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Joint with ZERO Volume Loss only 3 bones (my first post)

Posted: Sun Oct 12, 2008 9:00 am
by Birdy
Sorry if this has been discovered before. There is more you can do with this and the 'crease' is made with sorting the three shapes. You can make the crease on the other side (IE upper joint in 'front' by simply changing the shapes order. I just thought there "had" to be a simple way to do this. You can have a whole chain of these joints and the higher ones will not move as you rotate the lower ones. Seems very very stable. The ball joint in the middle can be used other ways but I hope this sparks you guys to 'go with this' and make use of it.

ImageImageImage

ImageImageImage


3BoneJoint.mov

3BoneJoint.anme

Sorry if this was done before. But thanks for all the good tips and fun
read (I've been lurking a half year now)

Here is an example of a 7 bone leg (not perfect but not as hard as some more hit an miss things.

Image

And the file

7BoneLeg.anme

dem bones

Posted: Sun Oct 12, 2008 1:47 pm
by toonertime
thanks for the demo on dem bones!

I think bone restraints would also be of use.

I have saved your AS file for future reference!

Posted: Sun Oct 12, 2008 1:59 pm
by mkelley
I think this is good to point out, as for many folks it will be all they need.

Unfortunately, for those of us who don't want a crease when the joint bends this won't do at all -- in those cases, Vern's rig is still the best solution.

Posted: Sun Oct 12, 2008 2:58 pm
by Birdy
As far as having NO crease you just have to make a mask (or use the masking in AS but I have not tried that yet)

You place a shape that is all blue (in this case) on top of the top shape to mask it but a tad smaller to allow the black (in this case) edge to still appear. You then bind BOTH upper shapes to the same top bone. One will go above the bottom line 'erasing it' the other provides the line.

Here is a NO CREASE video, file, and pic to show you what I am trying to say.

Image

nocreasejoint.mov

no Crease one.anme


Once again you just have to play with the shape levels(what order they are stacked) to get the result (with the added shape for no crease that is)

Hope this helps those that DON'T want a crease and that could use this.

Posted: Sun Oct 12, 2008 4:14 pm
by synthsin75
That's basically what I usually do.

Some people won't use it because it's really just cutout style rigging. There's no 'flexing' at the joint you'd get with the joint under the regional influence of both bones. A lot of people really like that flexing.

A couple of thoughts...

Aside from killing the IK chain (the forearm bone nolonger moving the upperarm bone), you don't really need that small third bone for this. But some people don't like full IK.

You can add a couple of vector points to the upperarm, just a bit above the joint (one on each side). Since this whole arm is point-bound, you can then increase both bone's regional influence to cover these new points. You may need to select the two bones, select these new points, and do 'Bone>flexibind points'. This will add a bit of automatic 'flex' to your rig.


Welcome to the forum!
:wink:

Posted: Sun Oct 12, 2008 5:05 pm
by mkelley
Yeah, I guess that's what I meant, Wes (the flex you get with bones influence). While it's hard to say that my cartoons look "natural" in any sense of the word, I need that flexation not to look totally cutout.

But folks who like the cutout style will benefit from this.

Posted: Mon Oct 13, 2008 2:45 am
by heyvern
I've done some experimenting with image "puppets" in AS and this is the technique I've used a few times. The "ball" joint can be great for images if there isn't too much detail that needs to "line up".

For image type puppets this works well when you use a feathered or soft edge transparency on some of the parts so they invisibly blend into the ball joint. That ball joint is great because it can extend the rotation of the joint. One part can cover a lot of the rotation but the ball joint can extend further to cover the joint. With images though, the ball joint has to be a separate layer. I'm not explaining well.

This is good technique. I do however agree that it is too "fixed" for my tastes for vector type joints. I like a little "bulging" and flexing of the joint but that's just me.

Another drawback is where the stroke joins or overlaps at the ball joint. There will be a "nick" or triangular chunk at that spot. Probably not that noticeable but it is there. I suppose HD out put might show this more... or a thicker stroke at higher resolution. That join also is never going to be perfectly smooth. there will always be that slight "bump".

These are nit picks of course. Just my thoughts on it. It is simple AND effective... which for some is important... i always have trouble with the "simple" part when coming up with techniques. ;)

-vern

Posted: Thu Oct 16, 2008 6:24 pm
by slice11217
Personally, I've always used this technique ever since I found out about it:

viewtopic.php?t=4970&start=0&postdays=0 ... ght=joints

Seems to work pretty well for most things. I hadn't thought about putting a ball in there... what's the advantage?