three.js - Three.jsは立方体の4つ​​の角の座標を取得しますか？

Question

立方体の角の4つの座標を取得するにはどうすればよいですか？

Answer 1

CubeGeometry（幅、高さ、奥行き）を使用していて、立方体をどこかに配置した場合、8つの角は次のようになります。

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

Answer 2

完全な実装は次のとおりです。

// 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)

};