• Bugs

  • IK bugs in editor

    Dutch

Hello, there! Since it's my first post here, an introductory paragraph first. If you wanna cut to the chase, just skip it! 😃
I'm a veteran in bone based 2D animation, coming from Anime Studio, and I've been lurking on the forums for maybe 3 weeks now. Just purchased it the other day, and gotta say: I'm LOVING Spine so far! The effort you guys put in optimizing the workflow and making the overall experience more pleasing is nothing short of remarkable. Photoshop "Generate Assets" + automatic asset update = INFINITE HAPPINESS!

Anyway, I've been using the editor for a couple days and stumbled upon a few glitches while using the new IK controllers that I found were worth reporting, as I couldn't find other topics talking about it.

  1. Resize bone command doesn't work when the bones are under the influence of an IK constraint. The only way to edit that is by bringing the IK contraint influence to 0 and then making the adjustments, and finally turning it on again. Not something that is keeping me from working, but when you need to finetune the animation this kinda slows the workflow.

  2. Sometimes when the IK target position of a bone is very close to the position it already is without influence of IK, said bone will complete a 360 turn when you pull the Mix bar of the IK constraint between 0 and 100 influence. Checking or unchecking "Positive" in the Bend checkbox doesn't help (I wonder if it has to do with the parent bone's angle crossing the threshold that decides for a positive or negative spin). This happens in a 2 IKs chain very similar to the setup you guys show in that dinossaur mount demonstration video.

  3. When the Auto Key mode is on and you drag the IK Mix bar around, the editor apparently considers each and every step of your movement across the bar as a keyed command (the key icon in front of the constraint on the hierarchy view blink like crazy), and very soon the editor runs out of Undo slots!

Hope that helps with refining this awesome feature!

Cheers

Related Discussions
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Welcome! 🙂

Glad to hear you like working with Spine!

  1. You can click to visibility dot next to the Constraint node in the tree to enable FK editing while mix is not 0. You'll then be able to see both FK and IK at the same time.

  2. I'll see if I can reproduce this when I get home in a couple of days, not sure if it will be an easy fix though.

  3. Oooopsie, I'll let Nate know about this one, it should never key anything while playing back. Thanks for the report!

Hey there, thanks for the tip with the visibility on the IK contraint - that should speed things up a bit!

On bullet 3, the problem doesn't happen when the animation is playing; it happens while you are setting up a value in the Mix bar. Imagine that the animation is NOT playing, and Autokey is on - if I hold down the left mouse button and drag the Mix bar to tweak its value, instead of having a key created when I release the button, Spine will create a key probably at each and every loop of the application. It is easier to spot the problem if you keep looking at the key icon besides the IK constraint in the tree view - if you're holding down the mouse button to drag the Mix bar, you'll see that icon very quickly blinking in yellow and red.

Anyway, not a big deal 😉

Aha! gotcha 🙂

Another one:

if I have two IK constraints, one has "Positive" checked in the Bend property and the other one doesn't, and then I select them both (ie to translate them during animation), they'll both change to either have the checkbox checked or not, effectively causing one of them to bend in a way it isn't supposed to. The changed property will be retained even if I then deselect them both (but will reset if I go to another frame and then back without autokey on).

Take a look, this one is probably easier to understand with a picture 🙂

Thanks! reproduced it here. Interesting bug. Took me a while to reproduce it, but I realized I had to select the foot tip constraint first and THEN the ankle constraint. Instant flip.
Nate has been notified! 🙂

4 days later

1) By resize you mean scale? Yep, turn off the IK constraint as Shiu mentioned.

2) The IK constraint could rotate 2 directions when mixing between IK and FK, so it chooses the direction that results in the smallest rotation.

3) I see the icon blink, but if I undo it only goes back one step. This seems fine. Also, there is no limit to the number of undos.

4) Fixed in 1.9.16, thanks!

10 months later

I would use this topic to post another smaller bug with IK.

I'm working with an animation which uses IK on the legs, just like the video tutorial.
This is how i have the constraints.

Then i turned the constraint influence to 0, so to work freely with legs bones. (i was working on a jumping animation)
The first keyframe of the animation have 100 influence. The 2th frame goes to 0, 'till the second to last frame. Last frame goes back to 100.

The bug now is: At some point, the IK influence for a constraint, won't stay to 0. I have a 20 frames animation, and at frame 8 the ik is 0,9999-many numbers.
Even if i manually set it to 0 via keyboard, it will reset as soon as i deselect the keyframe (or reselect it).
Seems that only That specific constraint gives this bug.

(I've forgot to write the name of the IK on the pic! The selected one is Tom, which is having an hard time due his small influence driving him around in the animation. Bob, on the right, is just fine and at 0 influence, so he doesn't care about what i do with his beloved bones.)

This, so far, isn't an heavy bug and the animation comed out well. It is just a time-drain bug which forced me to set influence to 0 every time i had to modify something in that keyframe. Pretty annoying! =o=

That's all. :3
I hope these images helps to you to find the problem, and also hoping you can understand my messy english.
Help Tom & Bob to stay together! D: