code: function ceil(out, a) {
    out[0] = Math.ceil(a[0]);
    out[1] = Math.ceil(a[1]);
    out[2] = Math.ceil(a[2]);
    return out;
  }
docs: Math.ceil the components of a vec3
  
  @param {vec3} out the receiving vector
  @param {vec3} a vector to ceil
  @returns {vec3} out