Physics Constraint LOOP

rahulyadav

Hi everyone,

I'm working on an animation using Physics Constraints, and I’ve run into a strange issue. In the timeline, everything looks correct — especially at the first and last keyframes where the object is supposed to start and end at the same position. However, when I export the animation (using PNG sequence), I notice a slight discrepancy between these frames in the PNG Preview window, which is also confirmed once I import the sequence into After Effects.

To try and fix this, I attempted using the Mix node inside the Physics Constraint, but it didn’t resolve the mismatch.

Has anyone else faced this issue? Any suggestions on how to make the exported frames exactly match what’s shown in the timeline preview?

Erika

rahulyadav You have to enable Warm up when exporting, usually a Warm up of 1 is fine, but you may need more if your loop is short and the physics are lingering for long.
https://esotericsoftware.com/spine-export/#Warm-Up

rahulyadav

Hi @Erika , I’ve tried the suggested solution, but I’m still encountering the same issue when exporting a PNG sequence. Specifically, the problem happens when the preview window opens during the export process.

Erika

rahulyadav I just tested it again in the latest beta on Celestial Circus and it worked correctly, I tried to have an animation playing in the preview view too and it still exported as expected.
We'd love to fix the problem but it's not possible if we can't reproduce it. Could you give us more details and more precise steps to get the problem too?

Nate

Please make sure you are using 4.2.42, as we recently fixed an export bug with constraints that have 0 mix in setup mode.