Animation differences when exported and viewed in Skeleton viewer

jimbobjim

Hi,
Bit of a puzzle, I have animated a train in Spine. The drive rod animates correctly in the Spine editor itself but doesn't look correct when in-game & also when I check the export in skeleton viewer.

Here it is animating in the Spine Editor:

Here it is animating in Skeleton Viewer:

I've had graphical differences between assets in Spine and their exported versions (usually blend modes), but never animation differences... So I'm a bit stumped. Has anyone come across this before?

If it's any help, I'm using Spine 3.7 - this is due to compatibility with the studios sdk.

Thanks,
James

Spinebot

Looking at your issue, it's unusual to see animation differences between the Spine editor and Skeleton Viewer, since the Skeleton Viewer uses the same runtime as would be used in-game - it's purely rendering the exported data without any editor-specific behavior.

A few things to check:

Export settings:

Make sure you're exporting with the correct settings and that all the bones, constraints, and attachments involved in the drive rod animation have their Export property checked. You can verify this by selecting each element in the tree and checking the Export checkbox in the properties at the bottom of the tree.
If any attachment is not exported but is keyed in animations, those keys won't be exported either.

Constraints:

If you're using IK constraints or transform constraints for the drive rod, double-check that they're all set up correctly and are being exported.
Verify that the constraint order is correct in your setup.

Version matching:

Since you mentioned using Spine 3.7 for SDK compatibility, confirm that the Spine Runtimes version you're using (both in-game and in Skeleton Viewer) exactly matches 3.7. Even minor version mismatches can cause issues.

Debugging approach:
Since the issue appears in both Skeleton Viewer and in-game (but not in the editor), this strongly suggests either:

Something isn't being exported correctly
There's a version mismatch between your editor and runtime

Could you send your Spine project file to contact@esotericsoftware.com? Mention this forum thread so they have context. This will help identify exactly what's causing the difference between the editor preview and the exported animation.

jimbobjim

Think this is the issue:

Version matching:

Since you mentioned using Spine 3.7 for SDK compatibility, confirm that the Spine Runtimes version you're using (both in-game and in Skeleton Viewer) exactly matches 3.7. Even minor version mismatches can cause issues.

SDK and the skeleton viewer version we use are 3.6. So it looks like IK constraint data is being stripped/changed.

Thanks.