code: function inverse(out, a) {
    out[0] = 1.0 / a[0]
    out[1] = 1.0 / a[1]
    out[2] = 1.0 / a[2]
    return out
  }
docs: Returns the inverse of the components of a vec3
  
  @param {vec3} out the receiving vector
  @param {vec3} a vector to invert
  @returns {vec3} out