View Full Version : sorry but bones will be the end of me


wereuare
09 September 2003, 07:50 AM
im sorry for this thread but i need some serious help. I cannot get bones down right. ive read like 5 tutorials but i still cant get it. can someone give me a link to a video or something where someone describes it.

Robsi
09 September 2003, 09:22 AM
Hi,

try this Character Rigging (http://www.newtek.com/products/lightwave/contests/dec-02/winners/tutorials/layout/Chris_Olsen/index.html)

And Froggyplat Rigging (http://www.3d-palace.com/modules.php?name=Videos&pid=3), this one is really cool, a few hours video tutorials all about rigging. You have to register before download, but its free.

good luck, Robert

scotttygett
09 September 2003, 09:23 AM
www.joejustice.org

There is a skelegon rig in there that you can drag/stretch the LW inventory metanurb torso to fit. Find the "convert skelegons" button, and you should be able to get some fair results.

Joe goes into a lot of detail, which you may not be ready for. Just play first. 1 in 10 jobs is rigging. Apparently some guys really do get work at Pixar with animated box(es) shapes.

Stuff like rigging eyes can be found at newtek.com, but try the CGTalk Search function for a list of tutorials and the better courseware from gurus like Todd Grimes and Splinegod.

At presetcentral.com. you'll find a BVH Scene that shows non-bones animation, as well as some great modelling and texturing.

Facial Deluxe
09 September 2003, 09:40 AM
Tell us where is your problem happening ?

Skelegons ?
Bones ?
IK ?

wozzyke
09 September 2003, 11:05 AM
well cool topic as I'm trying to learn the rigging and animating too, and nothing is working as I wich it would.

I followed some tutorials on IK for the legs but my character allways starts acting like a uncontroleable puppin when you test the IK (legs in neck and stuff)

wozz

webfox
09 September 2003, 11:44 AM
If you could explain what kind of projects you've tried already and what settings you've used.... maybe even a zipped file that shows what's not working for you (without your mesh if you've created your own)... it's hard to see where things are going wrong for you.

I would recommend just to start by trying to apply bones to an extremely simple object for a start... say a tube with enough polys at the joint to make it bend at a simple elbow or knee.

Have patience and experiment with small things first so that you gain an understanding of what each little thing does first. It's not intuitive, even with a tutorial, to rig a complex character on your first try.

I can say, without a doubt though, that Froggyplats tutorials can get you going very well toward creating a very usable character. Don't miss them!

Good luck and keep us posted.

wereuare
09 September 2003, 07:11 PM
well my major problem is i cant get there to be a "main" bone that moves all the other bones and object. i also cant get the arms or legs to bend. do i need to add points at the joint??? and i dont get the skelegons either. if i add them in modeler can i switch them to bones in layout. and also how do i set limitations on each bone. those are my major problems. im gonna try to use soem of the tutorials you all gave me though thanks and if you can help more please do so.

Finkster
09 September 2003, 07:48 PM
Bones can be pretty confusing when you start out. But definitely give the froggplant tutorials a go. It takes a bit of dedication to follow along with all the videos, but his step-by-step instructions are really clear and you'll know what you're doing in no time.

Sycada
09 September 2003, 09:38 AM
Ah this is exactly the subject I'm having trouble with at the moment.
I'm trying to get the arms to raise above the head properly using IK. Every time I lift the arm goal up to shoulder height and beyond the elbows raise too and the hand ends up pointing outwards once the goal is raised right up. Anyone have a good solution to fixng this or do I have to use keyframes?

Thanks

Facial Deluxe
09 September 2003, 01:06 PM
Originally posted by wereuare
well my major problem is i cant get there to be a "main" bone that moves all the other bones and object. i also cant get the arms or legs to bend. do i need to add points at the joint??? and i dont get the skelegons either. if i add them in modeler can i switch them to bones in layout. and also how do i set limitations on each bone. those are my major problems. im gonna try to use soem of the tutorials you all gave me though thanks and if you can help more please do so.
Well, usually you draw skelegons in Modeler, and then convert them in Layout using Add/bones/Convert Skelegons.

Your "main" bones problem seems to be related to a Parent / Children hyerarchy things. Would be a bit long to explain, though it's detailled in the manual.

Yes, every joint should include more subdivs to allow the bending.

At this point, you should post a pic, and really look at some tuts.

