Physics Constraints not working in 4.3.39-beta project

MadPropz101

I started my character in the 4.3.39 beta version of Spine, and my Physics Constraints aren't working. Usually, when I create them, they work right away, but now they don't work on existing bones or new ones. In the attached video, I demonstrate creating a couple of bones and trying to move them around, but the Physics aren't affecting them. Sorting constraints didn't fix the issue.

Spinebot

It seems that the issue with Physics Constraints not working in the 4.3.39-beta version of Spine might be related to the recent changes in the beta updates. As noted in the context, there have been changes related to physics in previous beta versions, and sometimes the runtime updates lag behind the editor updates. It is recommended to wait for the runtime update that aligns with the editor changes. Alternatively, you can revert to a previous beta version, such as 4.3.14-beta, where the constraints were functioning as expected. To do this, export your project data in JSON format and import it back into the older version.

MadPropz101

Spinebot Does 4.3.14-beta support all features that 4.3.39-beta has? I am using sliders heavily in my animations. If yes, can you please provide step-by-step instructions on how to downgrade my project?

MadPropz101

I must mention that the issue doesn't seem to be related to 4.3.39-beta, but to my project, as when I create a new project with the same version the Physics Constraints work as intended.

Nate

Earlier beta versions will have significantly more bugs. Spinebot is wrong, it is not supported to downgrade.

Mostly likely your constraint order is the problem. You apply physics constraints first, then other constraints (probably your slider, which can easily affect many bones, if not also others) are applied and you lose the changes that the physics constraints made. Constraint are applied in the order they appear in the tree, topmost first:
https://esotericsoftware.com/spine-constraints#Order

Drag your physics constraints in the tree to be after other constraints that change the same bones that the physics constraints change.

MadPropz101

Nate Hey Nate, could you please review the video again? When I change the order of the constraints, the issue persists. Here's a new video that demonstrates that even if I delete all other constraints, the physics still don't work.

Misaki

MadPropz101 In the video, the movement of your bones quickly reaches the limit for some reason. You can see this because the Limit section is highlighted immediately after moving a bone. Could you send us a Spine project that reproduces the problem via email?: contact@esotericsoftware.com
Please include the URL of this forum thread in the email so we know the context. Then we can take a look at what's wrong.

Nate

Nothing stands out as problematic. Can you please post a .spine file with the issue?

MadPropz101

Nate

Misaki

I sent the .spine project to the email. Regarding the Limit section being highlighted, it is always like that, even when creating a new project and a few bones, but the physics usually work.

Misaki

MadPropz101 Thank you for sending us the project! I think I have identified the cause. The reason why the physics constraints results were not shown was becauseInterpolated was turned off in the Playback view:

Even if it is turned off, the physics results will not be visible only when the bones are not moving due to animation, such as in setup mode. When the bones are transformed during animation, the physics will respond correctly. Please verify this on your end.

MadPropz101

Misaki Hey Misaki, you are right, this was the cause of the issue!

However, I don't want to use Interpolation in my project since I don't like the look, I am trying to get a feel closer to frame-by-frame animation. You mentioned that the physics should work in animation even with "Interpolated" off, but that doesn't seem to be the case. Am I doing something wrong? Can you confirm on your side that physics work in animation with Interpolated off?

Nate

Good job finding the problem, Misaki!

We see Interpolated working correctly when an animation is playing. When no animation is playing, in setup or animate mode, then you get no physics. We've fixed this in 4.3.40-beta!

MadPropz101

Nate Hi Nate, is there a way to use physics without Interpolation turned on? I want to have lower fps physics in certain animations to match the overall feel of my animations.

Nate

Yes! It should work when an animation is playing. It should also work when an animation is not playing once we release 4.3.40-beta.

MadPropz101

Nate Ah I see, being in Animate mode isn't enough, nothing happens if you move the bones around with your mouse. The animation actually has to be playing. Thank you!