View Full Version : A plea for help with my Rig!

09 September 2005, 11:15 AM
I need help - badly! My rig is driving me to the pits. Firstly let me explain my dillema - and then ill go into what i have. Its nearly brought me to tears on many ocassions and i cant mentally deal with it anymore - making it even harder for me to think of ways to go about fixing. please bear with me as its been a very long few months and MANY MANY things were attepted.. to many to recall in this post - but will try to point out some main ones.

BEWARE - longest post ive peronally ever seen!

- LRA (local Rotation axis)
- Skel (Skeletion / joint hierarchy)
- HI (hierarchy)

about 4 months ago at course we started rigging. I have since learnt the workflow which suited the course was not the most ideal.. and im paying dearly for it now. Think of it from the point of view of someone not knowing how rigging works...

We started with building a basic skeleton, we we aligned the LRA so they suit how our characters body move. here was the start of my problem. i dint realise the importance of how the LRA's affect the whole process .. like IK's, contrainting of muplite joints etc. So although i did align them how one should for movement (eg leg forward = 1 axis, not 3) but not to suit processes later.
Most would say ok.. so you did a mistake - export import weights till its ok.
I did this serveral ocassions and was great - Until my maya failed to import the weights back in properly - why i dont know, and have found little to suggest why my scene does this over the last few months.

This left me with a skeleton that could potentially have problems with skin i could not remove.

It was then at this stage that i managed to use a script from highend to export and import my weights.

My setup design revoles around a 3 skel setup .. 1 for skinning, 1 for FK , 1 for IK. low poly geo cut up for skinning driving a hi res wrapped mesh.

the concept was to then diplicate the skin skel then orient the one to as masters to the orginal skeleton. Dis was done.

It was then major problems really started to develop. one with maya solving IK's badly. We ended up rebuilding the IK legs so they were ok which solved that problem. however they didnt not start perfectly ontop of the orginal an fk equivent -something im not too sure about but think is a natural thing when applying a solver.
then the next problem arose with constraints, and the need to use offset due to the non matching Skels. My rig started to perform various flipping problems - espically in one particlar point around the leg. In a way that did not make sense. Turns out there is some form or matter of rotational infomation passes down the hierarchy from joints higher up. Sure enough by then modifying the FK skel (same as skin Skel) upper joint seems the releive the problem to something usable.

Gaps in lessons then further caused confusion about how the rig system is ment to move and be animated - with my rig not having proper control setups and me continuesly having to change -wearing me down more and more.

to add my first animation final project was seriously handicapped when my 5 beatiful walkcycles would not import onto the same rig to combine them due to limitations of the anim export in maya/ pairblend nodes (i think, to this day not certain about it)

not somethign you want to learn about 2 days before 30secs of animation is due and on import the charcter anim moves more like a zombie with a half paralyzed body!!
However I managed a pass - something that im annoyed with on a personal level as i had to day achieved dinstination in all my work - as i had failed my goal to do the whole course so.

Along came my next assignment. This one ment the chacrter had to turn around in world space. I started to animate and block it in, moving the global node at the top of the HI. As i had seen in the gnomen walkcycle DVD. It was quickly apparent that this was not really how on should animate as then feet will slide upon turning the chracter. So i then tryed turning the charcter under the node - and i couldnt...i controls didnt let me.

I then rebuilt a major part of the rig with what i had learnt and thought i now had a finished rig. WRONG

i setup the controls afta opening and studying rigs such as leon for CG toolkit, as watching the DVD in how he was put together, made me realise the gaps in the video - such as how one setups up the hip and cog properly.

I tried again to setup - an now.. finally, after all my trouble - my rig is still useless. The legs now flip 180 deg. Upon trying to fix with literially many experiments - i cant work it out. I think at one point in a new file the duplicate joints as they were worked - but in my scene they did not.

SO.. here is my plea - i have ideas on how to fix this now too.. but cant fantom any more more "i think i know's". There are aspects dat i simply dont understand - such as issues with offsets, why my skinning is fallen over etc. The best thing for me seems to rebuild the base skeleton. but seems the highend scripts (those that let me take of the weight off dont let me import onto a new skeleton (even if identical in design and naming).

So i ned to correct what i have. But really jst cant keep guessing in whats wrong.

Im exhuasted with this and upset as im not one to be a rigger.. but would just like o animate. however i got to school and sit there fixing my rig, watching everybody slide their characters around. I guessing im not the only person that would have extensive problems with this if one tried to not do things by havles , as im one not too.

i however quickly get lost with the more technical insight into the makeup and relationships of the art of rigs. Probably where my solutions lies.

I fear as excellent and wonderful my tutor has been - the fact the school im at still only have one appointed tutor for all topics, its taken its toll on me.

I now cry out to anybody that has made it to the end of this to help me with my dilemma, shed any insight into my complications or anything related to this post. PLease! feel free to ask me further into any aspects that i may have made vague (as yo ucan see by then length off this post ive really tried to covered my process ive been through)

Also to help even more i have attached my rig. As it stands this is as far is i got with it. there are still other aspects of it missing such as the ik fk controls for blending hence the 3 skels all in differnt places. Simply rotate the cog controller to see my problem. If i can get insght on how to fix this - without massive overhauls - i would be so grateful, it be bordering on quite an emotional level. i have removed my geometry as i believe the ultimate solution lies in simply fixing the rig as it is.