Here's a good one for Skelegon Drawing :
http://www.simplylightwave.com/movie_pages/tutorial.mhtml?tut_id=508

Facial Deluxe
09 September 2003, 01:16 PM
Originally posted by Sycada
Ah this is exactly the subject I'm having trouble with at the moment.
I'm trying to get the arms to raise above the head properly using IK. Every time I lift the arm goal up to shoulder height and beyond the elbows raise too and the hand ends up pointing outwards once the goal is raised right up. Anyone have a good solution to fixng this or do I have to use keyframes?

Thanks

The shoulder is a hard area. Keep in mind that when rising your arm Up above the head, your colar bone moves also.
This means, you have to create the colar bone.
Also, When trying to simulate the shoulder area, I use 2 bones in the shoulder, to make it bend softly, so that it's no too squashed whe rising.
The other things I do is that my colar bone and my 2 tiny shoulder bones are Goaling the "Null Hand Goal" but with high Pitch shiftnes values ( that make them "resist" to goaling ).
As you can see these are for IK arms solutions, very personnal, and might not be the best way to do it (I don't know what's the best way..).
I would also add that IK chains are working well with 2 bones chain, that means you have to split them using "Unaffected by IK of descendant ".

wereuare
09 September 2003, 06:03 PM
i think i get the jist of it now after watchin a few of the tut. you guys gave me (much thanks:beer: ) but now im having problems with the arm geting small at the joint when i bend it 90' . can i fix that in modeler.

Facial Deluxe
09 September 2003, 07:26 PM
in bone properties, you have a "joint compensation" %, this might help a bit.
Other solution exist like adding extra bone in between (that you could scale when bending).
Or a far more elegant solution would be Smartskin :
http://www.animationsnippets.com/plugins/smartskin/index.html

SplineGod
09 September 2003, 08:38 PM
Originally posted by Sycada
Ah this is exactly the subject I'm having trouble with at the moment.
I'm trying to get the arms to raise above the head properly using IK. Every time I lift the arm goal up to shoulder height and beyond the elbows raise too and the hand ends up pointing outwards once the goal is raised right up. Anyone have a good solution to fixng this or do I have to use keyframes?

Thanks
You can probably animate faster by using a bit of FK there instead of spending hours to try and get IK to do what you think it should do. There are just too many things a shoulder can do that you cannot do with IK.
Its best to think of IK as a quick way to get you into the ball park. You still need to rely on FK to do things.
As facial mentioned, to get good shoulder deformations you need to remember that the deltoid muscles will left the arm to about parallel with the ground. After that the whole shoulder girdle (scapula and collarbone) kick in to assist.
You would need to set rotational limits on your upperarm bone so that it doesnt rotate past the parallel to the ground point and also have the collar bone rigged so that it doesnt start rotating until the upperarm bone reaches that parallel point.
You would also need to worry about joint stiffness so that some joints bend before other joints etc etc.
You would also probably need to throw in some expressions to do other things and IMO its just not worth it. By the time you had something setup and working semi reliably another animator would already be done. :)
I think the best thing to shoot for with a rig is poseability and stability instead of automation.
Use IK to get the rough animation blocked out and then fine tune it using FK. I usually tend to avoid IK on the upper body in general unless hands need to lock to something like a surface of some kind. This is a general rule of thumb for me and it really depends on the situation.
I also tend to use small bones to keep my joint volume rather then use endomorphs. I can see the results immediately and I can adjust it directly. :)

Facial Deluxe
09 September 2003, 07:54 AM
SplineGod, did you try Smartskin ?
I only tried the tutorial sample, and the combination of "Rotate Skelegon" + "Smartskin" seems very efficient.
Was wondering what's your opinion.

Sycada
09 September 2003, 10:46 AM
Thankyou for all of the helpful info. I've been doing this for a little while now but there's still so much to learn so this is all gold to me :applause:
I did wonder whether FK would be the better choice for the upper body and the tutorial rig I tried left me with the same problem with the arms that I had before.
I guess that getting the hand to twist so that the palm faces inwards when the arm is risen would be more to do with a smooth mesh and gradual bone banking throughout the arm than an ik rig right?
Thanks again and if I'm allowed to post what I get done (dunno if the people I'm working with will allow me to) then I'll try to show you guys. This is the most helpful forum I've ever visited :beer:

modernhorse
09 September 2003, 02:45 PM
After reading this thread (because it pertains to my situation exactly) I tried to register to get the vids but no go. And I can't see anywhere on the site 3d-Palace to report my problem to.

