Really bizarre rig/spline behavior

[edlundart]

As I was smartskinning my model the other night, everything was looking good with the shoulders and I decided to move on to the legs. In an action, I then discovered something very odd and very frustrating. If I move the left leg up a lot, the geometry on the character’s chest and right arm gets distorted. Basically, several select CPs move slightly as though they were connected to the leg bones. However, this is not at all the case! I see no logical reason why some CPs in the arm would move around when I lift up a leg, since no CPs in the arm are assigned to anything but arm bones!

 

Tonight I am going back through my 250 saved files to see how far back in my project this problem occurred. I don’t know if it’s somehow a result of smartskinning or if it was a problem even before I started working on the smartskin. The problem only reveals itself when I move the leg somewhat drastically high up.

 

I’m also wondering if maybe I can fix it by deleting the CPs in question and then re-creating the geometry in those areas.

 

Has anyone seen a similar problem, and does anyone have any advice about how to avoid this? As it stands right now, I can’t see how this is anything other than a bizarre bug.

 

I'll post updates if and when I figure this out.

[itsjustme]

Have you put the character into an Action, moved the legs until the wrong CP's move, right clicked on those CP's and checked the CP Weighting?

[edlundart]

I just tried that, and the CP weighting looks normal (100% to the bone that is logical).

Going to try to rebuild the arm over the next couple of hours and see what happens.

[KenH]

If you can post the model (or part of it) do so. It could be something solvable.

 

I doubt it's in the mesh....but some sort of boning issue.

[edlundart]

Here is the model, minus her head... it's not a totally finished model, I have some tweaking to do, but I started rigging in test files to see how it would work.

In an action, grab her left leg (the one you see on the right in the front view) and translate it up as high as the hip bone. You will see distortions in the chest as well as her right arm. Any ideas?

 

woman_forum_review.mdl

[edlundart]

Not sure if that worked. Here is a zip file.

edlundart_model.zip

[mtpeak2]

The problem is in the left thigh smartskin. Delete the smartskin relationship from the relationship folder and redo the smartskin.

[edlundart]

Thanks, I'll give that a shot, although I am 90% done with the remodeled arms, and prefer them to the old ones anyway. So I need to redo the smart skin no matter what. But thanks a lot for looking into it, I'll definitely try what you said to see the problem isolated. But I'm curious... I've seen people asking how they can make several smart skins per bone. Should I be doing that? What I have been doing is focus on the bicep bone, and tweak the geometry for one extreme position, then another, then another, etc. Would it work, and would it be better, to make one smart skin per extreme position? Am I asking for trouble by having one smart skin account for all possible positions of a bone?

 

As always, thanks for all your help.

[mtpeak2]

Also delete the left foot smartskin, arm problem.

[mtpeak2]

You're better off weighting cps first, before you smartskin. Smartskin only when weighting doesn't do the job.

[edlundart]

Yup, I've picked up that lesson. I still don't know what I did with the smart skins to cause this weirdness though, but when I do this again I will attempt to be even more careful.

[mtpeak2]

Found another bad smartskin, the pelvis, I'm sure there's more.

[edlundart]

Hmm... I think a theory is developing here... I did not yet create a smart skin for the pelvis, nor for the legs. But I transfered the skeleton and relationships from the Thom model. Is it possible I also transfered smart skins for Thom and that I've been altering those instead of making new ones that would be unique to my model?

[mtpeak2]

Bingo. If the cp's in the thom model have the same id # as cp's in your model, the smartskin will effect your model.

[edlundart]

Aaaah....

how can I delete all smart skins to make sure I'm making new ones that are not affected by anything old from Thom? Do I have to go through each and every bone in the PWS? I'd rather not lose the skeleton...

[mtpeak2]

Open the relationship folder, you will see bones (smartskin) and user properties relationships, delete the bones to remove all smartskin or open the bones to see all the bone that have smartskin and delete the ones you don't want.

[edlundart]

Thanks for taking the time to sort this out with me, I really appreciate it. I'm sorry to possibly exhaust your patience, but I'm not 100% clear on your last instructions.

In PWS, I open the Relationships folder and I then see a bones folder. Opening the bones folder reveals the list of all bones in the rig. The 1st one is Back. If I open that one I get Transform relationships and inside that Rotate relationships. In rotate relationships there is a smart skin item. Are you saying I should delete that, and then go through every bone in the list and do the same? If so, that's not a big deal, but what about "user properties relationships"? Do I have to do anything in there?

 

Thanks again for your help and patience.

[itsjustme]

Thanks for taking the time to sort this out with me, I really appreciate it. I'm sorry to possibly exhaust your patience, but I'm not 100% clear on your last instructions.

In PWS, I open the Relationships folder and I then see a bones folder. Opening the bones folder reveals the list of all bones in the rig. The 1st one is Back. If I open that one I get Transform relationships and inside that Rotate relationships. In rotate relationships there is a smart skin item. Are you saying I should delete that, and then go through every bone in the list and do the same? If so, that's not a big deal, but what about "user properties relationships"? Do I have to do anything in there?

 

Thanks again for your help and patience.

 

You won't need to dig into the folders, you can just delete the references to the bones (which includes the underlying folders) to get rid of the Smartskins. Leave the "User Properties Relationships", those are your poses.

 

Hope that helps.

[edlundart]

Oh -- but then won't I lose other important stuff? Like how bones are anchored together and so on?

[itsjustme]

If you delete everything in the "Relationships/Bones" folder, you will only be deleting the Smartskins...if you delete everything in the "Bones" folder just below the model's name, you'll delete actual bones.

 

Hope that helps.

[edlundart]

I see. Thanks so much David. I'll give this a go.