Short skirt rig with new collision bones

[Nirmanakaya Yalin]

So I took my skirt, already rigged for standard sizes, adjusted the shape for Ruth, downloaded the .ma skeleton, and started to rig again in Maya (2012).

And there starts my problem. I copy the avater skin weight to the skirt, then manually adjust the weights.
While the old skirt was weighted finely to hips and pelvis, the new skirt is bind to PELVIS, R_UPPER_LEG, L_UPPER_LEG, to follow the deformers.

Tested on a standard size M, in fact deforms quite nicely. The trouble starts when walking. The collision bones acts pretty weird on movements, and is very difficult to predict it in Maya. So now I'm trying to fix it manually, but looks like a long way and not very good.

Maybe is because the new collisions bones move the pivot of weights, so all skirt behave too differently?

I'm short of ideas atm...and don't understand what I'm doing wrong.

here is the old skirt (with pivot on hip) vs the new skirt (w pivot on L_UPPER_LEG)

any help is greatly appreciated :)

[Cathy Foil]

Sounds like you did everything right to me.  In SL try wearing Ruth's shape and see if you get the same result when walking.

There is a couple of things that could be happening.  One I take it you are copying the weights from the avatar LL provided that is weighted to the collision bones.  If that avatar's weights are off then your skirt weights will be off as well.  

Two your avatar mesh in SL weighted to different bones with, as you mentioned, joints that are different positions.  I am not sure but something tells me that vertices might move differently because of the offset position of the collision bones. (UPDATE: Just did a test in Maya.  I copied the weights of the female avatar mesh that was provided by LL weighted to just the collision bones.  Then detached the skin and moved the L_UPPER_LEG joint way away from the avatar even rotated it.  THen I smooth bound the mesh back to the skeleton and replaced the weights with the weights I just saved.  When I rotated the mHipLeft joint the leg bent totally the same.  So it doesn't matter that the collision bones joints are offset.) Note it does make adjusting the weights after Smooth Bind harder since Smooth Bind uses distance from the joint to determine the initial weights. 

Lastly it could simply be that because the real avatar mesh changes shape mostly by a totally different method using Morphs than Fitted Mesh which change shape by changing the scales of the collision bones.  So when you walk, the result of the difference between the two methods becomes more apparent.  The skirt vertices just don't follow exactly the relative positions of the avatar mesh as you move your avatar shape away from Ruth's shape.

Here's a link to a topic I started for a solution that goes can fix a lot of these types of issues:
http://community.secondlife.com/t5/Mesh/Custom-Sliders-for-Fitted-Mesh-a-Solution/td-p/2495979

Hope that helps and if you like the custom slider solution please comment on my post there.  We need to get LL's attention on it.
Cathy

 

[Nalates Urriah]

I'm still working my way through working with Fitted Mesh. As I understand it, the weighting you had should have been transferred to the collision bones without change for your skirt to work as before. It should have worked the same as previously but with the added ability to resize.

Allowing the modeling program to automatically assign bone weights from the collisions bones is likely to be a problem because they do NOT match the mbones. The mbones we use to animate are likely going to give a better weighting. That weighting when transferred to the collision bones, seems to work pretty well. But, the BUTT and Pecs weighting still has to be added.

The new bones currently have little weighting information. The SL Wiki files have problems and I have yet to get weighting from those files to work. In the avastar group importing the Wiki files through Blenderand into to SL was being discussed. It simply does not work. Seems there is a Collada export function problem with plain Blender.

But, even using the Avastar Collada export, which generally works, I have had problems. The avastar people are still sorting out the SL Wiki files.

I had hoped to import the SL Wiki files and verify they worked well before starting to use the weighting from them. But, there seems to be problems. Gaia Clary is working with Blender to get plain Blender's Collada export for SL/OpenSim fixed. Gaia had figured out how to fix some of the problems with the SL Wiki files, but not all. I haven't taken time to get things sorted out.

Suggesting you compile a new viewer with additional controls doesn't really solve your or my immediate problems. The blog.machinimatrix.org tutorial videos (also in youtube - search on gaia Clary) show how we are handling weighting transfers in Blender. I suspect yuo could do something similar in Maya. The Blender copy weights to Empties moves weighting to a new parent without changing the weighting. I am guessing there is something similar in Maya.

 

[Tajomaru]

After uploading the skirt rigged to the collision bones, it will be fitted to the shape sliders by SL. The skirts may look the same in Maya, but Maya doesn't do any fitting. 

[Nirmanakaya Yalin]

Thanks for the replies:)
@ Cathy
Yes I saw the amazing work u did, but that will need an adjustment made to the viewer, and after all I can see a bit the deformation just rotating the joints directly in Maya. And you're right, the problem lays in the distance of the vertices from the joint, that mess up weights in movement.

@ Nalates

I agree with you, this avatar file is poorly rigged, and still give errors in Maya. Just try to go to bind pose with the avatar body selected. Pinches all the bones on the back. I have to do a research on how to do the weights transfer in Maya, still I don't find an exhaustive video on Blender, guess that Gaia Clary is still working on fixing the SL rig files.

