Character's limbs going through target bones

[Rnoir]

I've already created some characters and rigged them on Moho, gave them target bones, added angle constrains on the limbs that I wanted to look right, animated them and everything was working good and dandy. But since a few days ago I've been having a problem with target bones whenever I try to rig a new character that's driving me utterly mad:

For some reason, I create as always a pair of target bones (one for each leg) but as soon as I add an angle constraint (of -140 maximum and 0 minimum) to both bones, ALWAYS and ONLY the bone of the leg behind (in this case, the character's left leg) goes through the bone and never collides with the ground. Not only that, if I try to manually flex the bone by graving the target of that leg, it just doesn't works. And it only happens with new characters I create. Somehow if I rebuild from zero the rig of previous characters files containing all their layers, this problem doesn't comes up.

Here's a picture to explain what's going on:



Here I also uploaded to dropbox two files for anyone who'd like to tinker with it: "https://www.dropbox.com/sh/m6mef3kwc94p ... gBtIa?dl=0"
It's a .PSD file (since I mostly work with image layer based characters. Also, it's CS6 version) and the .moho file that already has the character rigged with a small animation to depict the problem. I colored the bones that work allright in green, the target bones in yellow and the defective leg bone in red.

If anyone knows how to work this out, I'd be really greateful.

[Greenlaw]

I haven't had a chance to see your file yet but I've seen something like this before. It happens rarely but I think a bone can sometimes get internally corrupted, causing some features to behave oddly.

Try these things on a backup file:

1. Delete Target and create a new one. That's probably not going to work but it's the easiest thing to check.

2. If the above doesn't work, try deleting the targeting bone and creating it. You should unparent any child bones first of course. This one will probably fix the issue.

I think I see this happens after I've copied an existing bone setup instead of building it from scratch. Normally that isn't and shouldn't be a problem, but I don't know...just a guess.

Hope this helps.

[Rnoir]

It happened to me rarely like you said, and I was always able to fix it by deleting the target or the bones related to that target and building a new one. But now it happens %100 of the time and I can't tell what triggered the absolute persistence of this problem.
I already tried what you said and nothing. Strangely enough, I tried to add some stretch to both bones to see how the conflicting bone (or target) worked and even there the bad bone doesn't behaves like it's counterpart which, having exactly the same angle constrains and stretching numbers, works as it should. Here's a screenshot of what happens:



I encourage you to try out my files to see if it happens the same in other systems with moho or if it's just happening to mine. I already uninstalled it and installed it again but nothing changes. I also tried it out in both 64bits and 32bits versions of the software, yet the issue remains.

[Greenlaw]

Yeah, that is weird. I'll take a look at the file at lunch today.

[Greenlaw]

I took a look and 'fixed' the issue in the scene you uploaded.



I'm not sure what was wrong with it but here's what I did:

First I tried replacing the lower leg bone but, as you already found, that didn't do anything.

So I went up the chain and replaced the upper leg bone. That seemed to work.

I'll take another look at this tonight but I suspect there is something broken internally in that upper leg bone, and replacing it is probably the quickest fix.

Another user ran into this nearly identical problem a couple of weeks ago, and replacing the lower leg fixed that one. We never figured out what triggered the problem though.

[Rnoir]

Following what you said, I think I might have found the issue.
Apparently, the problem is not the target but the lower leg bone, as it has to be somewhat curved to the direction of the knee because otherwise (if it is slightly curved opposite to the direction of the knee) it will block the leg from flexing as soon as you give that bone an angle constraint.

It makes sense, but at the same time, it's kind of an issue if you have some weird-limbed character that needs to have angle constraints but it's legs don't work as expected.