code: function clone(a) {
      var out = new Float32Array(3)
      out[0] = a[0]
      out[1] = a[1]
      out[2] = a[2]
      return out
  }
docs: Creates a new vec3 initialized with values from an existing vector
  
  @param {vec3} a vector to clone
  @returns {vec3} a new 3D vector