File is saved from Maya 7.

thank you. I know if there is someone that can help - its the amazing people that visit this forum :)

09 September 2005, 02:16 PM
Hi revilo3D,

As much as I wana help, I think it will be easier for me to look into how to solve your problem if you can describe your entire workflow of creating this rig up till now. From there, I could try to see where and maybe what went wrong.

Currently juz by looking at your rig, I can see that all the joint orientations of your 3 skeletons are totally different, which may be the cause of the problem to a certain extent. How did you create the 3 skeletons? The usual workflow would be to create one, and duplicate it twice so that the positions and orientations are entirely the same. Did you do that too?

Sorry if I can't help much, but I would try my best to do so.

09 September 2005, 03:34 PM
well i sorta tried to describe that :P.. is diffcult becuase of so much that has been done in attempt to make it work..along with learning things on the way. Im amazed i got as far as i did.

we basicly built up the base skin skel and skinned. I then duplcated this x2.. howver the Ik started to play up due to bad LRA's and becuase i at the the time had difficulties (probably prior to workig out how to overcome skinning export import problem) we modified the Ik LRA's so it would solve properly. With the idea that we could constraint with offset.

this solved the IK problem.

The i noticed problems with the FK rig. It was at the time the same as as the skin rig. However upon contrainting via orient constarint the three together, the joint on the skin skel would flip. after digging it was apperant that the FK seemed the problem. Recreating a section of that fixed that flipping problem. To be precise from what i recall - the culprit was the plevis joint on the fk making the leg flip!

""Turns out there is some form or matter of rotational infomation passes down the hierarchy from joints higher up. Sure enough by then modifying the FK skel (same as skin Skel) upper joint seems the releive the problem to something usable.""

So finally i guess the result is 3 skeletons with all different LRA's. Now the trick is what is this flipping and want makes it occur - espeically in using offset on constraints.

Im guessing ill have to fix the skin skel and rebuild the other two setups - but i need it so i have fk and ik works both in the own realm how they should. And as you say "cause of the problem to a <<<certain extent>>>."

I guess i just need some solid info on whats going on.. as i dont trust any ideas i have anymore. everytime i go with them it bites me twice as hard in the next step.

lol.. becoming quite the expert on the "dos and donts" as everything that could go wrong seems to have done so for me. Very hard way to learn.!

10 October 2005, 06:25 PM
dude, i hear your pain. i'm trying to learn this myself from books and such, and i had a lot of problems just doing two rigs. in the end what i did was build a full hires rig, when i got that skinned and working nice, i then started lopping bits off and simplifying to get a lower res rig. all your LRA's are right and constraints should work if you want to animate that way. i'm just importing low res and hi res animations onto the skinned skeleton and it works fine. HOWEVER this is good ONLY if you're the modeler/rigger/animator. it is not production pipeline, that is, i suspect one of the ways your workflow is trying to attempt. anyway, want to see more from you soon...


10 October 2005, 06:38 PM
Your LRA's are really way different across the entire skeletons. This is causing the rigs to go AWOL on you.

The other thing is that I don't see any of the contraints between the rig.. you're using Paul Thuriot's setup which in order to properly transfer the animation requires the connecting attributes such as boundAttr etc (more info on the DVD). This is what is used to string your animation from your blocking character to your medium res and then to your final bound mesh.

3 Skeletons for an entire character is pretty wild too... the point that Paul was making in the DVD is that the lowres skeleton would be something you could hand off quickly to an animator with a straightforward set of controls and they could start blocking/posing. Then you start adding the finer points of detail eventually leading up to the boundRig.

Having 3 skeletons like that in the scene is REALLY gonna get confusing... generally you would only see a 3 skeleton setup for arms, legs and spine (ik->fk switching).

On another note, I'd suggest making the controls visibly different as I couldn't tell what controls were what in the hip section cuz they all looked the same!



10 October 2005, 10:04 PM
I think maybe ive been misunderstood about the three skeletons -but maybe not. the rig has a base skeleton, which i skin the character to. Also this has a cut up LowGeo parented to it. Basically its a hierachy that drives all the geo. My highRes Geo is wrap deformer driven.
The other too hierachies WERE duplicates of this, on with IK controls (ie rig was simplifyed down too only arms and legs) and a FK skeleton. My spine is FK driven.

controllers are added for each "rig" skeleton which i then setup chacarter sets for. This i believe allows the skeleton which is skinned to be only driven via the constraint to the FK/IK vesrion (ie IK/FK switch) or just the Fk in place wher no IK joints exist/are needed.

I know my LRA's are different due to issues i had was with how i made my orginal skin skeleton -and due to the problem of not being able too at the time take the skin off anymore (unknown problem which at the time was unable to solve - An still cant to an extent) has made me had too change LRA's on the other too to stop various serious porblems i was facing.

This lead to my question about constraints with offset and how the joints would flip when i turned the character.

That aside - i can say that my flipping problem has been solved!!! with one click of a button thanks to my good friend Worzel having a play around and stumbling on it.

By changing the Inter Type of the constraint solving too "Shortest" my problem has vanished..

PS.. saw your reel man.. some very intresting critter uve had to deal with there :) ... however would have been nice in the reel to see a little bit more of the underlying setups that you did for some of those beasts :)

Thanks guys :)

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