Hello, all friends. There are two hands in the .mb file. About my first hand, when I right-click the surface and select Display Level, there are only two level: 0 and 1. The level 2 disappear! So I try again with the same manipulation. But this time, there are three level: 0, 1 and 2. Why this difference exist? Of cause, we can increase the level of detail for a selected region to at most 13 levels. But I want to know why I did this with the as if same manipulation, but the result was difference? I think that there must be some difference between the two manipulation. But I can't find it out. Any ideas? Thank you.