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 the methods that would allow me to control these movements through a dummy object which is already controlling the default bend direction (Forward/Backward).
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 alot Bruce, I haven’t tried following the tutorial quite yet but have had a read through it and it looks like that should work (Still would have liked to have been able to use the single IK chain, if only for simplicity).
Any chance you might know how to allow the chain(s) to effect both the X and Y rotation of the bones in the spine?
Ok, another problem. Following the tutorial and have linked the bottom most dummy object (the swivel target for lowest IK chain) to the main spine controller, and for some reason the dummy object will move as I intended it to but for some reason the IK’s Swivel is not effected when the dummy object is moved as a result of moving the spine controller, however the swivel is effected when the dummy object is moved manually.
Probably a simple solution but I don’t know what it is.
It’s always a challenge to give advice without seeing your actual setup, but there may be an error somewhere in your rigging that subsequent tweaking can’t fix. I think perhaps your best bet, Ross, is to stop tweaking what you currently have and go through the entire rigging tutorial (Character Animation without Biped) using another, very simple model.
For character rigging I use the Reaction Manager quite a bit, also described in the User’s Ref and the Tutorials. But I strongly suggest that you get the hang of straight IK wiring before you attempt Reaction Manager.
Well, I don’t really have time for doing tutorials as I need to finish my complete animation in 2 weeks (college assignment that I left too long, and I can’t ask the tutors for help as the college is cheep and just uses blender) so if you can be bothered having a look, the file is attached (size limitations means no textures but shouldn’t be a problem, just ignore the errors).
By the way, this is a UK college, not the same as US college’s. Our US college equivalent is called university here, so its not that I’m a dumbass. In fact, the only requirements were to have 5 objects moving for 30 seconds or more, but for some reason I oppted for a big ninja assassination vid. The rigging is only about 1/3rd finished so don’t expect realistic deformations, yet.
Well, I have just tried the Spline IK Solver and it seems to fit all requierments (my excuse for only just thinking of it is that I only recently upgraded from 3DS Max version 7 to version 2008 so was not aware of it). It has built in gradual swivel controls and can move the bones in all directions, however, the point in using IK Solvers (for me anyway) is so that I will have to animate as few objects as possible, but I cannot think of a way to make all the point move easily (have tried adding a HI Solver to the points but that brings back the problem of not being about to bend the spine from side to side). So really all I need to know now is how to allow the HI Solver to bend in both directions. Surly this must be possible?
It´s not possibe to bend HI IK in multiple directions, as it is served as an amplifier for current rotations your chain allready starts with. So you are stuck with this initial setup.
For the Spline IK (which i was expecting to pop up in this thread sooner or later as I read it), you just need to ajust the amout of vertices the spline connected to the solver has. You don´t need to create a spline with as many vertices as the bone count in the chain. Create a Spline with 3 smooth vertices (or 2 Bezier Corner) to manipulate the global shape of the chain. As a result of the Solver, the bones will do their best to acomodate themselves along the spline. So, you have to worry about animating 3 controles or so, which, for a spine, is just fine.
Yeah, I suppose, just was wanting to get it to the point where I just needed to move a single object to control all aspects of the spine and shoulders, guess I’ll just use a simpler spline as you suggested.
I have got one final question tho, is it possible to link the swivel manipulators to external objects? Just so that I can rotate the shoulders and top of the spine as one.
Thanks to both of you, the help is much appreciated, now if only I had a tutor who knew anything I would be set.
You can manipulate the spline IK twist via Wire Parameter or Reaction Manager (or Scripting). What a Wire Parameter will do is transfer a value of a dymmy´s z_position controller to the SplineIK atribute responsible or the twist for example.
If you plan to evolve in this field I recomend that you star early to get used to Wires e Reactions managers. They’re the corner stones of many skills one should have when developing a rig.
