Rigging Mayhem

[Spinell]

I hate rigging.

I love creating mesh and sculpting, but rigging has always been a nightmare for me and no matter what, I've never been able to perfectly rig any of my meshes.

And now that I've returned to blender, this is giving me new nightmares. Here's my latest problem:

 

Here's the technique I've been using to rig (it works for most meshes, but not this one, apperently):

1. Select the mesh, go into edit mode and select all vertices, then back to object mode

2. Shift-select the basic SL armature and CTRL+P to parent to armature with empty groups (sometimes, automatic weights works better, dunno why)

3. Select the mesh and **bleep**-select the basic SL avatar model

4. Use the bone-weight copy script

 

Not sure why this isn't working with this particular mesh. It's not too heavy (53 LI when uploaded).

If anyone has any suggestions on rigging in general, please I beg for your insight. And yes, I know I should probably get Avastar, Gaia is a freakin' genious for creating such an amazing tool, but I don't yet have enought L$ to purchase it. To make mroe L$, I need to upload more content. See my dillema? XXDD

So, tips and tricks are certainly welcomed. ;)

[Chosen Few]

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Spinell wrote:

I hate rigging.

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Don't take this the wrong way, but that's the number one problem you NEED to solve, before you even try to tackle anything specific that went wrong with this particular rig.  Hating it is always a result of not fully understanding it, and you'll never become good at it if you don't understand it.  Once you do understand it, there's really nothing about it worth hating.

The key thing to realize is that rigging is just like any other part of the 3D modeling process.  Just as with all things in the digital arts, it is 50% technical, 50% artistic, and it only becomes highly enjoyable, once you resolve to embrace it equally from both sides. 

If you see it as just one without the other, it's inevitably a horrible experience.  Without the artistry, it's tedious, and without the technical, it's nebulous.  In either of those scenarios, it's painfully frustrating.  But when you approach it properly, the experience is engaging and gratifying.

From what you've written in your post, it sounds to me like you've been over-valuing the technical, and almost completely ignoring the artistic.  So, OF COURSE you've been hating it.  You simply can't enjoy it under those circumstances.  No one could.

Now here's the good news.  You WILL find that when you accept rigging as both an artistic process and a technical procedure at the same time, it instantly becomes fun and rewarding, and the difficulties and frustrations you've been hampered by thus far will simply vanish.  Then, and only then, will you find yourself getting consistently great results.

My best advice to you right now is to let go of everything you know, or think you know, about rigging, and start over, mentally and emotionally.  I know that's easier said than done, especially if your dislike of it has been festering for a long time.  But really, it's the only way you'll be able to become effective.

Bottom line: anyone who can't bring him/herself to learn to like it for what it is just shouldn't be doing it.  If you're going to be doing it, you MUST learn to enjoy the process of it, both artistically and technically.

 

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Spinell wrote:

I've never been able to perfectly rig any of my meshes.

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Before you beat yourself up too badly for that, you may want to consider that no real-time rig will ever be perfect.  This is especially true when it comes to SL, since the platform allows so few options. 

There will always be things that cannot work flawlessly.  For example, without a cloth solver in place, or at the very least, the ability to add bones to the skeleton, there's no way to well simulate flowing or loose-fitting fabrics.  Without a dynamic system for muscle simulations or morph target animations, there's no way to make the various body parts deform realistically as they move.  The list goes on and on. 

The limitations we have to work with are extreme.  The best you can really achieve in SL at this point is a semi-passable rig.  A really good rig, let alone a perfect one, is entirely out of the question.

That said, you can, of course, attain far better results than what is shown in the picture you posted.  You're just going to have to be willing to get your hands a bit dirtier than it sounds like you have been up until now.  Read on.

 

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Spinell wrote:

 4. Use the

bone-weight copy script

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There's your main culprit, right there.  You're looking to an automated one-button action, and expecting it to act as a solution to what ultimately is an artistic problem that requires a human touch to solve.  Remember, rigging is an artistic process to be practiced and applied, not just a button to be pushed.

Copying weights is only a first step in what needs to be a multi-step journey.  You now need to finish the job with additional (basic) techniques.

Your first task, if you haven't already done it, is to develop your weight painting skills.  This is an absolute MUST.  I simply cannot stress the point enough.  Expecting to be able to rig successfully without becoming an accomplished weight painter is like expecting to be able to cook without first knowing how to boil water, or expecting to be able to read and write without first learning the alphabet.  Yes, it's that basic, and that crucial.  There's absolutely no way around it (nor should there be).

 

I'm afraid I won't be able to dive into specific how-to's for Blender, since I'm not an active Blender user (Maya is my weapon of choice).  However, I can certainly give you general pointers that apply equally to all programs. 

In most cases, you'll find that the weighting process works best when you start from the extremities, and work your way inward.  For example, start by painting a hand to be 100% weighted to the wrist joint.  You'll inevitably bleed a little onto the wrist skin area of the forearm. Just let that happen.  It's a good thing.  Now, paint over the whole forearm, additively, to weight it to the elbow joint.  You'll add elbow weight to the parts of the forearm that were already weighted to the wrist, and a little bit of that bleeding from the hand will remain.  That's exactly what you want.  If you did it right, you'll now have a perfectly functioning wrist.  If the wrist area distorts badly as the wrist bends, that's a sign that you haven't yet weighted the area strongly enough to the elbow, so just add a bit more paint.  (Those wide sleeve cuffs in your picture, by the way, should likely be weighted 100% to the elbows.)

