Well I am doing a small animation and decided that this time I would use IK solvers (sounded too complex when I first started) and I am having a problem with the spine of my character. I am trying to get the spine to twist as the spine would when you look behind you and the only way I have found so far is the "Swivel Angle" spinner but the problem is that it rotates the spine as a single piece and I would like it to rotate gradually from the bottom to the top. I have tried limiting the rotation of the bones but the bones acted unexpectedly and it did not change the effect of the swivel angle spinner. Have googled for a few hours now and have a fairly substantial headache so if you could help it would be much appreciated.

Additional - I am also having trouble getting the IK chain to allow the spine to bend from side to side so if there is a solution to this as well then please let me know.

If there are multiple solutions to these problems, as there usually is, then if possible I would like to know which methods would allow me to control these movements through a dummy object which is already controlling the default bend direction (Forward/Backward).

Thanks in advance,
Ross

Well I have found a solution to the twisting, well, kind of. Basically using overlapping IK chains I can change the amount of twist at different points, this I suppose can do, however, I will continue the rest of the rigging process and hope that someone might be able to tell me how to make a single chain have a gradual swivel, failing this if you could help me in making adjustable links for the swivel targets (so that I can rotate one control object and have them follow at different resistances). I am pretty sure that this may be done with wire parameters but sadly I don't really know anything about wire parameters.

I have still not been able to find how to add a bend direction for the IK chain (too allow the character to lean side to side) so please, if you know the solution speak up.

Thanks (hopefully in advance)
Ross

Ok, well my final solution for my problem is using a spline IK solver instead of a HI solver, spine using only 3 verts for that I can still control the shape from just my control shapes and the using the wire parameters to link the start and end twists to my control objects. Seems that only the spline IK solver has the two twist controls.

Just thought I would post the solution in case anyone else is having this problem.

Thanks LostRoss for posting your solution!!!
BTW I've never used IK for the spine in 3ds max only forward kinematics.

Cheers!
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Andyba, 3d artist
skills: 3d modeling, texturing, rendering, 3d character animation, compositing
3d software experience: 3ds max, Maya, Softimage XSI, Deep Paint 3d, Body Paint 3D, Wings 3D, Z Brush
2d software experience: Adobe Photoshop, Adobe After effects, Macromedia Flash, Freehand