Extra Bones before Rigging

[higginsdj]

OK,

 

So I am down to step 5/8 adding new bones/smartskin using TSM2. I need references/advice for:

 

1. Breast movement (suitable for spring system?)

2. Shoulder (Smartskin or Bones? - examples)

3. Hips (Smartskin or Bones? - examples)

 

This will be to set up my female characters:

 

 

Cheers

[luckbat]

I'm sure every animator has a different method for rigging, but here's mine:

 

1. Get the joint as close as you can to ideal using optimal spline and bone placements.

 

2. If it's not good enough, add CP weighting to iron out any weird bulges.

 

3. If that's still not enough, try adding fan bones to improve the deformations

 

4. If even that's not enough, start Smartskinning the problem areas.

 

Don't underestimate step 1! There's no reason to go crazy with fan bones and Smartskins to fix a problem that ultimately stems from less-than-ideal bone positioning. I have a working shoulder joint that uses only weighted CPs to bend properly--no Smartskin or fan bones at all.

 

There's nothing wrong with building everything in Smartskin, if you prefer--it's just that, if you decide to make even minor changes to the geometry later or, you'll probably need to completely redo it. So try to get your joint 90% of the way there just with regular CPs and bones, if at all possible. Your model will behave more predictably and be easier to work with.

 

Also, Kricket has an elaborate breast rig tutorial here:

http://demented3d.com/tutorial/lagconstraints/chest.html

[higginsdj]

Thanks Mike but knowing exactly where to position the bones is half the trouble. See my current positioning.

 

Good/Bad positioning? Any and all advice welcome. Just in case you are wondering - I have never rigged a model before

 

Thanks for the link too.

 

Cheers

[luckbat]

Well, rigging is something you just hafta learn by doing, like so much else in animation. But here are some tips I've picked up...

 

1. For a realistically proportioned human figure, each bone's pivot point should be at approximately the same spot where it would actually be in a real skeleton. (Not that our models need 33 spine bones, obviously, but you see what I'm getting at.) For example, a humerus bone is not a straight line--it's got this ball-shaped part stuck onto one corner, which is where the pivot actually is. Right, so? Well, this means that your model's shoulder pivot should actually be closer to a point directly above the armpit. On your model it's way outside the torso area, so when she brings her arms to her sides she'll look like a football player.

 

2. So how can you tell how well your rig is working? Simple. Open up an action window, IK-lock all the bones connected to the one you're working on, and then grab the main bone and swing it around. If it doesn't look right, go back to your bones window and move the pivot around. Move it up, down, left, right. Make the bone longer or shorter. Then go back to the action window, hit Spacebar to refresh if necessary, and see if it looks better. Eventually you'll find a spot where the joint seems to be working well. Save your progress and move on to the next bone. I know it sounds tedious, but the more you do it, the better developed your sense of rigging will get.

 

3. As always, techniques differ, but in general most Hashers agree that every joint needs three rings around it. One above the joint, one below, and one exactly at the joint pivot. This middle ring will be the one that you deal with in Smartskinning or fan-boning later on.

 

There are other subtleties, but that should be enough to get you going. Here are a couple of comments on your particular model:

 

* Good news! You can take out a bunch of those bones you've got in there. You've got four apiece in your arms and legs right now. Just like with a human body, you only need to start a new bone where the model needs to bend. So, for example, your legs need one thigh bone and one shin bone, and that's it. Simple!

 

* A woman's hips are generally wider than her ribcage. (Even in anime women...)

 

* I agree with KenH about the crotch region. Either it's too low or the waist is too high.

 

Don't give up! It gets a lot easier after a while...

 

Additional resources: Sonofpat's rigging tutorials:

http://free.hostdepartment.com/s/sonofpat/Tutorials.html

[higginsdj]

'needs three rings' ????? No idea what you mean.

 

The bones in the body are the ones supplied by TSM2. So if I actually remove those 'extra' bones TSM2 won't care when it comes time to hit the TSM2 Rigger?

 

Re the model - well I shortened the legs from the original roto at mid thigh. I might stretch it back to original and then scale down (Y scale) from the waste. This will scale the crotch area down in proportion to the legs!

 

Cheers

[luckbat]

'needs three rings' ????? No idea what you mean.

 

Nothing complicated. Check out step 88 of Colin's Cooper tutorial, where he explains the elbow joint: http://www.colins-loft.net/CoopTorso.html

 

The bones in the body are the ones supplied by TSM2. So if I actually remove those 'extra' bones TSM2 won't care when it comes time to hit the TSM2 Rigger?

 

Oops. My bad. It looks like TSM uses those extra bones to accomplish the new stretchy-arms feature. In a normal rig you wouldn't need them. So no, leave them be. Once the Rigger generates the final rig, they'll be replaced by a simplified skeleton.

 

I still think your shoulder bones should be pulled in a bit, though.

 

Re the model - well I shortened the legs from the original roto at mid thigh. I might stretch it back to original and then scale down (Y scale) from the waste. This will scale the crotch area down in proportion to the legs!

 

Do what you think is best, and let us all have a look when you're done...

 

What rotoscope are you using? A photo? A sketch?

 

As I mentioned earlier, I urge you to either shrink her ribcage or widen her hips.

 

Getting back to your original question, remember that you can (and should) save a copy of your TSM2 skeleton before you run TSM2 Rigger. Here's how your workflow should go:

 

1. Make a copy of your pre-rigged model.

2. Run the Rigger on the copy.

3. Play with your new rigged model.

4. Take note of which joints look okay and which ones don't.

5. Go back to your pre-rigged model.

6. Move some of the problematic bones around.

7. Double-check your work in an action window, with the connected bones IK-locked.

8. If it looks good, return to step 1.

 

Obviously, you should try to do as much troubleshooting as possible in steps 6 and 7, since that's a lot quicker than constantly rigging, testing and reverting.

 

Remember to apply your Smartskin and fan bones (and CP weights) to the pre-rigged model! And only after you're done making changes to the skeleton.

[higginsdj]

Ahh - Spline rings - now I follow. I found some useful links for Hip and Shoulder bone setups that look interesting and will explore those.

 

I'm going to try to 'shrink' the ribcage. somewhat. The Roto was a Shi drawing (front and side) supplied by the copyright owner some years ago when he put out a request for modellers to generate a 3d model for him so I was guestimating the ribcage/shoulder area of the model when splining her.

 

I've been following the TSM2 procedures and have lots of stage copies :-). I have some terrible deformations in the hip area whilst the shoulders, knees and elbows are manageable but easily fixed.

 

Cheers

[luckbat]

Sounds like you're good to go. I look forward to the WIP renders...

[Paul Forwood]

Luckbat, it is very pleasing to see someone giving out good advice on rigging. Well done.

[luckbat]

It's the least I can do. If it weren't for the advice I've gotten from the A:M forums, I'd still be posting "How can I make a 5-point patch?" threads in the New Users section. I owe you guys.