Hamedss wrote: ↑Sat Feb 20, 2021 1:27 pm
thank you my friend but what do you mean by" B9's rotation maps to translation of B6
create B9 with starting angle 0
make an action for B9.
at (say) frame 90 rotate B9 to 90 degrees.
still in the action, at frame 0 select B6 (assuming it is in its resting "straight leg" position
at frame 90 (or wherever you decided) move (translate) B6 to its "fully bent knee" position.
if necessary, at "sensible points" in between, you can add more keyframes to adjust B6's position to make a more realistic bend
hope that helps!