View Full Version : problem: rigging a tentacle

07 July 2003, 10:28 AM
by using constrains and parenting, how do i create a flexible rig for a tentacle. flexible as in minimum keyframing and maximum functionality for animation. i've tried distance constraining for a series of bones and by just moving the first bone, i have a nice wave principle action to the rest of the bones but.... i have to move the first bone back and forth in an "8" path. any idea how the similar effect can be achieved without moving the bone? as in animating rotation only without touching translation.

or anyone has another technic of rigging? the main point is to keep it flexible and like i said, minimum keyframing with maximum functionality..... u won't want to key each bone of a tentacle throughout the animation wouldn't u?

07 July 2003, 05:27 PM
spline IK is ideal for these situations.

07 July 2003, 06:09 PM
I agree with Fortner_m.

And make Culsters out of the curve CV's and animate the cluster.
I thinck you might want to animate translations, you will get more realistic movements out of the tentacle.

07 July 2003, 12:01 AM
Rigging a tentacle is something ive been looking into for the last few weeks. Like you have said, im trying to get maximum functionality aswell while keeping the rig as easy to control as possible.
The best way ive found of doing it is using a rig very similar to the IK/FK back setup Jason Schliefer put together. Basically Im using spline ik for all the tentacle joints, but instead of letting maya generate its own curve for the spline ik i create the curve manually. i did this becuase i want the tentacle to be retractable and to get sucked back up into my creatures body. So, by using a curve that is longer than the joint chain, this becomes possible just by animating the spline ik offset.

the second reason for creating my own curve is i wanted to leave a small group of joints at the end of the tentacle free of the ik, and just animate them with FK. (i want the tentacle to be able to wrap around objects and pick them up)
I basically think of the tentacle just like your average arm rig setup, so i create another joint chain that works as the control rig(shoulder,elbow,wrist joint etc etc). Then make clusters from the cvs on the spline ik and parent the clusters to the new control rig.

you can then move the bulk of the tentacle around with what would amount to be the Wristctrl, have it bend at the elbow, but then add custom attributes which drive the cluster positions to get various bends and kinks in the tentacle. then you are also free to animate the tip joints with fk.

there is a bit more to my rig than just that, its still not finished, but i may do a tutorial on rigging at the end of this project when its complete. apart from having about 20 tentacles, this critter im working on turns itself inside out. Ive worked out my own rig to achieve this effect, and its alot different to your standard bipedal character rig, so a tutorial on how i all works may be of interest to some people......who knows.........:curious:

07 July 2003, 01:35 AM
Hey very nice.:thumbsup:

Can you also put a with the tutorial? I would really want to see what it should look like.:bowdown:

07 July 2003, 03:18 AM
yeah i might put together a small QT movie of a bunch of tentacles unraveling themselves grabbing something, then dragging back inside the main puch they orignally came out of.

could be a while before i get to that stage though, and i dont have anywhere to put a link to the file..........:hmm:

im also working on a setup relating to texturing where areas of a softbody that are more "stretched" than others recieve different textures. i have an avi of it in action but like i said, ive got nowhere to put the file up.

07 July 2003, 03:37 AM
thanx for all the replies! especially to sandman! I'll really like to have a look at ur creature that u are working on.

my creature however looks like ..... uh..... i don't know what animal or thing to relate to.... it's out of this world..... but it does look like a huge egg/plant with tentacles for it's legs.... and.. and.. oh well, i might wanna post a sketch of it for ur understanding........ well i'm off to model it out first.!

07 July 2003, 12:17 AM
Hey funnydoodle your character sounds very similar to what im planning to do....I take no credit for its design however.

Im making an alternate version of the "Watcher in the water" from the first lord of the rings. Im using one of the designs from the book The Art of LOTR where the creature turns itself inside out for protection.

it kinda looks like an eggplant aswell! :D

07 July 2003, 02:56 AM
haha really? cool..... here's a lil render of what im doing now...... maybe u can post ur's too? a concept maybe? i guess ur's would like like a kraken?

i like lotr monster concepts too but i'm more inspired by h.r. giger's art and designs.....

i've already thought of a way of rigging the character but suggestions and ideas are still welcomed if there's any.... who knows, i might not have heard of them.......


07 July 2003, 07:27 AM
oh my god that thing is crazy! how does it work?:D

this is the critter im doing, but again, i didnt design it.

sorry the quality is so bad.

07 July 2003, 09:56 AM
lol.... yeah quality is so bad,..... but i think i can make out what it looks like...... look forward to u finish that character......

well uhm.... my character..... as u can see it has 3 sections and another at the top which is the arm with fingers.....

the "mouth" of the first section at the lowest opens to another section and the second one opens to the third and it opens to the arm....... i hope u understand....... lol..... so at resting pose, all the part from the 2nd section up is hidden inside the first section.... it's concept is like giger's alien when the mouth opens to a smaller mouth...... just that my character has more mouths.... hehe......

and the rigging is gonna kill me...... lol.....

07 July 2003, 12:43 PM
thanx 2 everyone who helped!! i appreciate it alot.... now that my character is done..... it's time for critiques.... for those who are interested, i've posted the pic and test animation in a new thread at the wip/critiques section..... the link is

07 July 2003, 04:10 AM
hey funnydoodle, i finally got around to putting together a simple test version of my tentacle rig in action.

not very exciting but i thought id post a link to it anyways for people to look at it if they want.

maybe ill start a new thread once im a bit further into the project

ill explain it once people have seen the file....

you will need DIVX to view it aswell

and here is a much better quality version of the concept illustration for the critter im actually making (I TAKE NO CREDIT FOR THE DRAWING OR DESIGN!)

07 July 2003, 05:58 PM
not really clear whats going on but i can tell there's something going on there....... i don't know how to describe it but it sure looks like what we both have in mind... be glad to see more from u..! i've added more animation and pics on my thread as well.... check it out!

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