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marvelatthedust
02-08-2005, 02:33 AM
I recently decided to start a rigging reel for when I graduate, so as to be at least somewhat marketable, and I like to rig, from what little i've done. My problem is that i've looked arround a little and haven't found a lot of tute's on a quadraped rig... anyone out there able to help me?

thanks!

seven6ty
02-08-2005, 04:40 AM
Any specific questions about it?

eek
02-08-2005, 10:18 AM
Do a search for quadraped rigs, in this forum. I posted a few for max here, you could take apart. If you cant find them, tell me and ill post one up.


eek

marvelatthedust
02-09-2005, 02:32 AM
I am afraid my specific questions may show my ignorance, but as I am still a student, I hope it's forgivable :O
Questions would actually start at: where do I start? i am using a puma as my model, have not modeled it yet, but have made a diagram of where the pivot points should be along the spine and down the legs. I am very much aware that cats are very flexible, and so my rig will have to be able to reflect that, mostly by the back legs being able to cross the front legs when it is running, also having the legs walk in an alternating pattern, so the back left and front right are in the middle, whilst the back right and front left are extended, so how can I achieve those two effects with the least fuss?
I think that those questions are the first ones that come to mind...
I also hope that by so stating my extreme ignorance I'm not simply banned from the forums altogether...
thanks for the help!
-ian

seven6ty
02-09-2005, 03:42 AM
Nah, get used to it, you'll have to show your ignorance day to day if you ever wanna get good. :)

It's good to ask questions, and always good for the most detailed question you can come up with, so that people can give you specific advice on what you're looking for.

A lot of what you're asking about should come naturally if you simply check out a cat's anatomy, and where the hing joints of each bone lie. Also, something you may want to look into are automated scripts, that will make the hips and shoulders automatically dip and rotate when the leg/arm moves forward or up and down. This can be annoying for some animators, but for simple things like a walk cycle, they can cut back a lot of extra keyframing for you.

A good basic approach for the skeleton is to first do all the "spine" types of joints first, in one long chain from the pelvis to the base of the skull. Then, draw one joint below this spinal column for the pivot points of the hips and shoulders. Then you'll have two joints to each side of this pivot joint... for where the thigh bone attaches and where the shoulder blades pivot. Then down to the front of the shoulder blade pivot point, knee pivot, ankle and finger pivot points, for the front arms. Oh, and make sure all your local rotational axises on your joints are lined up in some uniform fashioin as well.

Yah yah, hope that helped. :)

eek
02-09-2005, 09:28 AM
ok,

1. Find a side profile of a cat skeleton (this is what i do), I always use a tiger or leopard. Then use it as the background in your side/left view. Match up the mesh to a rough/good position of the profile.

2. build the tail, spine, (between 3 and 8 is a good range of bones), neck, head, jaw, legs, paws, in the left view.

This is the basic start, also post a pic of the puma for us to take a look at. Is it based on reality? of a cartoony?

eek

joconnell
02-09-2005, 01:57 PM
I have a rig for a sabretooth tiger that I can chuck up - it's mainly fk along the spine and tail since that's what I was asked for but it might be a starting point for you - done with max 5.

joconnell
02-09-2005, 02:46 PM
okay, heres a max file of the rig - as i said it's quite simple, no spline ik on the tail or spine as the animators here prefer fk for doing rippled moevements. It uses IK on the legs to a point and then fk for the feet - bear in mind that cats feet are quiite different to humans in that the cat toes are the equivalent of human feet and the cat foot is quite similar to the lower bone of a human.

Use the rear hips null to make the cat prowl and lie down, the ik solvers to animate the legs and fk for the rest.

http://www.joconnell.com/cat_rig.gif

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