如何在轴世界 three.js 上旋转对象？

Question

是否可以以世界而不是对象的轴为轴进行旋转？

我需要对一个对象进行一些旋转，但是在第一次旋转之后，我无法像我想要的那样进行其他旋转。

如果无法在世界轴上进行旋转，我的第二个选择是在第一次旋转后重置轴。有这个功能吗？

我不能使用object.eulerOrder，因为当我在一些旋转后设置object.eulerOrder="YZX" 时，它会改变我的对象的方向。

Answer 1

更新：3 - 0.125.2

演示：codesandbox.io

const THREE = require("three");

const scene = new THREE.Scene();
const camera = new THREE.PerspectiveCamera(
  75,
  window.innerWidth / window.innerHeight,
  0.1,
  1000
);
camera.position.z = 5;

const renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);

const geometry = new THREE.BoxGeometry(1, 1, 1, 4, 4, 4);
const material = new THREE.MeshBasicMaterial({
  color: 0x628297,
  wireframe: true
});
const cube = new THREE.Mesh(geometry, material);
scene.add(cube);

// select the Z world axis
const myAxis = new THREE.Vector3(0, 0, 1);
// rotate the mesh 45 on this axis
cube.rotateOnWorldAxis(myAxis, THREE.Math.degToRad(45));

function animate() {
  // rotate our object on its Y axis,
  // but notice the cube has been transformed on world axis, so it will be tilted 45deg.
  cube.rotation.y += 0.008;
  requestAnimationFrame(animate);
  renderer.render(scene, camera);
}

animate();

Answer 2

@Neil 的更新答案（在 r98 上测试）

function rotateAroundWorldAxis(obj, axis, radians) {
   let rotWorldMatrix = new THREE.Matrix4();
   rotWorldMatrix.makeRotationAxis(axis.normalize(), radians);
   rotWorldMatrix.multiply(obj.matrix);
   obj.matrix = rotWorldMatrix;
   obj.setRotationFromMatrix(obj.matrix);
}

Answer 3

@acarlon 您的回答可能刚刚结束了一周的沮丧。我已经稍微完善了你的功能。这是我的变化。我希望这可以节省我花费 20 多个小时试图解决这个问题的时间。

function calcRotationAroundAxis( obj3D, axis, angle ){

    var euler;

    if ( axis === "x" ){
        euler = new THREE.Euler( angle, 0, 0, 'XYZ' );      
    }

    if ( axis === "y" ){
        euler = new THREE.Euler( 0, angle, 0, 'XYZ' );              
    }

    if ( axis === "z" ){
        euler = new THREE.Euler( 0, 0, angle, 'XYZ' );      
    }
    obj3D.position.applyEuler( euler );
}

function calcRotationIn3D( obj3D, angles, order = 'XYZ' ){

   var euler;

   euler = new THREE.Euler( angles.x, angles.y, angles.z, order );

   obj3D.position.applyEuler( euler );

}

这在 r91 中运行良好。 希望对您有所帮助。

Answer 4

在 r59 附近的某个地方，这变得容易多了（围绕 x 旋转）：

bb.GraphicsEngine.prototype.calcRotation = function ( obj, rotationX)
{
    var euler = new THREE.Euler( rotationX, 0, 0, 'XYZ' );
    obj.position.applyEuler(euler);
}

Answer 5

这里有一个小的变化。用 r56 测试。

THREE.Object3D._matrixAux = new THREE.Matrix4(); // global auxiliar variable
// Warnings: 1) axis is assumed to be normalized. 
//  2) matrix must be updated. If not, call object.updateMatrix() first  
//  3) this assumes we are not using quaternions
THREE.Object3D.prototype.rotateAroundWorldAxis = function(axis, radians) { 
    THREE.Object3D._matrixAux.makeRotationAxis(axis, radians);
    this.matrix.multiplyMatrices(THREE.Object3D._matrixAux,this.matrix); // r56
    THREE.Object3D._matrixAux.extractRotation(this.matrix);
    this.rotation.setEulerFromRotationMatrix(THREE.Object3D._matrixAux, this.eulerOrder ); 
    this.position.getPositionFromMatrix( this.matrix );
}
THREE.Object3D.prototype.rotateAroundWorldAxisX = function(radians) { 
    this._vector.set(1,0,0);
    this.rotateAroundWorldAxis(this._vector,radians);
}
THREE.Object3D.prototype.rotateAroundWorldAxisY = function(radians) { 
    this._vector.set(0,1,0);
    this.rotateAroundWorldAxis(this._vector,radians);
}
THREE.Object3D.prototype. rotateAroundWorldAxisZ = function(degrees){ 
    this._vector.set(0,0,1);
    this.rotateAroundWorldAxis(this._vector,degrees);
}

最后三行只是从矩阵中重新同步参数(position,rotation)...我想知道是否有更有效的方法来做到这一点...