Sorry your browser is not supported!

You are using an outdated browser that does not support modern web technologies, in order to use this site please update to a new browser.

Browsers supported include Chrome, FireFox, Safari, Opera, Internet Explorer 10+ or Microsoft Edge.

3 Dimensional Chat / Is rigging really trial and error?

Author
Message
adr
23
Years of Service
User Offline
Joined: 21st May 2003
Location: Job Centre
Posted: 25th Jun 2006 03:42 Edited at: 25th Jun 2006 03:55
Link
I haven't attempted animating in a very long time (over a year) and today, rediscovered why. I hope that I'm misunderstanding something basic about animation - surely it can't be this difficult?

Whenever I rig my character and start moving bones around, huge creases pop out, distorting the model. I've adapted my modelling technique to include creasable sections (or slack space), but I'm actually at a loss as to how to assign the vertices. For example, when rigging a knee cap, does the entire knee go to the thigh bone, or are the knee cap vertices' assignment split between the thigh and the shin?

The worst culprits are (understandably) the shoulders and the thighs - whenever they get moved, it looks attrocious. Is there a science to this, or do people really spend hours and hours just tweaking a single vertex?

I'm currently using Pacemaker, and it seems quite cool (aside from the current lack of an undo function arrrg). Is it the case that if I bought XSI or something, would the process be any easier? I appreicate high end tools simplify processes, but I'm attempting something very simple here, so I'm not sure the problem stems from choice of tool.

[center]
But you see, I have the will of the warrior. Therefore, the battle is already over. The winner? Me!
Back to top
Profile PM Website
dark coder
23
Years of Service
User Offline
Joined: 6th Oct 2002
Location: Japan
Posted: 25th Jun 2006 08:45
Link
well to stop the polys being stretched during animation or to minimise the effect, would depend on how you model your characters alot of people model them with both arms out at 90degrees and legs parted this allows for more angular movement each way before you notice any stretching, and also makes rigging a whole lot easier, but other than that you could try mapping the stretching areas with more mapping space so they look good when at the maximum stretching angle and when at a normal pose it should still look good.

Hallowed are the ori.
Back to top
Profile PM Email
Manic
23
Years of Service
User Offline
Joined: 27th Aug 2002
Location: Completely off my face...
Posted: 25th Jun 2006 14:22
Link
its a mix of a science and luck. the best way i've found to work out vert weights is to put your finger on the part of your body that you're concentrating on rigging on your character, and then move your arm or leg. See how much each imaginary vertex on your body is effected by which bones.

sadly like most parts of modelling, it really is a case of tweaking individual verts until you go mad.

I don't have a sig, live with it.
Back to top
Profile PM Email Website
Oolite
20
Years of Service
User Offline
Joined: 28th Sep 2005
Location: Middle of the West
Posted: 25th Jun 2006 17:28
Link
regardless of how easy they try and make it, it is still trial and error, i usually assess the animations a character needs to do, then make a small animation of him moving to all the extremes of the movement he needs to do. Then add it when i'm skinning, and tweak at everytime he moves to an extreme pose, that way, its easier, but it is one of the most tedious jobs beside UV mapping.
Back to top
Profile PM Website
adr
23
Years of Service
User Offline
Joined: 21st May 2003
Location: Job Centre
Posted: 26th Jun 2006 12:43 Edited at: 26th Jun 2006 12:44
Link
@Oolite

That sounds like a good approach - do the animations first (with rough vertex assignments), then tweak the vertex assignments. It sounds obvious, but I find it impossible to get any animations done because I get distracted with all the creases and folds. So I never actually finish anything.... just a whole bunch of frustration.

I might just try that.

[center]
But you see, I have the will of the warrior. Therefore, the battle is already over. The winner? Me!
Back to top
Profile PM Website
Oolite
20
Years of Service
User Offline
Joined: 28th Sep 2005
Location: Middle of the West
Posted: 26th Jun 2006 13:33
Link
I find its easier to hide your mesh to do the animations, like you said, less distraction and it saves you tweaking half way through your animations.

