View Full Version : One Human Skeleton Good For All?

12 December 2003, 09:54 PM
Once I've got a skeleton for a humanoid character nicely rigged up (with the controls driving the right connections and setting the driven key and all that,) is this skeleton then good for all my human characters no matter their shape and size for the rest of time?

What I mean to ask is, is it a fairly simple process to simply stick my joint system under another model, stretch the joints to make them fit the new character - hit auto-orient joints/freeze transformations - and bind it?

Sorry if I sound lazy, but if I go through this heart-rending process of getting my joint system working for my female character, and then I've got 4 other characters - all human - for my little animation...i really want to know how to get some mileage out of that first effort on the other 4.

(so then my follow-up addendum will do I get all the weights successfully transferred if that's even possible? Do I have to pay attention now at the modeling stage to make sure that all the vertices relate to the same body part or use the same naming system or something????)

12 December 2003, 03:20 AM
whoa i thought this would be an easy question...:hmm:

12 December 2003, 02:01 PM
Itīs a tricky question that most probably the answer will be NO.

Since u r making sure that the characters stay equal they might work, but if they dont, usually few refinements to the Bones positions should do the trick.

Weights are another problem, but i think u will have to paint those on all the characters.

12 December 2003, 01:35 AM
do i have it correct that i can simply move the joints to the correct position in the new body, then once all positioned freeze transformations from the root back joint, then auto xyz joint orient also from the root back joint, and everything should be hunkey dorey?

...or am i missing something in there? i basically want all my set driven keys to work, and my controls with customized variables so i don't have to make all that crap again for a character that moves and acts the same but is just a different size.

12 December 2003, 08:21 AM
It gets tricky slapping an old rig on a new body. Depending on how you set it up, it could be easy or a nightmare. I've had both. easy when the character has the same proportions, nightmare when they dont.

In my experience you will have to partially disassemble the rig, reposition, and rebuild some of it.
Sometimes it takes the same amount of time to adapt a rig than to rebuild, so try it and see what happens.

There really is no easy answer.

12 December 2003, 03:33 PM
yes experience is now beginning to tell the story, and the ACT II of that tale is that the problem comes with all the interconnections i've built into my first skeleton rig with all the controls and ik's and all that crap. you basically have to take it completely out of itself and disconnect all connections to be able to freeze transform once all the joints are moved around.

i'm just going to start from scratch again right now, and i think it will go faster for virtue of experience than trying to cheat my way. that's a shame though, but i think ultimately i'll develop a standard "woman" sized rig, and a standard "man" sized rig, for all my normal human characters.

12 December 2003, 10:05 PM
you could write a mel script that automates it for you.

I just finished my first one, and man... how exciting. I put everything in, and it's now fun to rig.... except for weighting. ...cant give it up, cause it belongs to the company I'm at.

Good luck quiz

12 December 2003, 12:30 AM
yeah i think getting into all that MEL crap right now would be just a little on the overwhelming side for me right now. I have to first get my mind around manipulating the rigs the way i want and get these bad boys & girls running and jumping around by tomorrow or so.

i've got a storyboard worked out that really kicks ass, and a cool rendering workflow for the look...and it's short enough to possibly get done. We'll see...

12 December 2003, 02:25 AM
folks, ever had this? you go to add ik handles to a joint and it always flips your joint to the side...everything is started from scratch, or so you think - but when you check out the settings for the ik handle there are all kinds of other solver types loaded into the drop down menu (ikSCsover,ikRPsolver,DetachedRig_ikRPsolver,DetachedRig_ikSCsolver, and ikSCsolver1) and the Detached sovers work properly...very random and irritating.

Where in the f**k did all these extra solvers come from in Ch****'s name?! and how do I get rid of them???

sorry 'cause i'm a little frustrated right now, i don't really blame any prominent religious icons for the user problems i'm currently having...

12 December 2003, 03:00 AM
ok relaxing, logical thinking...i'm trying to use the SCsolver. This means that it will line up my joints along one specific plane. Does anyone here know how i can determine which plane it uses for lining up my joints? Now it's using the x plane, and i want it to use the y plane.

12 December 2003, 03:27 PM
when i add ikspline solver to my back joints, should that straighten out my spine? I don't think i want my spine straightened for me, but if that's normal and that's ok then i'll run with it. otherwise something's wrong...

12 December 2003, 03:30 PM
ok, i took off auto simplify and that solves it, but now i wonder if i am missing some functionality by not having autosimplify...

12 December 2003, 04:29 PM
this is so ridiculous. i follow the instructions by Alias exactly but it just doesn't work. nothing works.

12 December 2003, 09:40 PM
which instructions from Alias?

I hope it's the instructions on the 1st schleifer DVD. If you don't own it, you should. It has singlehandedly changed my life for the better.

