1.Rotate Plane Solver. Ah, the rotate plane solver. This little gem is pretty much the bread and butter of most pose based CG animation. In this tute we set up the hierarchy using C4D's legacy IK system and override its tags with an up vector node.. Basically the ik is used to animate a 2d system that is calculated till it hits the hip pivot. the pivot has an anchor on it that tells c4d when to stop calculating its ik function along a given length of limbs. The up vector node overrrides the anchor and enables a parent system that is calculated in 3d space. Basically it gives you a realistic knee bend and precise control over the orientation of the entire system.