CAT Rig 3ds Max
polycounter lvl 5
Hey guys, sorry if this has been asked before, I have searched the forum and couldn't find anything.
So I've made a CAT rig in 3ds max which I've skinned to a dinosaur mesh. The problem I'm getting is with the legs. When I try to animate a walk cycle the legs sometimes freak out and I get really strange rotational values on the leg bones (but not the foot which contains the keyframes).
I've opened my curve editor and tried to manually change the rotation values but it doesn't seem to help in every circumstance. Is there a way to prevent a bone from changing it's rotational value? I looked on Autodesk's documentation and there are ways to lock local rotation etc but they don't seem to work =( Any ideas?
Thanks, steve.
So I've made a CAT rig in 3ds max which I've skinned to a dinosaur mesh. The problem I'm getting is with the legs. When I try to animate a walk cycle the legs sometimes freak out and I get really strange rotational values on the leg bones (but not the foot which contains the keyframes).
I've opened my curve editor and tried to manually change the rotation values but it doesn't seem to help in every circumstance. Is there a way to prevent a bone from changing it's rotational value? I looked on Autodesk's documentation and there are ways to lock local rotation etc but they don't seem to work =( Any ideas?
Thanks, steve.
Replies
Are you using the built in dinosaur CAT rig? I can't repro the issue with that. I'm using 2013 though. If you altered it, maybe you can post your rig file?
You can try turning on the Up Vector, which might help stabilize the leg. Select the leg and go to the Modify Panel and look for a button labeled Use Up Node. This will create a helper at the knee position, which you can use to point he knee with. I've found this is merely a suggestion though, as you can still break the IK for some reason.
Also, collapsing layers can add bad keys to the legs. These can usually be fixed by going to the first frame of your anim and deleting them. I fight this stuff every day. I hate CAT.
It's not so much the IK as ALL OF IT.
It might be a nice animation system, but I don't know because I can't get it to not crash. I'm not joking when I say it crashed on me when making the allosaurus preset to look into this problem. We evaluate it as an option with each Max release, but we haven't gotten past the crashing.
Pretty much. CAT's presets have been notoriously flaky. I don't think Autodesk updated them after the "rewrite".
Also e_x I tried what you said and it's still playing up unfortunately. If I can't get this working, what would you suggest I use instead? I'm using BIPED before but i'm not sure if that can be customised in the same way or not?
Thanks for you responses too
I managed to get it pretty stable using a Up Node and tweaking the timing of your anim. One thing I noticed in your animation though was that you had the leg extended beyond the IK length, which is never good, so watch out for that. There were also a few frames that just seemed bad, like frame 18 for instance. What I did was just move the foot up or down until the IK unfucked itself and set a new key. Then I retimed and tweaked a few poses and it seems better.
But anyway, here's my adjusted version if you want to reference it
https://docs.google.com/file/d/0B5FyLtFhZNqqNGNzSmhOR3BLcnM/edit
Oh, and you could probably build this rig using Biped if you had to. I believe they added a horse link leg a while back, so you should be able to build those legs no problem. But you lose Euler curves in Biped, so there's a trade off. Building a custom rig is always the best option.
Really appreciate the time you spent so thank you again and happy animating