It so sad how true that is.

12 December 2003, 10:20 AM
I am using the tutorial based book "Learning Maya 5: character Rigging & Animation" from Alias. It walks you step by step through the process of rigging a human character using their tutorial character Melvin, get it? MEL-vin, hahaha. (ok, i know it's not that funny, but hey i'm stressed.)

I've already done the entire book once just using their character and learning all the stuff. Now I'm walking through it again to rig up the characters for my game characters short film project. It should work, and for the most part it does, (except for those issues mentioned above which i already solved - more or less)

The problem i'm having now comes when i try to parent constrain the back_root joint to my hip control (basically my mother joint.) They say I need to do this so that when my cluster hip control system gets translated that it won't tear away from the overall joint network. Ok, understood. but when i do this the entire skeleton rotates undesirably. Very, very frustrating when what I want to do is animate and not sit here rigging for the rest of my life.

I'll post pics...

12 December 2003, 11:00 AM

I can only assume it's to do with the fact that somehow my back_root joint has a translate value before i slap the parent constrain on it, but why? i had frozen transformations on the full skeleton way earlier in the process, or so i thought.

12 December 2003, 11:23 AM
somehow it's rotating the x value of my back_root joint when it gets the parent constrain from the hip joint. see in the picture how the jaw and the foot joints now point the opposite way? why would it do that?

12 December 2003, 11:44 AM

12 December 2003, 01:36 PM
You need to create a null node by grouping while nothing is selected. Then orient and point constrain the null node to the back_root joint so that it has the same position and orientation as that joint. Now deleten the constraints and parent constraint your back_root joint to the null node. It shouldn't flip because its got the same orientation. Now parent the null node under your control. This should do the trick!!


12 December 2003, 02:47 PM
thanks loked out! you're the man. it didn't quite work out exactly the way you said, but by playing with the null node i've got it acting the way it should...

what happened was this. i created the null node like you said. point and orient constrained it to backroot then deleted the constraints. this all worked like a charm cause i could even see the axis match up to that of backroot's, cool. so then i go to parent constrain backroot to nullbuffer and guess what? it flips 180* just like it's always been doing with hipcontrol for me before. So I'm laughing my ass off to myself thinking about alternative career options that might be a bit more forgiving of the limited intellect demographic to which i belong, then i parent constrain nullbuffer to hipControl and bam! backroot flips 180* again and everything's cool. I'm not even going to test it now - i prefer to take it for granted. i'll just write this e-mail to thank you loked and move on to building my hand joints and controls - if there are undesirable consequences to this seemingly backwards method of getting the thing parented under there i really don't want to hear about it until after the fact. So write your answer here with no worries cause i won't be checking it again anyway until sometime later this evening or tomorrow.


12 December 2003, 03:12 PM
ok remember i said i wouldn't look or come back here 'til the hands were done? well f' it i couldn't help playing around with the local and global controls, which thanks to loked are in fact working perfectly and their working state in fact leads me right into my next question...

it's obvious with that picture that the arms don't follow the body. this is because the wrists are point contrained to the wrist controls which are those box shaped objects at her wrists in the geometry.

i just want to know if this armstretch thing is the normal way the human skeleton should behave prior to animating or should i be getting those wrist locators to move along with the rest of the package?

note also that the feet locators also don't move along with but that's supposed to be that way, so that's why i am thinking that maybe this is ok for the wrists as well...but if i'm wrong please let me know.

12 December 2003, 03:22 PM
Its completely up to you. You could either leave them like that and then you dont have to worry about counter animating all the time. I prefer this method. So if you animate the chest and then animate the hands and then decide you dont like where the chest is, you can just move the chest and the arms will stay where they were. You can also setup a switch between the two methods. They way you would do this is a little more complex and can create a more complex rigs. You might just be better off using one or the other. If you want the arms to follow the chest area, just parent them under. You might get orientation problems again though. Let me know if you do.


12 December 2003, 05:20 PM
hey loked, no way i don't think counter-animating suits my personality one bit. i'm really a top-down kind of guy (like big obvious details in place first and then increasinlgy detailed levels of refinement) and i can see lots of last minute tweaks in my animation future. if every tweak adjusts the position of my hand which is say - locked properly in place at some baddie's throat and then i rotate her chest a bit to get a better angle on her protruding womanhood and the hand moves away from the throat? way - nightmares just thinking about it.

i'll hit you up for sure for that more complicated double in-between riggie deal after this short project is hopefully completed. then i'll want to rig up a higher-res version of assassion chick.

12 December 2003, 05:40 PM
the time noted on this post is my start time for the hand joints. i should have them operational and attached to the body on both sides within 2 hours. i'll post when done to note the stop time.

