center method
      
void
center()
      
     
    
Center the geometry based on the bounding box.
Implementation
void center() {
  computeBoundingBox();
  boundingBox!.getCenter(_bufferGeometryoffset);
  _bufferGeometryoffset.negate();
  translate(_bufferGeometryoffset.x, _bufferGeometryoffset.y,_bufferGeometryoffset.z);
}