Masters - WIP - 22

Masters - WIP - 22, originally uploaded by James D Thompson.

Here ive been setting up an n-spine which is a way i can get the spine to twist correctly and without collapsing.

When you make a spine with the spline ik it works well if the character bends forward of sideways but when they twist on the spot the spline cant solve the twist so it stays still which would look odd. There is a twist attribute in the spline ik but its inefficient as it only twists from the top but if we ever wanted to twist from the hips it wouldn't work.

To solve this the spline ik joints are controlling another joint that's in there place with a point constraint, then those joins are aim constrained to a locator that's in front of them. That locator is then grouped and the pivot moved to the spine joint.

The graph above shows how the rotate y of the 3 controls is fed into the rotate y of the locators groups. and if the locators rotate the joints aiming at them will rotate aswell.

With all this in place now if the chest control is twisted the spine will evenly twist from top to bottom giving a nice and also accurate shape.