Why Does Inverse Kinematics mess up some motion poses?



  • So i noticed so parts of the body are messed up when having inverse kinematics on for some motion poses, but if i turn it off the motion will come out with no flaws. Is this a common thing to turn it on or off for poses or is there a permanent solution to fix it with keeping it on.



  • IK is designed to be used by moving only the Hip and Feet (for legs). Some times if you use BVH files all the joints will have a value assigned and if you turn on and off IK it will appear to have very little effect. But if you are using movements that do not have all the joints assigned values then you are going to have to issue as in your video. Basically the foot target is going to try and move the foot towards the target spot. Easy way to see this is take a default Andy and move the Hip upwards and watch the feet. They will point the toes down and if you move the hip forward then the feet will start to point backwards. The foot target is not always at the foot.

    So the question is why do you want to leave the IK on? You can turn IK On and Off during your animation. However you will need to bake each area where the IK is On so that all the movements will be placed and will not result in foot slide.



  • @richard60 Ah, ok thank you so much for this information.