SHOULDER RIG NATURAL VS STANDARD

[UNGLAUBLICHUSA]

<_ i currently have my character rigged in what would call the standard way. a shoulder then humerus radius one read tutorial by mark snoswell which addresses software how to replicate correct alignments rotations of joints.>

 

He suggests an intermediate bone. I am including 2 screen captures, one of my rig 'standard' and one with the Snoswell method overlayed for reference.

 

I am looking for feedback on what you think of this concept and AM ways to do it.

 

EDIT:

 

I also added a version I am trying to replicate the Snoswell way in AM.

[robcat2075]

can you show us each version moving?

[3DArtZ]

what is which here?

 

Mike Fitz

www.3dartz.com

[zandoriastudios]

In your examples, your A:M bones are not aligned with where the actual skeletal bones would be. Putting the A:M bones where the real skeletal bones would be is the best placement. Intermediate bones are used to help deform the mesh naturally (since the skins surface is offset by tissue).

 

3DArtz has a tutorial on using intermediate bones to help blend the joints. Since the introduction of CP Weighting, the need to use a lot of intermediate bones has been reduced--with the exception of "twist". I find that it is usually necessary to use some intermediate bones aligned with the humerous to spread the twist away from the joint.

 

I did a Siggraph demo on this in 2005, if you have that set. You can also get this 2 hour video from my online store:

[UNGLAUBLICHUSA]

what is which here?

 

They are in order

 

Standard Method

 

Snoswell method

 

Possible solution

 

can you show us each version moving?

 

Haven't done any smart skins or fan bones yet - motion any way is horrible.

[Kamikaze]

William ,

 

would you happen to be thinking of making a downloadable version of your tutorial, for those who have high spped internet....doesn't even have to be at a discount rate either, as far as I'm concerned...

 

Mike

[MMZ_TimeLord]

In my limited experience wtih rigging, the only points that really make a difference on arm/shoulder/leg bones is the 'start position' or pivot of the bone. Where the 'end position' is really only makes a difference to the user.

 

The computer doesn't care where the end position of the clavical ends up, because the CPs associated with that bone will pivot on the bone pivot regardless.

 

So if you start the clavical where the clavical starts in a real human and the humerus starts where the humerus starts in a real human, then your shoulder should pivot properly.

 

Remembering William's comment that the problem with shoulders has not been the bones so much as the simulation of the skin sliding over the tissue surrounding those bones.

 

Also, of issue with my rigs in the past is the simulation of a realistic shoulder blade or scapula. I'm still persuing a solution to that problem... still not happy with the ones I've found.

 

Hope that helps.

[ypoissant]

To reiterate what William and Jody wrote, the most important issue is the proper placement of the bone rotation bases (or start position). They should be positioned at the pivot position of the real bones to ensure correct movements. Right now, the arm (humerus) bone bases are not located correctly in any of the 3 examples that you provide..

[UNGLAUBLICHUSA]

<_ yes will and yves you are correct in that they not where the actual skeleton would be i knew it when did them. was this quandary because have seen sooooooo many different ways people rig all of rigs am models. them bones high up shown or some even protrude outside mesh but posed look fan-damn-tastic.>

 

I am trying to improve my rigging skills and am looking at the squetch rig as a possible stepping stone. I just need to find out if the bugs have been worked out yet. I am posting my progress in another thread devoted to my Adventure Lass character. I came up with a way of improvising the deformation during the rotation of the tibia and fibia and the subsequent movement of the patella.

 

ADVENTURE LASS THREAD

[3DArtZ]

Well, keep in mind that sometimes it's not how the bones are placed alone....

If the mesh bends in a desirable fashion and looks right to the eye, then that's better than

getting the actual anatomy of the bones correct.

 

The shoulder is certianly a tricky joint and I don't believe that looking a real shoulder joint alone will

help make good shouldes.

You have to understand how the skin twists and bends over the joint.

 

for example, even though you can get your real hand/elbow to twist -90 to + 90 degrees, the skin barely twists over the shoulder joint, rather the bones slide inside. So you don't want to recreate the bones rotations, but you want to recreate the skin effect.

 

Know what I'm saying?

[UNGLAUBLICHUSA]

Exactly what is going through my mind when I am in a rig. Thats why I considered the bones at the top of the shoulder (not my idea) close to a standard because there is little skin deformation at that point.

 

Thank GOD that in AM you don't have to go the Maya or 3D Sudio way where you have to mimic every tendon, muscle, sinew, vein and fatty tissue underneath the mesh to get realistic deformations! Not me per se, I currently suck the fat ladys ass at rigging - but you know what I mean.

 

I am going for what happens on the outside - that is the rigging magic I am looking for. Maybe I need to tell the wife I want your rigging CD for Christmas...I just don't know how long I can bear to wait on getting my character to LIVE!

 

Thanks,