Smooth Joint for Bone Pairs

[Greenlaw]

There's something I'm not quite understanding about this tool and I'm hoping somebody here can help.

Let's say I have a bitmap layer of an arm and I want to rig it using three bones. I can use Create Smooth Joint to smooth out the elbow but once I do that, it seems I can no longer get the descending hand bone to have any influence on the 'hand' part of the image. It's as if activating Create Smooth Joint activates only the pair and it overrides any other bones I had affecting the layer.

I'm sure that's not right and I'm just missing some info for keeping descendent bone(s) active. Does anybody know what I'm doing wrong here?

Thanks in advance for any help.

G.

[Greenlaw]

The videos I've seen on this topic simply ignore the lower bone (i.e., the 'hand') and never demonstrate the bone's affect (or lack of affect) on the lower part of the limb. I'm beginning to think this only allows the pair to be active for the whole layer, and I'm supposed to chop off the hand and put it in another layer. Is this correct? If so, that's unfortunate because the hands need be seamless with the wrists (and the feet with the ankles for that matter.)

Ugh! I think I'm going to have to chop off the hands and feet and just live with that, but I was really hoping to keep the limbs whole.

G.

[Pierre Gombaud]

Hey everyone, it is my first post on the forum!

I've got problems too to get the smooth joint to work right.
In this video (at 7:37), the guy uses the smooth joint on what it seems to be a rather "big" image file:

(direct link at the right time: https://www.youtube.com/watch?v=5G9v6XAQjj0#t=457)


My problem is the smooth joint is grayed out in the menu, if I try to use it on a "big" (200x900 px) image file.
It seems to be enabled only if I try to use it on a rather small image (20x70 px)... I've tested with PNG (both with and without transparency) and JPG.

So, is that normal or am I doing something wrong?



As for the problem Greenlaw is having, from my personal tests, it seems that no you can't use smooth joint on more than 2 bones in a row on the same image.

[Greenlaw]

I actually posted this quite some time ago but thanks for answering anyway.

Regarding my original question, yeah, that's a limitation in the tool. It only works between two bones for a single layer, and additional pairs you select for Smooth Joint will not affect the same layer. To be clear, that's not a bug, it's just how the tool works. Unfortunately, that made the tool inappropriate for the characters I had designed at the time because the elbows and wrists needed to be seamless, and I abandoned this approach for standard methods. I think if you intend to use Smooth Joints for Bone Pairs, you need to have it in mind early on when designing your characters.

As for your request, check the angle of the bones. Another limitation of this system is that the bones must be in a straight line. Otherwise, the option will be grayed out. If the joint angle is a few degrees off from zero, you may not have this feature. The max angle it allows can be 10 degrees but it's not consistent about that value--five or so seems to be a more practical limit. Above 10 absolutely won't work. My assumption is that the software allows a small angle in the joint to help the IK system but if you pre-bend the joint too much it makes the Smooth Joint less effective.

As for resolution, I just now tried a test using a 1280 by 960 image and it worked fine here.

Hope this helps.

G.

[Pierre Gombaud]

Thanks for your answer, Greenlaw!
It is indeed related to the bone angle, as I did some new tests with bones in a straight line and it works fine, but it won't work if a bone is rotated.

I think it is safe to say this feature is going to be better in a next ASP release, because as good as the idea is, it has very limited possibilites right now...

[Víctor Paredes]

Sadly, Smooth Joint works only with two bones per image, so you can't bend that image with any other bone.
The simplest solution is to create another layer for the hand, but I just discovered another trickier but faster solution that works very well in most cases. I made a little tutorial, check the video:

[Greenlaw]

Wow, Selgin, you are tricky!

G.