rigging a caterpillar in xsi

[carlsden]

Hi guys,

I've modeled a caterpillar in xsi but rigging it has been a nightmare!
is there anyone who could suggest the best way to rig it?

i want the caterpillar to move in a realistic way so i want each section of the caterpillars body to follow after the one in front....

its proved very tough so far.

I tried a group of disconnected bones for the spine and tried parenting it to a master bone, but i ended up not being able to parent the separated bones to a master parent bone, cause each time i try it the bones move to where the master bone is....

here's an image of the caterpillar and the bones
http://img252.imageshack.us/img252/3381/snapshot1bi5.jpg

[Michelle_d]

a breakdown of the rig can be found here
http://i23.photobucket.com/albums/b351/Wendy_girl/Untitled-1.jpg

Each spines root is POSITION CONSTRAINED to the effector of the next spine.

Each leg is drawn backwards, this means the root is the foot and the effector is by the spine. You can always add an extra leg bone (two-bone chain) for more flexibility for the feet... perhaps???

The legs effector is position constrained to the effector on the spine, and that same effector on the spine is then position constrained to the leg effector. Note that this is not perfect, because when you move the leg root too far the effector of the leg detaches from the spine.

I reversed the leg bone so the feet stay planted as you move the other legs, or body. The spine is set up the way I have it so that I can translate the last root and slide the whole body forward... I primarily did it this way because I wanted to show off how I would set up the legs, but it may not translate to a natural movement for your character.

It's not a perfect rig, I'm still trying to work out some bugs but maybe it will give you some ideas.

[Michelle_d]

Wireframe


VIDEO (http://www.youtube.com/watch?v=AfJuDemQ3C4)
different wireframe/background contrast
Video2 (http://youtube.com/watch?v=ICKF42KXThs)



That is the link to my youtube video of the rig.

It's made using the instructions above.

video with a mesh (http://youtube.com/watch?v=wBwqBVg0pk0)

On this rigged mesh the spine was a bit high and the legs probably too long as a result so the body tends to crimp more near the bottom.
Also I should have added more bones to the spine because while it does line up with the legs, it doesn't line up with the segments so I get crimping above each leg and not between.

[carlsden]

hey,

thanks a lot for that reply... unfortunately i have already finished rigging and animating the caterpillar... i did it by manually keyframing each bone... long, but worked in the end...

here's the finished animation.... wans't as good as i wanted it to be but i'm done now and i've submitted it.... waiting for the results.... :)

http://s283.photobucket.com/albums/kk305/carlsden/?action=view¤t=finalefaforweb.flv

[Michelle_d]

Link Test (http://s283.photobucket.com/albums/kk305/carlsden/?action=view&current=finalefaforweb.flv)

I tired your link but it sent me to my home page on photobucket so I'm trying this one

Anyways how did you do the morph, by scaling two different meshes?