protected override void OnClearAllGeometryData()
 {
     base.OnClearAllGeometryData();
     Normals?.Clear();
     Normals?.TrimExcess();
     TextureCoordinates?.Clear();
     TextureCoordinates?.TrimExcess();
     Tangents?.Clear();
     Tangents?.TrimExcess();
     BiTangents?.Clear();
     BiTangents?.TrimExcess();
 }