public void WriteFlatRigidVertex(FlatRigidVertex v)
 {
     _stream.WriteShort4N(v.Position);
     _stream.WriteShort2N(v.Texcoord);
     _stream.WriteUByte4N(v.Tangent);
 }
 public void WriteFlatRigidVertex(FlatRigidVertex v)
 {
     _stream.WriteFloat3(v.Position.XYZ);
     _stream.WriteFloat2(v.Texcoord);
     _stream.WriteFloat3(v.Normal);
     _stream.WriteFloat3(v.Tangent.XYZ);
     _stream.WriteFloat3(v.Binormal);
 }