Change to flipping bones in version 3.0

Lt. Action

Hello!

Quick question regarding the newest iteration of Spine.

I updated to version 3 and loaded a file I had been working on that contained several instances of bones flipped in order to save space on the atlas. I did this to avoid the redundancy of, say, having two identical arms for a character, the only difference being that one points left and the other right.

When I loaded this file, I received a message that said the flipping was no longer supported.

My question is does version 3 have an alternate solution to achieve the same effect or has the function been dropped entirely?

Thanks!

Pharan

If the flip doesn't move, the solution is to set the attachment scale by -1.
If it does move, the solution is to set the bone scale by -1.
Whatever the axis you need, of course.

Nate

Flipping by setting the attachment scale to -1 has always worked. Bone flipping is now gone, instead use -1 scale. Note it works slightly differently: previously bone flipping always used the world axes. Now, using -1 scale the bone is flipped using its local axes.

Lt. Action

Ahhh I see!

I never thought to look into that given the convenience of the little ol' check box!

Thanks for the assist!

Nate

Hehe, at first everyone expects negative scale to flip because that are used to that, then they get used to the nice flip checkbox, now they have to go back to negative scale. At least we got to the right solution in the end! 😃 Doing negative scale from the start would have made many things harder.

Lt. Action

Thanks, Nate! I get where you're coming from and understand the change.

While I was messing around with it things were falling into place, but I have one more related question.

On a test animation I'm working on I flipped the root with the "x Flip" box just to see what would happen and it worked fine, but when I set the root to have a value of -1.0, it didn't produce the same results.

Loading Image

I opened the tree and several slots still had two positive scale values, what am I over looking?

You and Pharan have been very helpful, I'm sorry to have to ask so many questions!

Søren

Nate might be able to answer this without the project at hand since he knows the math behind it. But if you could send the project to contact@esotericsoftware.com I can take a look at it and see what causes the issue you're having.

Nate

It's hard to tell from the pic what part of the rig is messed up. Note flipping the root using negative scale won't flip child bones that have scale inheritance disabled.

Lt. Action

Nate/Shiu,

Thank you again for the help! I am quite masterful at forgetting to key stuff and overlooking crap when I'm working.

I believe the child bones are inheriting the root's scale given that the model pictured is scaled up uniformly applying a 1.5 scale to the root (for the record, I am 99% sure what's happening is user error).

I appreciate the offer to have you take a look at the project but this isn't actually an issue given our needs for this project, I was just messing around to see if I could get comfortable with compensating for the lack of the "flip x" function if we ever switch up to 3.0.

If it becomes a blocker for an unforeseen future need I'll take you up on the offer!