Bones not displayed as following IK handle in viewport

[Anonymous]

Hello everyone, first time posting anything but after some rigorous searching and trial-and-error I have yet to solve this problem so I thought it was worth a shot to ask here!

Basically what happens is that my bone hierarchy is not updated properly in the viewport when connected to an IK handle. If I key it and scroll the time slider it works, but not when I am moving in realtime.

When I move the IK handle it displays the bones following it correctly, but when I move a bone which is above the IK handle-bones then the bones just follow statically as they are, it isn't until I update the viewport in one way or another that they snap back and shows the actual position.

I built a test case as you can see, consisting of 4 joints: root, hip, knee and foot. First image is with no movement, in the second picture I have moved the root joint down slightly. As you can see the IK handle hasn't been moved and yet the leg doesn't follow it. In the third picture you can see how it ACTUALLY looks after I have updated the view by moving the IK handle just so slightly.

I have been checking different Maya settings, restarting Maya, restarting computer and updating graphics drivers, to no avail. Any ideas?

[kevin.picott]

I'll post a guess at what is happening, but if you could upload your Maya file then it would be easier to investigate.

The IK handle drives the joint chain to position them into the proper locations that satisfy the end effector's position, at least as best it can. However there is nothing stopping you from manually positioning the joints at some location away from the handle. This is the basic reason that FK/IK solutions can be created.

In other words the behaviour you are seeing looks perfectly reasonable. You move the joint away from the position dictated by the handle, then when something happens to cause the handle to reassert it's position, such as moving the handle or changing the time, then it returns to the original position.

The same thing would happen if you set a keyframe on an object's position, then moved it to another position temporarily. It would maintain that position away from the keyframe value until an update was forced, through a time change or another manipulaton of the object that updated the position.