Hi, I would greatly appreciate if someone could help me identify the issue I have with IK for newly created figures.

Once I create IK chains and turn IK ON, when I try to move figure's hands and feet a bit further from the body, outlined object for hands and feet appear outside the selected object that I move. When I release the object that I'm moving the outlines disappear. This seems to be the indicator that something is wrong with the figure setup.

When I pose the figure while IK is ON and when I save the project and reopen it, the pose is completely ruined since both feet and arms are now rotated to some "unnatural" position. The pose and the animation is now completely useless since limbs are no longer positioned properly.

Also, when I pose the figure with IK turned ON, and when I turn IK OFF, suddenly hands and feet move to some other position and the pose is ruined again. This is happening with every figure I setup. I have the same issue in both Poser Pro 2014 and Poser Pro 11.

I am not sure if I am explaining the issue well, so I have attached a link to the video that will probably present the issue better. VIDEO LINK

I'm really stuck here so any suggestion is more than welcome.

From my experience, the "outlines" seem to happen if you try and move the hand or foot further than it can move and still be attached to the body, and that's what I'm seeing in the video. If you don't pull the hand (for example) so far from the body that you get the outlines, I'll bet your problems with the pose being screwed up will go away. If a character's arm is, for example, 2 1/2 poser units long and you try and move the hand 4 units from the body, Poser then has to guess at a whole bunch of position and rotation values.

@almostfm That makes sense. However, Andy figure and other figures such as V4, M4, etc, don't have this issue. If you take Andy for example, it doesn't matter how long I stretch its arms and feet while IK is ON, reopening the project with saved poses will stay intact, IK chain "goals" will stay in the saved position. If I try to do the same with my custom figures and save the pose while IK is ON, upon reopening the project "goals" will be rotated in some other position.

I'm guessing this has to do something with the fact that IK re-parents goals to the body, so I am not sure what I'm missing.

Hi all, Any other ideas?

I am really desperate for help regarding this issue. Any ideas?

kojot303 it's a while since I've played with IK. When I was doing so regularly, I adopted a technique of loading two identical figures, one with IK on, and the other with IK off. Make the non-IK figure appear in outline mode. Save poses for individual frames to the library from the IK figure, and then apply them to the non-IK figure. this will give you a direct indication of what the uncalculated rotations of the IK limbs are set to. Adjust the non-IK figure's rotations to make the limbs coincide with the IK figure's limbs again, and then apply the same rotations to the IK figure. Repeat the cycle to confirm that the IK pose preserves the correct joint rotations when applied to the non-IK figure. This will give you a pose file that works whether IK is turned on or not.

I know this is unnecessarily tedious, but it's the only solution I found, since the IK solver does not properly calculate all of the IK joint rotations to allow the pose to remain identical regardless of the IK state. This is understandable from the viewpoint that translations of the endpoint of an IK limb are not constrained sufficiently to prevent the limb being stretched beyond its non-IK limits. IK also pays no regard whatever to joint rotation limits, when translating the endpoint. This is especially frustrating when dealing with human knees and elbows which do not have six degrees of freedom. Forearms and shins do not normally (OK, people with looser joints do have a small range of movement) bend side-side. That movement is achieved by twisting the upper arm or thigh. IK frustratingly ignores that restriction.

[Answer originally posted on SM Poser Forum]

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My ShareCG Stuff

Verbosity: Profusely promulgating Graham's number epics of complete and utter verbiage by the metric monkey barrel.

Those outlines are the IK targets, that is the point where the hand/foot is trying to get too.  Unless the pose that you apply moves the hand/foot then the IK target is somewhere other than where the pose appears to place it.  So when you re-open a scene then the IK system will try to match the figure to the targets. As far as turning On and Off the IK system, when you turn it off then the Key frame spline takes over and the movement will follow that spline. Depending on how close and extreme the keys/movements are it can lead to massive over-shoot.  If you turn the IK back On then IK system takes over again, but there are now keys on joints that did not have them to begin with and that messes with it a bit.  Biggest issue is that IK is a forward only system so make sure to get the movement correct before turning IK Off.  Once you tun IK Off that portion of the animation is complete and you really can't go back and make changes.  

See the following links for more into.

Improve the IK Function | Renderosity

I may have more about IK here, not sure. I had some at Smith Mirco and RDNA, but thy are both gone.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13

The other thing is that you really should not use IK on both feet and hands at the same time.  IK on hands is best used for hands on a steering wheel that moves back and forth.  The movement should be small so that you don't bend the joint into weird angles.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13

IK Test Jump by Richard60 (renderosity.com)

here is a video showing the effects of IK.  I made two small boxes a green and blue they are proxies for IK targets since you can only see them when you pull the foot away from the target.  Andy's feet are constrained to each box right to green and left to blue much like Andy's feet are constrained to the IK targets.  The blue box stays at the start position until about halfway through and then it jumps to the end.  Notice Andy's left leg points to the blue box starting by pointing backwards then pointing forwards.  I have the green box sort of moving with Andy and his leg follows the green box.  I used the Blue and Green boxes to show what those outlines you mentioned are and how they act.  The animation would be built with IK on and without the boxes.  You would take the Hip and move it down some on frame 15.  Go to frame 135 and move the hip and both feet to the landing area translate Z axis.  Zero Hip at Frame 150.  Finally go to frame 75 halfway point and move the hip up so the figure is off the ground.  Ad there you have a long jump.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13