I'm a long-time reader and asking for the first time. Fairly new to blender with no prior schooling in 3D, I would like to rig an armature to a human skeleton. However, my knee joint (consisting of 3 bones, femur, knee and tibia) makes the tibia clip into the femur, when the leg is folded (as in: When the heel touches the butt).

Here is a snapshot of the clipping knee...

I have tried everything and cannot figure out, how to solve this puzzle. But: If there would be a way of making the knee bone rotate 1.5x the amount of the tibia, the problem would be solved.

Here's an illustration of what I mean by rotating the Knee bone more than by the IK:

As far as I know, that is not possible in an IK with parented and (even worse) connected bones, right? So what's the solution? The human leg "travels around an arc", rather than rotate around a pivot-point. How can I incorporate that "travel" in an IK-rig.

Thanks a lot in advance for all your help. Also thank you all for this wonderful ressource of information in the past.

If ever needed, I'll try and provide a slimmed-down .blend file (new to this).

I'm a long-time reader and asking for the first time. Fairly new to blender with no prior schooling in 3D, I would like to rig an armature to a human skeleton. However, my knee joint (consisting of 3 bones, femur, knee and tibia) makes the tibia clip into the femur, when the leg is folded (as in: When the heel touches the butt).

Here is a snapshot of the clipping knee...

I have tried everything and cannot figure out, how to solve this puzzle. But: If there would be a way of making the knee bone rotate 1.5x the amount of the tibia, the problem would be solved.

Here's an illustration of what I mean by rotating the Knee bone more than by the IK:

As far as I know, that is not possible in an IK with parented and (even worse) connected bones, right? So what's the solution? The human leg "travels around an arc", rather than rotate around a pivot-point. How can I incorporate that "travel" in an IK-rig.

Thanks a lot in advance for all your help. Also thank you all for this wonderful ressource of information in the past.

If ever needed, I'll try and provide a slimmed-down .blend file (new to this).

EDIT: Added the .blend file here: