Here's what I've got so far for an arm:
shoulder --> elbow --> wrist
shoulder_IK --> elbow_IK --> wrist_IK
shoulder_FK --> elbow_FK --> wrist_FK
arm_ctrl with Use IK attribute and Stretch Off/On attribute
armDist: Distance tool with locators parented to shoulder and arm_ctrl
Nodes: (--> denotes connection)
armDist.distance --> armDistMultiplyDivide.input1X with .input2X set to 12 (12 is the non-stretched length of the arm)
armDistMultiplyDivide.outputX --> armDistClamp.inputR (minR is 1, maxR is 3)
armDistClamp.outputR --> shoulder_IK.scaleX
armDistClamp.outputR --> elbow_IK.scaleX
This works, believe me.
So I have a blend node setup that control the rotation and scaleX of the shoulder and elbow and can swap between the FK joints and the IK joints. What I would like is to have an off/on setup that would allow me to turn off the stretch. I've tried a condition node but didn't get to far with it. Any body got an idea?