# Revision history [back]

### Child link of a joint not following parent's movement.

Hey, I'm modelling a robot that mimics a human head, which means I have some joints that rotate in the same axis. To make an analogy with the human head, I have a joint that allows the neck to rotate and two joints to allow the eyes to rotate (all of these joints rotate only in the Z axis).

The problem I have is that when I rotate the neck, the eyes mantain their absolute angle, and not the angle relative to its parent link. Also, whenever I rotate one eye, the neck starts rotating in the opposite direction.

The relevant parts of the model are in this pastebin (I couldn't get the formatting right, sorry)

http://pastebin.com/b2eRC5BY

Is there any way I can correct this behaviour without having to do so with a plugin?

### Child link of a joint not following parent's movement.

Hey, I'm modelling a robot that mimics a human head, which means I have some joints that rotate in the same axis. To make an analogy with the human head, I have a joint that allows the neck to rotate and two joints to allow the eyes to rotate (all of these joints rotate only in the Z axis).

The problem I have is that when I rotate the neck, the eyes mantain their absolute angle, and not the angle relative to its parent link. Also, whenever I rotate one eye, the neck starts rotating in the opposite direction.

direction. The relevant parts of the model are in this pastebin pastebin (I couldn't get the formatting right, sorry)sorry).

http://pastebin.com/b2eRC5BY

Is there any way I can correct this behaviour without having to do so with a plugin?