = this.computedNor(point)
                currentPos = intersects[0].object.position;
                let pos = this.computedPos(point);
                object3d.position.copy(pos);
                object3d.visible = true;
            }
        }
    })
}

5. 监听方向软键盘的点击,根据点击键的不同,生成旋转轴

handleRotate(num) {
    if(!rotateFlag || !currentPos) return ;
    rotateFlag = false;
    groupTemp = new THREE.Group();
    groupTemp.name = 'group-temp';
    let axis;
    let tempMeshArr = [];
    switch (num) {
        case 1:
            axis = currentNor.clone().cross(currentUp);
            break;
        case 2:
            axis = currentNor.clone().cross(currentUp).negate();
            break;
        case 3:
            axis = currentUp.clone().negate();
            break;
        case 4:
            axis = currentUp;
            break;
    }
    let plane = new THREE.Plane().setFromNormalAndCoplanarPoint(axis, currentPos);
    scene.getObjectByName('group').children.forEach(d => Math.abs(plane.distanceToPoint(d.position)) < 1 && tempMeshArr.push(d))
    tempMeshArr.forEach(d => {
        group.remove(d);
        groupTemp.add(d);
    })
    // object3d.visible = false;
    scene.remove(scene.getObjectByName('group-temp'));
    scene.add(groupTemp);
    this.handleTween(axis);
}

6. 加一点tween的补间动画,效果更好哦

handleTween(axis) {
    let start = {angle: 0, axis};
    let end = {angle: Math.PI/2, axis};
    tween = new TWEEN.Tween(start).to(end, 500);
    tween.easing(TWEEN.Easing.Linear.None);
    tween.onUpdate(function () {
        let quaternion = new THREE.Quaternion().setFromAxisAngle(axis, this._object.angle);
        groupTemp.rotation.setFromQuaternion(quaternion);
    });
    tween.onComplete(() => {
        let matrix = this.standerMatrix(groupTemp.matrix);
        groupTemp.children.forEach(d => {
            let mesh = d.clone();
            mesh.applyMatrix4(matrix)
            mesh.position.copy(this.standarPos(mesh.position))
            group.add(mesh);
        })
        scene.remove(groupTemp)
        rotateFlag = true;
    })
    tween.start();
}

郭先生制作魔方的主要思路就是先做出27个方块添加到组A,6个面分别添加不同颜色的贴图(自己p的哦),然后使用raycaster选择点击的面,并确定当时的up方向和法向量方向以备后用,点击上下左右并结合u方向和法向量方向计算出旋转矩阵,根据已有条件计算出是那一排方块改变,并将这9个块添加到组B中,从组A中删除这9个,根据旋转矩阵旋转组B,并且在旋转完之后将组B中的方块添加到组A中,旋转完毕(这里比较难的就是根据上下左右判断旋转轴向量)。

以上就是一种制作魔方的方法,综合了很多矩阵向量四元数欧拉角和平面的知识,希望对新来的同游有些帮助

 

转载请注明地址:郭先生的博客

three.js 制作魔方
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