Barry - WIP - 09

Barry - WIP - 09, originally uploaded by James D Thompson.

This is one of the stretch arms with no mel :D.

I have a measurement tool connected to the clavicle and wrist joints so I know the length of the arm.

So this is how maya reads it :)

1) The condition node asks, is the distance tool less than or equal to the arms default length with no stretch.

2) If true, the arm is either in its normal position or smaller, so we want no stretch as we want to bend wit Ik so the joints scale = 1.

3) If false (i.e. the animator has stretched the arm by moving the wrist too far) then the values for the joints scale comes from the multiply divide node.

4) The multiply/divide node takes the current length of the arm (the distance tool) and divides it by the length of the arm at default. So e.g. if the default length is 2, if there is no stretch the arm length will = 2, so there divided to = 1 and the joints scale is 1. if the arm is stretched to a length of 6, the its 6 / 2 = 3. This way the arm stretches as you want it to, without this the arm would scale + the defaults arm length, which leads to a huge pop when stretching and a massive offset which leaves the arm stretch useless. But with it it works :D

Also, if you reduce the "default arm size" this means you can shrink the arm before it bends with the IK