Does anyone know the administrator(s) there?
Thanks.

scotttygett
09 September 2003, 10:41 PM
Lifting arms above the head is supposed to be one of the "acid tests" of rigging, is it not? That, and crossing the arms over the chest, I think.

By the way, use "world coordinate" in Layout.

The other day I posted a suggestion to do a bouncing ball after the Preston Blair style, and then realized I hadn't gotten a result I was happy with yet?! I had to use effectors to get close to the effect I was after.

SplineGod
09 September 2003, 02:41 AM
Actually a more acidic test would be to have the character be able to touch the top of its head and touch the opposite shoulder with little distortion. :)

kretin
09 September 2003, 03:05 AM
Originally posted by SplineGod
You can probably animate faster by using a bit of FK there instead of spending hours to try and get IK to do what you think it should do. There are just too many things a shoulder can do that you cannot do with IK.
<snip>
You would also probably need to throw in some expressions to do other things and IMO its just not worth it. By the time you had something setup and working semi reliably another animator would already be done. :)

Actually, implementing IK for the arms takes about 2 minutes, and animating is significantly faster, only having 2 major controls and one minor control for IK instead of 4-6 bones to rotate...

I certainly haven't found anything that FK arms can do that IK arms can't... but I can't say the opposite... How do you constrain the hands to an object/place with FK? a heap of work, keys on every frame, and still a chance of wobbliness. With IK it's there, done for you, no work at all :)

SplineGod
09 September 2003, 03:26 AM
Hey Jonny, :)
Implementing most IK only takes a minute or two but can take longer depending on what the IK chain has to do.
Thats why I said "I usually tend to avoid IK on the upper body in general unless hands need to lock to something like a surface of some kind. This is a general rule of thumb for me and it really depends on the situation."
There are situations where IK is overkill especially if the character just has to do things where the hands dont need to be locked onto a surface.
If you have IK and want the arms to just follow the torso then one has to get into a whole parenting or dynamic parenting thing with the goals.
IK is or can be great for quickly blocking out movements. Where its not so good is for doing overlapping motions which by start at the root of the heirarchy and propogate out to the extremities. Thats because IK is inverse kinematics. Can this be done with an IK setup? Maybe but using a setup that will not be obvious or intuitive to most people.
A character jumping off a roof is another example. The feet hit first and stop, then the knees bend, then the hips, spine, shoulders, neck and head. The force is applied via FK and propogated out from the root thru the children.
This sort of fine tuning is not what IK is best at. Joint stiffness can be adjusted to try and replicate some of the effect but again theres a lot of trial and error involved.
I totally agree about the speed of IK setup and being quick to block out movement. I find that many times its not work screwing with trying to get chains to do complicated things like collarbones/shoulder areas.
And again, this is generalizing because theres always exceptions. :)

kretin
09 September 2003, 04:00 AM
Hey Larry :)

I prefer IK on arms mainly for the ease of control. I only have to translate a single null to get the basic motion down. Because IK arms are so easy to control, I actually consider FK arms to be overkill in most situations :P

I parent the hand goals to the torso as a default, so they do move with the body. Usually hand goal parenting can be decided/changed on a shot by shot basis, either parented to the body, or the character master null, or another item, just a quick reparent in Scene Editor or Motions Panel.

In cases where the arms/hands need to follow the body for part of a shot, and another item for another part of the shot, it's very easy to setup dynamic parenting with "Parenter", literally seconds work.

Overlapping motions is easy with IK, because the joints bend depending on where the goal null is, so having joints bend at different times is just a matter of positioning the goal at the right places at the right times. This may take a little practice but it's really quite simple. There's no special/complex setup required at all.

In your example of jumping off a roof, well is a perfect example of where using IK driven legs is most useful. All you need to do is to place the foot nulls on the ground when the feet hit the ground, and then leave them there, letting the body motion do the rest.

Joint stiffness is rarely required for IK arms and legs, but can be useful for things like tails, so the bones closer to the body rotate less than further away.

Fine tuning IK based animation is just like fine tuning FK animation, it's always needed, and if anything easier to do with IK. The main fine tuning necessary for IK animation is making sure the goal moves in nice arcs, usually just a matter of creating a single key inbetween extremes.

