Flipping skeleton

adunato

Hi All,

I am trying to get skeletons to flip correctly however after having worked out an editor workflow (http://esotericsoftware.com/forum/Flipping-skeleton-workflow-7162) I'm OK with I'm struggling to understand how runtime manages skeleton.getRootBone().setScaleX(-1).

The animations of the flipped skeletons (X scale -1) work perfectly in the editor but get deformed at runtime. All I do at runtime is:

skeleton.getRootBone().setScaleX(ANIMATION_SCALE * skeleton.getRootBone().getScaleX());
skeleton.getRootBone().setScaleY(ANIMATION_SCALE * skeleton.getRootBone().getScaleY());
skeleton.updateWorldTransform();

where ANIMATION_SCALE is a constant to downsize skeletons in the application.

What am I missing?

Thanks

Pharan

Instead of negative root bone scale, you can also use

skeleton.setFlipX(true);

spine-runtimes/Skeleton.java at master · EsotericSoftware/spine-runtimes · GitHub

adunato

Thanks Pharan. That's what I went for, coupled with renaming images + bones from left to right it works and keeps mirroring correct.

It doesn't matter for now but I'm still confused as to why scaling X to -1 works fine in the editor and it doesn't at run time, it looks as if the editor propagates inheritance between root and bones in the different way from runtime but I may be wrong.

Pharan

Yeah, it really shouldn't be different. Especially since you're using spine-libgdx, which is the reference implementation that the editor itself uses.

On a side note.

If you keep applying scale as (ANIMATION_SCALE * currentScale), wouldn't it progressively get smaller (or larger) if the value of ANIMATION_SCALE anything but 1?
You may want to apply ANIMATION_SCALE when the json is loaded so it doesn't have to factor into your root bone scale.

adunato

On a side note.

If you keep applying scale as (ANIMATION_SCALE * currentScale), wouldn't it progressively get smaller (or larger) if the value of ANIMATION_SCALE anything but 1?

You may want to apply ANIMATION_SCALE when the json is loaded so it doesn't have to factor into your root bone scale.

You are correct, that's an extract from the skeleton set up code. The skeleton.updateWorldTransform() call is misleading as probably redundant at set up time (I do invoke is during rendering), thanks for calling it out.

Nate

You are using spine-libgdx? What "gets deformed" when you use scaleX -1? Do your bones use disable inherit scale? In that case, they won't inherit the root bone's scale, so they won't flip. The skeleton setFlip flips regardless of disable inherit scale.

adunato

Yes, using spine-libgdx (latest version). I have not disabled bone inheritance but have just checked and in the exported skeleton json there is no "inheritScale" or "inheritRotation" which I think based on quick look at the code spine-libgdx is expecting to determine bone inheritance? Is there a way to enable / disable export of inheritance into the json from the editor? I just checked and both scale and rotation inheritance are checked in my editor projects.

Nate

If you are using 3.4.02 you'd see inheritRotation/Scale in the JSON. If using 3.5 you'd see transformMode. If you aren't disabling rotation or scale inheritance, then I'm not sure what the problem is. Can you provide a project that shows the problem? You can post here or email: contact@esotericsoftware.com

adunato

I'm using 3.4.02 and no inheritRotation/Scale in the JSON as far as I can see.

Just about to email you the project files + export.

Thanks

Nate

Thanks for the project. It looks fine at runtime even with the root bone scaleX set to -1. You said it is "deformed" when the root scaleX is -1. Please show a screenshot and also tell what runtime you are using.