Hello Blender Artists,
I have problems bending knee of my charakter, no matter what settings (roll value) I set, these knees always go in the wrong direction. Even a pole-bone has so far brought no results, with which I would have a solution. Something is wrong.
So I hope for help here.
My current working file I have attached here:
[ATTACH]474446[/ATTACH]
Your leg bones are bent so the knee is behind the line from foot to hip - just move them forwards, in EDIT mode, of this theoretical line, yours below (knees bend backwards):
Required Mod (knees bend forwards):
Then it works… You should NEVER have the bones in an IK chain straight - always bend them slightly in the direction you want the “knee” to move in, then they will fold the way you wanted.
Cheers, Clock. 
EDIT:
This is what your model looks like with a Subsurf Mod in place:
2nd EDIT:
You have no “root” bone - this should be between the feet on the floor and major bones like the lower back and all IK targets should be parented to it so you can control the whole character - see the Rigify Rig as a perfect example of what a biped armature should look like.
Hi Clock, this did help me well! – So a litte mistake but so much influence … Thank you very much!
By the way I will add a root-bone later. But I depended on this problem with the direction, and wanted to solve it before I inserted more bones.
Once again: Thank you!
