So, I was helping out this guy at 3Dcommune with parenting. He was creating one of these doors, and wanted to be able to move all the doors at once. He was able to create his model and make it the way he wanted it, so he's good to go. In the process though, I made one of my own, and it's been driving me crazy. I don't have any use for it, the curiosity is bugging me. I need to know for sure. I've just decided that it's impossible, and I guess I'm looking for either confirmation, or the proper solution. So, here is this "iris door." I want to be able to create this door so that no gaps appear between the parts as it opens and shuts, and so that the parts don't overlap. (I can get it to do one, but not both) I also want to make it posable, so I'm really limited to rotating the parts, and not actually moving them. Well, I suppose I could move them by parenting to another object and rotating that, but that's another story. So, I guess what I'm asking is this: I have this model, and I don't know where the pivot point is to make the parts move tangentally to one another. I don't even know if such a point exists. I tried the logical ones, and then tried all sorts of points for trial and error. Then, I researched cameras, and there is a lot of overlap involved with them, it's really a different concept. Does anyone know how to make this work? Or can anyone assure me that it's just impossible, and I can rest my brain. It's really a frustrating thing, and what's worse is that I fear that the answer lies in all the Math I'd once learned but have long since forgotten. HELP!