Inversing scale transform constraint does not work in Godot runtime

CrusaderDude

I am using the Spine GDExtension for Godot 4.4.1.
I am using a transform constraint for a bone that inverses the scale value of another bone, to do a simple fake 3D effect.

Here is what I made, as the front of the door shrinks, the side grows (it has a second constraint to match position).

But here is a recreation of what I get in Godot, which is that it doesn't scale the side.

Is this a bug, or have I missed anything here as to why it doesn't work as expected?

Spinebot

I'm sorry to hear you're experiencing this issue with the transform constraint in the Godot runtime!

Based on my knowledge, there was indeed a bug that prevented scale and shearY mix from being negative in transform constraints. This issue has been tracked and fixed. You can see the details here: Transform constraint should allow negative scale and shearY mix · #1227

Since you're using the Spine GDExtension for Godot 4.4.1, you'll want to make sure you're using the latest version of the spine-godot runtime that includes this fix. The bug fix should allow your inverse scale transform constraint to work properly.

If you're still experiencing issues after updating to the latest version, there are a couple of things to check:

Make sure the Local checkbox is checked in your transform constraint settings, as this can affect how the constraint behaves with scale operations
Verify that your constraint order is correct - you can check the constraint order in the constraints node

If the problem persists even with the latest runtime version, it would be helpful to email your .spine project file to contact@esotericsoftware.com so the team can investigate the specific setup you're using.