Translate/Rotate (Advanced) – exact 90° backward rotation causes a position “jump” (unexpected translation), while 90° f

[Jay_Ki]

Title: Translate/Rotate (Advanced) – exact 90° backward rotation causes a position “jump” (unexpected translation), while 90° forward is fine; 89/91 or 90.0001° works

Hi CloudCompare devs,

I’d like to report a reproducible issue I’m seeing in the Interactive Transformation tool.

Context
- Tool: Edit > Translate/Rotate (Interactive transformation), using the Advanced panel
- Symptom: the rotation itself looks correct, but the entity position suddenly “jumps” (as if an unexpected translation is applied).

Key behavior
- Rotating by exactly 90° in the “forward” direction works normally (no jump).
- Rotating by exactly 90° in the “backward” direction causes the position jump.
- 89° and 91° do not show the issue (backward is fine).
- Workaround: 90.0001° (instead of 90.0000°) works fine, including in the backward direction.
- Another workaround: applying +90° in multiple steps (validate/apply each step) can be stable, while a single -90° step may jump.

Steps to reproduce
1) Select a mesh/entity.
2) Open Edit > Translate/Rotate.
3) In Advanced, set Rotate Around = Origin (or the default/automatic setting), and set the rotation axis to Y.
4) Set the angle to exactly 90.000000 degrees.
5) Click “Forward” rotation: works normally.
6) Click “Backward” rotation: the entity position jumps.

Questions
- Is this a known issue with Interactive Transformation at exact 90° (backward only)?
- Is the recommended workflow to avoid exact 90° in this tool (e.g., use 90.0001°), or to use Apply Transformation (Ctrl+T) / a custom coordinate system pivot instead?

Thank you!

Note: I’m a non-native English speaker, and this post was written with assistance/advice from ChatGPT (GPT-5.2).
```

[daniel]

I can't reproduce this on my side...

Which version are you using and on which OS?

Has your mesh very large coordinates maybe? (I'm trying to look for particularities). Or can you share the mesh with me maybe? (admin@cloudcompare.org)

[Jay_Ki]

I've sent e-mail.