12 December 2003, 07:54 PM
stop time. everything working on the hand controls.

12 December 2003, 07:56 PM
:24 overtime. never under is it? always just a bit over...oh well no complaints here it works and i didn't hit any unexpected roadblocks.

omg! I can go to skinning! I think...let me just play with the full rig a bit and see if everything is REALLy all working.


12 December 2003, 08:10 PM
ok, i think i already see a xchism. but maybe one i can live with.

the new hand controls are parent constrained to the hand_root joint. because i've got wrist controls that don't conform to the body translation when i move the wrist locator it rotates that joint and therefore the hand joints as well, this causes my hand to rotate as well...i think, not sure i'll have to look more closely

i'll take a break, give my girlfriend her two minutes of quality time and once she's asleep i'll be back here with updates.


12 December 2003, 04:43 PM

don't laugh. please.

i'm rigging up this low-poly character using smooth bind and max influences 3 to fit game standards.

two questions:

1. before i saved my work and reloaded it the skeleton wasn't imploded on itself like it is now. well it's maybe not that bad but somehow the chest cavity and shoulders crushed in on itself and i don't really know why...any ideas?

2. Is my painting weights approach appropriate? Like position the chick like this, paint weights from various joints iteratively until it all just looks the way it should in that pose and then move on to other poses? When i re-paint weights when she's in a different pose doesn't that affect the look of the original pose?

oh, yeah another question:

3. How about if i want to mirror weights? Do i then just only paint weight influences on one side? meaning don't touch joints on the other side while painting the weights? Cause right now i'm kind of just randomly choosing joints that influence and just painting until it looks good without concern for what side of the body the joint is on.

Starting over is no problem for me. Just please suggest the most effective method that i should go about this. Thanks in advance.


12 December 2003, 04:52 PM
ok, ignore question 1. i already figured out it's because i had iksolvers and constraints disabled in the evaluate nodes settings, and when i restarted my computer the original preferences came back.

only thing is, even when i re-open the file with those settings turned off again the chest is still caved in. any way to get it back the way i had it? doesn't too much matter i'm going to start over the painting again and this time i just won't turn off my computer...

...but could you please let me know if there's a special way i should go about this painting of weights if i intend to take advantage of "mirror weights?" do i need to stick to only one side, or can i still have "left hip" influence CVs in the right hip area (for example)?

12 December 2003, 09:18 PM
ok i think i see it now. my workflow needs to be: position character in extreme position, paint weights. constantly change position and paint weights until the influence balance is optimal (as optimal as it's going to get) for all positions for that shoulder or hip or whatever. Keep my painting strictly to one side - except for 0-axis joints on the spine, mirror everything when done while character is symmetrical.

is this correct?

if so, i'll start over again (for the 3rd time) and hope it works. i wish i could see someone's game model properly deforming with roughly the same amount of joint influence (3) i'm using to have a reference for how optimal it's gonna be able to get - to avoid over painting 'cause i think it's not good enough when it's not going to get any better than it is...

any ideas, please let me know.

12 December 2003, 02:54 AM
ok, the paint weighting at this point is entirely not optimal. is this standard for low-poly game characters?

is it a no-no to just go ahead and start animating my characters and worry about finishing up the weighting later on during the process? (since she looks good enough at this point to animate)

Animating Weighted Paints. Does such a concept exist? Since it seems impossible with only 3 joint influences per CV to create an optimal weight balance that looks good in all poses, is it farfetched to consider animating the whole sequence, then painting weights at each of the key poses and setting keys for the painted weights so that they will adjust during the animation?

Please let me know if this is a completely ridiculous proposition...

12 December 2003, 07:25 AM
the anamolies i mentioned earlier about the skeleton being crushed in... this was indeed caused by the evaluate nodes settings being turned off for ik solvers and constraints. What happens is that you turn these off in order to be able to rotate joints and thereby paint weights...then you save your file and turn off the computer. When you turn it back on, your joints look all screwy which of course makes your skin act all funky as well.

if you look at evaluate nodes the ik solvers and constraints boxes are checked on, even though when you saved they were off. Strange, right? Well, they're not on even though they're checked.

Solution: hit evaluate nodes > evaluate all. Everything on your skeleton will pop back into place.

12 December 2003, 07:37 AM
Should I be weight-painting the triangulated or original quad version of my game character model?

for that matter when i go to UV map it, should i UV map the triagnulated version or the original quad?

also is it not ok to go back and alter the mesh topology AFTER it's been bound or can I still make little clean up tweaks to get it to deform better or simply be more efficient?

12 December 2003, 05:38 PM
Can I copy weights only from one specific portion of the body, such as a hand where the modeling is identical and where the weighting should be identical, from one character to another?

i don't want to transport the weights for the body for example. just the hand.

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