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pappy
06-28-2002, 08:13 PM
I have been trying to rig a quadraped (cat) and I have lots of issues that have me puzzled as to what makes a good rig. The biggest issue, right now, is how to incorporate the shoulders and spine into the rig. It was easy to rig a biped, but the four legged character seems to present more issues, like how the shoulders and spine interact with the hips. It is kind of like you want to have two parents of the spine. In motion, the hips drive the shoulders, but the shoulders are able to move independently from the hips, like when the animal is changing direction.
I have looked for reference for rigging quadrapeds, but there is very little out there. And what I have found has not been too great. Anyone have any suggestions, ideas or tips? Thanks.

neil

dantea
06-28-2002, 08:34 PM
Just thinking off the top of my head: Can we have two skeletons rooted fundementally different and then switch between them as the need arises?

pappy
06-28-2002, 09:03 PM
Originally posted by dantea
Just thinking off the top of my head: Can we have two skeletons rooted fundementally different and then switch between them as the need arises?

Well, it is a little like two separate parents, but they still have to be connected and, in some sense, driven by the hips. They can move somewhat independently, but if the cat were to jump, then they act more like one. When it turns, it acts more like two. When it sits, it acts somewhat like two. being able to lower the hips while the shoulders remain standing. Ultimately, it is a single creature, but mechanically different than a biped.

neil

eek
07-24-2002, 12:38 PM
Pappy,

I'll try and send you a rig ive got of a quadraped, its based on a rig where i worked. The most important thing is to keep the chest/shoulder seperate from the pelvis. But also have a control at the pelvis end which rotated them both. You need them seperate, because you need overlap. And as animals have a gait(time in air, and on ground) when walking, running etc. The pelvis always drives the chest/shoulders when moving.

Etc,etc

Eek!
heres some tests i did with a centaur character right- click and save target as-->

http://netdrive.150m.com/centaur_rear.avi
http://www.geocities.com/nette_pictures/centaur_walk.avi

Bilbana
07-26-2002, 11:03 AM
I'm also trying to rig a quadraped (a cat as well)

It would be nice if you could share that rig or atleast post some images and explaining how you went about doing it (since i'm not sure you're using the same prog) because at this point I don't have a clue
Hope you can help me.


also I couldn't view the clips i'm not sure why or if anyone else is having this problem, probably some codec missing...

Thanks

eek
07-26-2002, 07:12 PM
Hi Bilbana,

Sorry if the clip doesnt work...here's a side pic of a rig ive got of a dog. I dont generally use bones, but a light version of mesh sliced up as a control mesh. I'll show you:

Eek

eek
07-26-2002, 07:16 PM
You could also parent the pelvis, chest and head to a shape puppet( this is what i generally do) to control all of them also to do general positioning.

eek
**this i rig is made in max 4 but i know you can apply the same technique to any package, and with bones if you dont wanna use objects.:bounce:

Bilbana
07-29-2002, 08:00 AM
Eek

I try to do the setup you suggested but the bones collapses. I would really appreciate the file (i'm using max as well) if you don't mind so I can see what I'm doing wrong.
Check your private messages for e-mail

I really like the rig even though I didn't get it to work, once I get it to work it would give me just the control I need.

thanks

eek
07-29-2002, 10:52 AM
ok, Bilbana,

Heres a zip file, with the rig and and a walk cycle, of my dog. Its based on my own Dachsund, so its pretty acurate. Im trying setup a site with all my rigs on it and tutorials and character animation stuff.But for now here you go:(right-click and save target as:-)

Eek:eek:

eek
07-29-2002, 10:55 AM
Hi Bilbana,

Here's a walk cycle using the rig...

Eek:eek:

Bilbana
07-29-2002, 11:46 AM
Thank a lot that was really cool
Just one question though, how do you keep the model from seperating? the parts seem really hard to keep togetter espercially if you move the chest. Or maybe you don't it's not that big of a deal as long as you are aware of it.
Anyway thanks a lot it has definately opened doors for me, very inspiring.

Please go ahead with your tutorial it's guys like you who keeps this community on the right track, sharing and helping others.

/m

eek
07-29-2002, 02:27 PM
Hey Bilbana,

Here's a little test i did with the rig:
http://www.geocities.com/nette_pictures/dogplayingwithball.avi

as before right-click and save target as:-

Eek:eek:

pappy
07-29-2002, 11:17 PM
Eek,

Thanks for your postings. I have been working on this a while and
my solution was not a whole lot different from yours. I did need
more nodes the the spine to capture the shapes I wanted from
the movements of the cat. I have to add more controls to the feet
and then I will be animating it.

neil

eek
07-30-2002, 09:10 AM
Pappy,

Hey thanks,
The key thing is to not get bogged down , controlling the parts of the spine you just just need to control the pelvis or the chest, and not worry about the parts in the middle, another way i found is to do spline ik, and you can set it up in max 4, using path constraints.Ill try and post some pics soon.It mean you can get proper spine shapes happening through the animation the S shape.Anyway ill try and remember how i did it and post some stuff.

Eek:eek:

pappy
07-30-2002, 02:58 PM
Eek,
I have been using Max 5 for this cat. I have also been using a spline IK, but
I thought this was only available in Max 5. Have I overlooked something in
Max 4? Anyway, thanks for the info. I will check out the idea of using path constraints to control the middle nodes of the spline.

neil

eek
07-30-2002, 03:09 PM
Heres the spine-ik quadraped rig,
right-click and save target as:
http://www.geocities.com/nette_pictures/QuadraSpinerig.zip

Eek:eek:

samhodge
08-02-2002, 12:04 AM
eek the animation is the proof of how well your rig works

the other problem with riggin animals are the rump and forequater sections and how you bind them to the skeleton

anybody got any good ideas about this?

eek
08-02-2002, 06:43 PM
Rump and forequarter?? what parts are they??? Anyway ive got a site which is fantastic and what a base all my quad walks and runs etc on. Please take a look its FANTASTIC!

http://bowlingsite.mcf.com/Movement/Footfall.html

http://bowlingsite.mcf.com/Movement/locoindex.html

Its important to understand how the gaits work.

Eek

:eek:

MCage
02-16-2003, 04:32 PM
hi eek , sorry but i can't download the spine-ik quadraped rig

file from geocities.. link broken...

Can u help me ?


THX

p.S: i whant to learn :P

samhodge
02-17-2003, 03:39 AM
rump = the upper rear leg where it meets the pelvis

forequater= the front leg shoulder region where it attaches onto the rib page

wow do you handle the skinning in these areas

sam

eek
02-17-2003, 09:17 AM
Hi Sam,

At work everythings a patch model so we weight the handles to bones or controls. This would apply to shoulders, pelvic area to i think. Its just the way you skin it say 30 % to this bone 70% to that. I learned a good technique at work where by you animate the bones at say frame 20 then start skinning to you see how it works in movement and tweak where needed.

These places are always the hardest places to skin, shoulders especially! Just as lot of grease work.

MCage

here you go:

My dog rig and spine setups.. Most things are controlled by helpers and points.

http://www.geocities.com/nette_pictures/quadstuff.zip
(right-click save target as)

eek

TheShade
02-19-2003, 09:13 AM
Good stuff....Thanks eek

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