Here's a figure I built which has 3 doors. I've already done the ERC for a simple slide movement going left-right / right-left. No problem there. It works fine. Today I decided to see if I could make the 3 doors 'fold' open like a concertina using ERC. So the second ERC movement involves simultaneous Yrot and Xtrans for doors L and C, and only Yrot for door R (because it doesn't need to move anywhere). The problem is that the movement is only correct at the full value of 1.00. In between, doors L and C are moving and rotating, but door R is only rotating, which makes the whole thing wrong. Or maybe my deltas are totally wrong. The master valueParm channel has min max values of 0 and 1. Here are the 3 slave (doors) Yrot, Xtrans and delta values Yrot : -89.5 / deltaAddDelta -89.500000 Xtrans : -0.623 / deltaAddDelta -0.623000 Yrot : 89.5 / deltaAddDelta 89.500000 Xtrans : -0.639 / deltaAddDelta -0.639000 Yrot : -89.5 / deltaAddDelta -89.500000 Any suggestions as to how I can make this movement work for all 3 doors? mac

Assuming that the origins of the doors are on the left as viewed from the front. Parent door L to door C and door C to door R. Slave the rotateY channels to a master channel with the following values for deltaAddDelta: R = -1 C = 2 L = -2 The values could also be: R = -100.000 C = 200.000 L = -200.000 It's the ratio thats important. Don't use any translateX when trying to concertina the doors.

hi les, There's a problem with parenting the doors to one another. This figure has about 20 body parts and if I re-parent the doors, it would involve a major hassle. Also, each door has a divider and slats parented to it. What I may do is try this with a copy of the figure and see how it goes. Thanks for the help mate! I was beginning to wonder if anyone came in here any more. mac

Unless you can "parent" as les suggests, the math simply doesn't work: the dials are linear. the values needed at the two ends are fixed by your start and end positions and angles (0, 90 degrees). Consider half-way. That's 45 degrees, and 1/2 of positional movement. Does Cos[ 45 degrees ] == 1/2? No.

Sorry, dropped into math-land, without summarizing in plain English: Therefore, the edges of "R" and "C" will not coincide throughout the movement, and you will get the "overlapping" effect you showed.