@BangTao hi again you have asked similar questions two or three times and jumped into Mesh Facet Data thread with a PG combining a little of what you were doing with some of what I showed you and some very new methods without a full understanding- result confusion. Please take a deep breath and think through what you want. You are tending to ask technical questions about your code without telling us what you want to achieve.. You could explain what you want to do overall and the particular