I'm not an animator technician, but I don't understand why we can't keep rigging to the mbones ( that are the ones that determines movement anyway) and simply manually add correct weights to collision bones. Even if, as is now, and as I see, collision bones interfere with movements, and in my opinion should not. Look for example at the BELLY. Is parented with mTorso, but its influence goes down till pelvis. So if I add the BELLY influence on that skirt, it will move with torso and break the belt line that moves with pelvis.

So is better to wait for a fix of the SL wiki files? Will they be aware of the problems?Imo in this way rigging is completely broken.

What do you think?

 

[Medhue Simoni]

I'd chalk it up to how Fitted Mesh works. My guess is that the collision bone axis is causing this behavior. I rigged a full body suit, and when the avatar follows the mouse, you can see the body and the mesh are moving independently. I'll likely do a video about my final reactions to Fitted Mesh. It's not as bad as I intially thought, but IMHO, it isn't good at all. Even at this point, it a barely workable hack.

[Cathy Foil]

@ Nirmanakaya

I have a few suggestions.  In Maya when you use Copy Weights tool before you copy the weights open up the Copy Weights Options window and turn off the copy Smooth Bind option and see if that gives you a better result.  You might also want to just export out of Maya the avatar mesh itself that LL rigged and weighted to the Collision Bones as a DAE file and then upload it to SL and wear it.  Then you can see just how well the avatar shape follows the real avatar's shape.

Another suggestion would be to Smooth Bind to the Normal skeleton bones and not the Collision Bones first.  Then adjust the weights to your liking.  Then save the weights to a file.  Open up the saved weights file in a word processor and replace the normal skeleton's "m" names with the Collision Bones names and save it.  Then replace the weights of your mesh with the new weights you just created.  This should work for the Arms, Legs, Neck and Head because for those areas for each "m" or normal bone there is a corresponding Collision Bone.  So mHipLeft  = L_UPPER_LEG and so on.  Problem is in the pelvis area and chest area.  There are more Collision Bones than Normal Bones but at least is should be a start.

Now I am on an older version of Maya.  I am on Maya 8.0.  Saving the weights is limited so I use a free Plug-in named Comet to do this with.  A newer plug-in I just found is Dora.  It is compatible with more Maya versions than Comet.  Dora is compatible from Maya 7 through Maya 2012 though I don't know why it would be compatible with 2013 or 2014.  Maybe the creator just hasn't updated the listing on Creative Crash.  Anyway Dora has a built in bone name changer which is probably easier to use than editing in a world processor.  Here's the link to it.

http://www.creativecrash.com/maya/script/dora-skinweight-import-export

Hope the helps.
Cathy

[krasnirex]

The (.ma) files are not working for some Maya users. The most evident indication are those pinches that happen when you set the rigs back to bind pose. The best approach would be to use the (.fbx) files included instead of the (.ma) ones. I have been using those, and they are much less problematic.

[Nalates Urriah]

Broken... I don't think it is broken. I do think the SL Wiki files are messed up. That makes what we do a mess.

There is a Maya problem that extends into what Blender does in the Collada export. The SL Avatar was apparently orignally made using Maya and a Poser avatar. Something about how Maya and SL scale things, which I didn't understand. But, I have more information and links to the discussion here: http://blog.nalates.net/2014/02/19/more-fitted-mesh-news/

Until I can get a Blender 2.7 release I am blocked from testing the SL Wiki files and farther than I have.

I think the weighting we have is incomplete. I uploaded the Collada file from the SL Wiki. It works pretty well. But, it is NOT an exact duplicate of the SL Avatar we see in the viewer. I would love to be able to extract that avatar and see how it compares to what we have been given.

Once I have a Blender 2.7 RC I plan to compare the Collada files from Avastar, the fitted-270 file, and the SL Wiki Collada file to see what the differences are.

[FadeArcade]

This is certainly frustrating and looking more and more bleak everyday.

I could spend all day trying to weight my mesh to get this to work "semi" ok with the avatar files as they are now, but in the end - all that time is just a waste because I'm not going to settle for anything less then perfect. I'd much rather wait until LL gets out official files that allow me to easily copy the weights from the avatar and let me tweak with minimal effort like the avatar files before this. 

The work to success ratio for the current files is way off and even if you were able to get an alright fit with the fitted mesh, I could have already worked on and completed a completely new mesh from start to finish. 

The biggest WTF of them all is how are you supposed to test the scaling effect from within your chosen 3d program? You really think we have the time to spend hours weighting something that look fine in the modeling program but acts completely different and unexpected when seen in-game?

I scale the belly collision bone and my mesh explodes width wise instead of pushing the belly out like it does in-game. Does the belly scaling in game also scale up other bones along with it to give it that effect? If it does, you need to tell us exactly how much and which bones are effected by the belly slider. I don't have time to guess-timate your rig with this sort of disregarded information we need as creators. 

We need completely perfect avatar rigs, that when you scale up the collision bones - the mesh and avatar scale exactly as they do in-game. Until then, what is the point. Really.

You might brush by these sort of problems if you have a baggy shirt that has a foot inbetween you and your avatar - but 99% of my mesh is skin tight (you scale the hips, and the model explodes 5 inches away from the model. pff ) - and I'm certainly not going to spend longer then an hour trying to rig. 

The supplied files don't even have handle weights on the avatar. What the hell Linden Labs. Srsly.