war of the worlds bone help!

[rustythe1]

well this maybe the first time i have come to ask for help in these forums, but i decided to try and animate a large model i made a while ago, this would be the first project i did to introduce myself to bones and ik, i think that maybe it could be a big one to start off with but think i did a good start, basicly i managed to get the legs slightly poseable but i now want to create a walk cycle (an animation i stuck on youtube recieved alot of interest so i thought i would do some more)
the problem is the legs do all sorts of weird things when they are lifted beyond a point, first image shows that low down its not too bad to pose, the second shows that suddenly the leg will flip, i have set limits on all the bones (which are quite low, between 10 and 2 deg),there is a large bone through the foot which is attached to a null, you can also see i have drawn a red line where i would like the leg to go,also i cant seem to keep te foot verticle, i have set limits but it seems to ignore them when parented to the null, may be as it has to keep the goal in reach,
the foot is less important as it would be easy to key frame but i would like to keep the leg a sweeping curve down in line with the foot as it tends to kink a lot, any help would be most greatfull,
also would like to point out that some one suggested ik booster, i could see how this might help but it dose not seem to function in my 9.6 64bit?
i can open an option window but it looks nothing like any of the tutorials i have found? and dose not seem to have the right click menu?

[evenflcw]

Did you prebend? Ie did you give each bone a rotation on the first keyframe indicating whether it should rotate toward the negative or the positive? You need to prebend so the IK knows which way you prefer it to bend, it can't decide for itself. If it still flips, try prebending more. If you'd like it to bend the other way later on use the pole vector or Base On Most Recent Keyframe option (LW9.6). Another option would be to use plg_curvebone (3rd party plugin) which is a multigoal splinebased solution which commonly will give a smoother solution.

[rustythe1]

no have not herd of pre bend,will give it a look up (i would guess you jest set a key frame that has slightly moved from the rest position?) the plugin looks like it could help, hope it works with 9.6 64 on vista,
thanks for the quick response, and more ideas welcome in the meantime (i would like to learn as much as i can as i think this would help with many applications)

[SplineGod]

IKB works fine in 64bit. I would also go that route as well. IKBs IK behaves much better then LWs IK for long chains of things and there are other controls that make it nice to do something like that.

[rustythe1]

hmmm i still cant get ikb to apply to the bones, do you need to remove ik from the scene, i only seem to be ably to apply it to a handfull of layers in the scene but none of the layers i actually want it on,

[SplineGod]

If you already have IK applied to somethings in your scene IKB will not effect those channels. Anything in the same heirarchy will be effected by IKB once its applied to the root of the heirarchy.

[tischbein3]

the problem is the legs do all sorts of weird things when they are lifted beyond a point, first image shows that low down its not too bad to pose, the second shows that suddenly the leg will flip, i have set limits on all the bones (which are quite low, between 10 and 2 deg),


If you do not want to use IKB, turn of limits, and add an additional knee target Null, adjust he upper chain to it (you might need to use align to path / pint to target) and parent the knee null to the Leg Target / move it to a position, so the knee bens correctly.

A general rule of thumb of lwik is, to use at least a null target after 3-4 ik affected bones.

my 0.02

chris

[rustythe1]

well i still got a head ache, i thought i would upload the object, if anyone wants to have a go or a look at rigging feel free to download, the tenticles are missing but you can download the full object at foundation3d, also i had to use some trickery as its a big model, i compressed it too a rar then compressed the rar to a zip and it only took 5 megs! just as a rar it was over 20, and sorry the images are in psd (why i forgot to png them i dont know)

[rustythe1]

by the way the tripod is the one in my avatar!

[rustythe1]

also forgot to mention, i want to be able to walk up straight then walk down into a crouch, like on the film. the way it is rigged at the mo it probbably will be able to walk up right with not too many problems, just some niggles with the feet.

[SplineGod]

One thing that youre going to have to deal with ist he high polygon count.

[rustythe1]

yes, the legs add most the polys, this is one of my early models i have made in lightwave, i could probably do a better job now, but my system seems to handle it quite well so i have not worried too much about it for now (i still tend to over model stuff but i like all the detail and trying to make it as close to originals as i can)

[rustythe1]

did you ever do a tutorial for the swan set up on your site? had a play and it seems to be set up near enough exactly how i have, the null at the ankle controls positioning and foot direction, like your head null, but no mater how you move your rig the neck moves up, where as mine bends down,(i even split your rig into 30 bones and it still worked!) i tried a rest rotation, all the way up to 180 deg, im thinking may be i re model the legs in thier bent up position?

[rustythe1]

well i have remodeled the legs in a new position and also reduced the polycount by 40,000 in doing so, i then re rigged from scratch and now it seems to be working a lot better, have gone as far as making one walk cycle but i have a question (as i am not to up with any time saving shortcuts in layout) is ther a way i can copy all the keys from all objects, move them up the time line then add 30 meters to the z plane values? i have watched a lot of tutorials on walk cycles but the way i have rigged this model i cant apply those methods to this model, i have rigged it so the feet work from world cords and the head moves on its own, this alows the ik to work well with the legs meaning the body can be moved and the feet stay where they are set, so my walk cycle involves the head moving at a steady pace and then placing the feet where they need to be,