CODEWITHSUNDEEP
three.js
Rails beginner
Rails beginner

Reputation: 14504

Three.js get the 4 corner coordinates of a cube?

How do I get the 4 coordinates for the corners of a cube?

Upvotes: 4

Views: 2897

Answers (2)

Peter Ehrlich
Peter Ehrlich

Reputation: 7125

Here's a full implementation:

// 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)

};

Upvotes: 2

gaitat
gaitat

Reputation: 12632

If you are using the CubeGeometry (width, height, depth) and you positioned the cube somewhere, then your eight corners are at 

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

Upvotes: 3

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