Repeat the process, working up the chain, from wrist to elbow, from elbow to shoulder, from shoulder to spine, and you'll have a well rigged arm.  Do the same for a leg, starting at the toe, then working to the ankle, to the knee, to the hip, to the pelvis.  Finally, do the head, then the neck, then each spine joint, all the way to the pelvis.

You'll find that by working this way, from the outside in, you'll get good results, fairly quickly.   I do not recommend trying the opposite, working from the inside out, as you'll end up having to subtract weight instead of adding it, and then you lose a lot of control.  You can end up spending all day playing whack-a-mole with stray vertices that won't cooperate.  As soon as you squash one subtractively, another pops up to misbehave somewhere else.  By working from the outside in, entirely additively, you'll never encounter that kind of trouble.  A rig that might have taken you a whole day or more to do subtractively can be done additively in an hour or two, or in many cases, just a few minutes.

To put it in terms of hierarchy, it's always more effective add your way up from the bottom of the chain, than to try to subtract your way down from the top of the chain. 

If any of what I just said does not make sense to you yet, that's OK.  Consider it confirmation of what I said earlier, that you really do need to reboot your rigging experience, beginning with the very basics.  There are plenty of tutorials on the Web for weight painting in Blender, and there are lots of Blender users here on the forum, who can help you with the program specifics.

So you know, getting that dress from where it presently appears to be, to where you want it to be, constitutes only a few minutes worth of work, once you've got a mastery of the basics of weight painting.

[Devriv]

Chosen Few, although this is not quite related to Spinell's post, I just want to use this opportunity to thank you (without excluding other wonderful helpers and experts on these boards) for your exemplary replies and explanations (wherein you not only explain how, but even more importantly, also explain why) many of which I have come across and helped me during the past few weeks in my own search for help and solutions as a new Blender/3D modeling student.

[Spinell]

I would also like to thank you Chosen, you were a real help! You were inspiring and gave me a push in the right direction. I relearned the basics of weight pain and it's working much better now. I fixed the sleeves perfectly and today I'll tackle on the skirt. Almost there.

 

I was wondering if you'll andswer two questions I couldn't really find an answer for, though:

How do you paint the inside of the mesh when your brush can't really get in there, and do you need to add weights to the pelvis bone?

[Chosen Few]

Thanks for the kind words, Devriv.  Much appreciated.

[Chosen Few]

Glad to hear things are going better, Spinell.  To answer your questions:

 

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Spinell wrote:

How do you paint the inside of the mesh when your brush can't really get in there

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I'm not completely certain what you mean by "inside". 

If you mean you've got hidden polygons that won't be seen, the answer is don't paint them; just delete them.  It's never a good idea to waste resources on anything that people won't see.

If you mean the avatar is wearing more than one garment, and they're each meant to be individually removable, then paint them one at a time.  Turn off visibility on the outer ones, in order to get to the inner ones.

If you mean you were thinking of painting the backfaces, there's no need for that.

If you meant something else, please explain.

 

 

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Spinell wrote:

and do you need to add weights to the pelvis bone?

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It depends on the model, of course, but usually the answer is yes.  The pelvis is the root of the skeleton, so the things that should be weighted 100% to it are whatever areas of the skin that you want to be absolutely unmoving, not influenced by any pull from the extremities or upper body.   On a nude human model, this would generally include the tailbone area, some parts of waist, the perineum, possibly some of the lower abdomen, etc. 

On a poofy Victorian skirt like the one in your picture, you'll probably want a good portion of the upper part of it to be married to the pelvis.  In RL, that area would be held up by a bustle, and so would be quite rigid.  The lower portion would be only minimally impacted by the legs, since the fabric drapes so far from them.  Women wearing those dresses tend to appear almost to float, more than walk, across the ground.  I'd suggest, therefore, that the lower portions of the skirt be heavily weighted to the plevis, and just very lightly weighted in the front to the ankles and knees.

The effect will never be truly realistic looking, though.  In RL, the front of the skirt gets kicked as the woman takes each step.  It flies forward a bit, in response to the kick, and then falls back to its passive vertical hang afterward.  There's no way to replicate that in SL. 

Also, sitting will likely break the illusion completely, so you might want to include a second version of the skirt, modeled in a seated pose, and swap visibility between the two versions.

Once again, a perfect rig is out of the question.  The best you can do is a half decent one.

[Ferd Frederix]

You can hide surfaces that are in the way by selecting the surface and typing h. Alt h will show them. Sometimes I use H to make a larger hole, camera inside, and look around internally. I often will end up with complex inner surfaces that are hard to paint, such as between teeth, or in folds in clothing. Deleting them would be stupid, as these folds will move and become visible when the mesh flexes.

 

Take teeth as an example. Since they are part of the head, I type 'a' to get all the head selected, click m_head in the vertex group, then click Apply. Then I paint the neck, click Select , so the neck is highlighted, click the m_head group, and then Remove. I am finished with the head in seconds.

 

 

You do not need any weight paint for any bone. But if you want your avatar to tilt if an animation moves the pelvis, then you should paint the pelvis.

 

I find it best to paint a rough draft in the base pose, then pose the avatar and paint with with mix and blur to get the joints looking their best. The same Select a group to see overspray, and the subtract brush is how you remove overspray.