Three.js 获取立方体的 4 个角坐标？答案

【问题标题】：Three.js get the 4 corner coordinates of a cube?Three.js 获取立方体的 4 个角坐标？
【发布时间】：2014-10-12 02:26:08
【问题描述】：

如何获得立方体角的 4 个坐标？

【问题讨论】：

标签： three.js

【解决方案1】：

如果您使用 CubeGeometry（宽度、高度、深度）并将立方体放置在某个位置，那么您的八个角在

position.x + width/2, position.y + height/2, position.z + depth/2
position.x + width/2, position.y + height/2, position.z - depth/2
position.x + width/2, position.y - height/2, position.z + depth/2
position.x + width/2, position.y - height/2, position.z - depth/2
position.x - width/2, position.y + height/2, position.z + depth/2
position.x - width/2, position.y + height/2, position.z - depth/2
position.x - width/2, position.y - height/2, position.z + depth/2
position.x - width/2, position.y - height/2, position.z - depth/2

【讨论】：

我尝试设置 cube2 的位置。 cube 是一个立方体数组： cube2.position.set(cube.last().position.x,60,70);但得到错误 Uncaught TypeError: Object [object Array] has no method 'last'

【解决方案2】：

这是一个完整的实现：

// Returns the positions of all the corners of the box
// Uses CSS ordering conventions: CW from TL.  First front face corners, then back.
THREE.BoxGeometry.prototype.corners = function(position){
  this._corners || (this._corners = [
    new THREE.Vector3,
    new THREE.Vector3,
    new THREE.Vector3,
    new THREE.Vector3,
    new THREE.Vector3,
    new THREE.Vector3,
    new THREE.Vector3,
    new THREE.Vector3
  ]);

  var halfWidth = this.parameters.width / 2, halfHeight = this.parameters.height / 2, halfDepth = this.parameters.depth / 2;

  this._corners[0].set(position.x - halfWidth, position.y + halfHeight, position.z + halfDepth);
  this._corners[1].set(position.x + halfWidth, position.y + halfHeight, position.z + halfDepth);
  this._corners[2].set(position.x + halfWidth, position.y - halfHeight, position.z + halfDepth);
  this._corners[3].set(position.x - halfWidth, position.y - halfHeight, position.z + halfDepth);
  this._corners[4].set(position.x - halfWidth, position.y + halfHeight, position.z - halfDepth);
  this._corners[5].set(position.x + halfWidth, position.y + halfHeight, position.z - halfDepth);
  this._corners[6].set(position.x + halfWidth, position.y - halfHeight, position.z - halfDepth);
  this._corners[7].set(position.x - halfWidth, position.y - halfHeight, position.z - halfDepth);

  return this._corners

}

THREE.Mesh.prototype.corners = function(){

  if (!this.geometry instanceof THREE.BoxGeometry){
    console.warn('Unsupported geometry for #corners()')
    return
  }

  return this.geometry.corners(this.position)

};

【讨论】：

请注意，在定义 BoxGeometry 形状时必须提供宽度、高度和深度。
假设您有一个立方体在 x 和 z 轴上移动，并且立方体在所有轴上旋转，这不会返回 y 角的正确位置。如果不设置y位置，则默认为0，但为角值添加半高。