The collarbone/shoulder area is tricky to setup no matter what animation method you use for it. In my experience, it's the weights and bone placement that is most important for nice shoulder/armpit deformation. Once you've got that part right, animating it is a piece of cake whether you prefer IK or FK control methods.

SplineGod
09 September 2003, 04:40 AM
Believe it or not Ive run into some longtime animators who dont feel that good character animation can only be achieved with just IK. ive even spoken to some who hate IK 99% of the time (Im not one of them BTW). :)

I think most people Ive run into do prefer IK almost all the time for the lower body and many didnt prefer it for the upperbody.
When characters limbs need to stick to things IK is a must IMO.
Im many instances it boils down to the method a particular animaor prefers and if youre rigging for yourself or someone else.

My worst nightmare was rigging for 80 or so animators on Max Steel or Dan Dare. Each had very different ideas of what a good rig was and there were lots of different experience levels.

As you mentioned that some types of movement are possible with IK and I agree. The key is, as you mentioned is "the little practice part." :) I can do that but rigging for others usually means that you shoot for the least common denominator.

I agree about dynamic parenting. I use it, it works but again but these are things not obvious to beginners.

In production I was forced to create multiple rigs for the same character depending on what sorts of things the character needed to do and how experienced an animator was. I would usually create a more "universal" rig and then add or remove controls from there.

The other aspect is that youve probably been doing this for awhile and I know I have. Im very comfortable with rigging but I think others who are learning should stick with very simple rigs.

Thinks l like overlapping motions in the arms I can sometimes do much faster in the graph editor by sliding the timing a bit rather then playing with IK goals to try and get each part to break just so. Ive sat there and tried to show some of the animators at FI how to use IK goals that way but many just couldnt figure out how and just wanted to use FK. :shrug:
Ideally for me is something like a newer IK system which can switch between FK and IK or blend both.

Right now Im answering this from the perspective of someone trying to get a handle on the basics. :)

kretin
09 September 2003, 05:34 AM
Good points Larry. I agree, when starting out you should get a handle on FK before moving on to IK.

I guess alot of this stuff isn't obvious to beginners, which is one reason I mention it, to make them aware of the possibilities.

Hehe, someone should write a book about all this stuff... oh wait, I am :applause:

Certainly an easily blendable FK/IK system is the way to go...

I also disagree a little about rigging for the lowest common denominator. Maybe it's my stubborness coming out, but when I'm in that situation I prefer to make sure all the animators are at the same level, at least in terms of being able to manipulate a rig... rigging for lowest common denominator would prolly mean including auto pelvis centering "cringe" :surprised

wereuare
09 September 2003, 06:48 AM
can either of you explain to me what ik and fk are along with character rigging. Or if u just give me a little link to a tutorial or something i would very much appreciate it. Also how easy are they to learn. Thanks a bundle:thumbsup:

sorry if im asking for to much :drool: but all the links ive got from this thread have helped me go from:surprised to:buttrock:

SplineGod
09 September 2003, 07:03 AM
Rigging is the process of setting up something so that it can be animated. This can be a character, car, airplane or anything.
FK - Forward Kinematics, Fancy way of describing a natural heirachy of objects and how they behave. In this case lets say the bones in an arm. They start at the shoulder, then the upperarm, the forearm, wrist, finger bones etc. all the way to th end. If you bend the upperarm the bones that are its "children also move (forearm, wrist etc) but its parent (the shoulder) does not. If you bend the forearm, the wrist, hands, fingers etc all move but not the upperarm and so on. This is how a stop motion animator does his job. Its typically slow and tedius but you have absolute control over every bone at anytime.
IK - Inverse Kinematic, Yet another fancy term that is the opposite of FK. You pull an extremity like a finger and the wrist, forearm, upperarm etc are also pulled and effected but stay linked in a parent/child heirarchy just as in FK. A Muppet or Marionette would be an example of something animated in that way.
An IK "chain" consists of an "anchor"(the first bone in the chain) and an "effector"(last bone in the chain). Think of the effector as the place where the little metal rod on the puppet would screw into. You would also typically have what are galled "Goals". The goal object would be like the rod screwed into the muppets wrist or the string connected to the hand on the Marionette. This is typically a faster way to animate but has less control then FK.

There are some tutorials out there. I dont know off hand where but others will be happy to point them out. I also have some a course and tutorial CDs that cover that topic
HERE (http://www.3dtrainingonline.com) :)

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