Either way, it just takes patience, much like the rest of 3d to be honest.
Back to top
Profile PM Website
Manic
23
Years of Service
User Offline
Joined: 27th Aug 2002
Location: Completely off my face...
Posted: 26th Jun 2006 13:43
Link
Oolite: i really don't find UV mapping that tedious any more, especially since pelt mapping came about. infact i find it kinda theraputic, especially after worrying about meshflow for so long at the start of the model

I don't have a sig, live with it.
Back to top
Profile PM Email Website
Oolite
20
Years of Service
User Offline
Joined: 28th Sep 2005
Location: Middle of the West
Posted: 26th Jun 2006 18:32 Edited at: 26th Jun 2006 18:32
Link
Pelt was a bit of a disapointment for me, it came too late.
I stick with the normal way of doing it especially for higher poly stuff, pelt mapping is really slow with high poly models.


Although, Z-Brush does my Unwrapping for me now, plus all of my normal maps and texturing.
Heaven
Back to top
Profile PM Website
Van B
Moderator
23
Years of Service
User Offline
Joined: 8th Oct 2002
Location: Sunnyvale
Posted: 26th Jun 2006 18:41
Link
For a kneecap, well a leg in fact, I'd rig a hip, knee, and ankle bone in the obvious places, but the hip should be rigged to the waist and all the way down to the start of the knee, then the knee should be rigged down to the ankle.

If you do this, you can normalise and adjust the strength of the vertices that are shared between bones, like reduce the strength of the waist vertices attached to the hip - that way when you rotate the hip the waist vertices get rotated more smoothly than the leg, and the knee works the same.

If you just rig the closest verts, it gives real weird results, like the mesh is made from cheese or something.

What are you using to rig with incidently?, the only app I get on with for animation is characterFX.

Aegrescit medendo
Back to top
Profile PM Email
Van B
Moderator
23
Years of Service
User Offline
Joined: 8th Oct 2002
Location: Sunnyvale
Posted: 26th Jun 2006 19:34
Link
Actually, there's a good example here using CFX...

http://www.psionic.pwp.blueyonder.co.uk/tutorials/lowpoly/zbones.html

But in particular, this image shows what I mean:



I'd have grabbed the row of verts above too, and used less strength so the blend with the top part of the arm, quite a low poly example though.

Aegrescit medendo
Back to top
Profile PM Email
adr
23
Years of Service
User Offline
Joined: 21st May 2003
Location: Job Centre
Posted: 26th Jun 2006 20:35 Edited at: 26th Jun 2006 21:05
Link
Quote: "If you just rig the closest verts, it gives real weird results, like the mesh is made from cheese or something."

Well, that was what I was doing, and as you correctly predicted, getting odd results. When I mentionned the knee before, I figured that was a good example of this problem; do the vertices which describe the knee cap belong to the upper leg (femur), or the lower leg (tibia/fibula) or are they split over both bones?

Quote: "What are you using to rig with incidently?"

Pacemaker. Fantastic app, if only for the built in physics simulator. Pick a joint, configure the force, hit go and the "bullet wound to the shoulder" animation is rendered to keyframes for you

Download the demo and test it out ... there's all sorts of stuff to do with IK which I don't understand yet, but it's a perfectly able rigger/animator ... it just lacks any sort of undo, which is a shame.

[center]
But you see, I have the will of the warrior. Therefore, the battle is already over. The winner? Me!
Back to top
Profile PM Website
Van B
Moderator
23
Years of Service
User Offline
Joined: 8th Oct 2002
Location: Sunnyvale
Posted: 26th Jun 2006 21:04
Link
Well if you have vertices level with the height of the knee bone, then the row of verts above the bone, and all the way down to the ankle would be assigned to that, then the hip bone would also use the top of the kneecap, so those verts would be shared. After that it's really a case of getting the strength of each bone assignment on the shared verts - tricky but it's the best way.

I'll be sure to try that Pacemaker demo, probably gonna find that characterfx is not so great for ragdolls (Ageia and all that stuff).

Aegrescit medendo
Back to top
Profile PM Email
adr
23
Years of Service
User Offline
Joined: 21st May 2003
Location: Job Centre
Posted: 26th Jun 2006 21:07
Link
Pacemaker's interface is a little ... quirky sometimes. I'm not totally with it, but I'm sticking with it because I don't know any better

Incidentally...

The amount I've learnt recently using Wings3D is phenomenal. I've also picked up a few texturing techniques over the past 12-18 months. If I can get to a similar stage with character animation, then I'd consider putting together a few "3D Modelling for non-3D modellers" type tutorial.

[center]
But you see, I have the will of the warrior. Therefore, the battle is already over. The winner? Me!
Back to top
Profile PM Website
Back to top

Login to post a reply

Server time is: 2026-07-26 16:04:05
Your offset time is: 2026-07-26 16:04:05