Your approach appears to overlook the coupling relationships between fingers. For hands with fewer degrees of freedom, there exist constraints between the joint angles of individual fingers.

[yys-abu]

My hand has only one active degree of freedom per finger, with all others being passive. For instance: middle_joint1 = 2.03 middle_joint0, middle_joint3 = 1.95 * middle_joint2 How should I modify the code to satisfy this linear relationship? Calculating energy requires gradients for all variables, yet those with gradients cannot be altered.