Mouse dragging doesn't work on Ubuntu-25.10 nor Ubuntu-24.04.3 installed from deb from web site.

[krpi8429]

Describe the Bug
Mouse dragging doesn't work on Ubuntu-25.10 nor Ubuntu-24.04.3 installed from deb from web site.

SOMEthing moves, but I don't understand what and it isn't as documented. I can't figure out how to get it to do the isometric movements shown in either the tutorials or my class videos.

Steps to Reproduce

1. Create new project with arena
2. left click & drag

Expected behavior
I expect the behavior described in the manual. So do Perplexity, Grok, and ChatGPT.

Perplexity thinks there should be a "Navigation" section in preferences that I can use to reset but I don't find one.

Grok thinks I need to use control-alt for all mouse gestures in order to duck QT intrusion but that doesn't help.

ChatGPT thinks there should be a "View Mode" in Preferences but I don't see one.

Screenshots
Screen shots won't explain very well as you can't see the mouse. I'll include one anyway.

Screencast.From.2025-10-29.13-22-46.mp4

System

• Operating System: Ubuntu-25.10, also Ubuntu-24.04.3
• Graphics Card: Intel® Iris® Xe Graphics (TGL GT2) or AMD Radeon™ R3 Graphics

Additional context
Add any other context about the problem here.

[CoolSpy3]

Oh, yeah; I think I get what you're talking about! That sometimes confuses me too :P The camera's rotating about the camera center rather than rotating about the arena right?

That happens when you click on the background. (You can think of it as dragging the background kinda.) Try left-clicking on the arena when you start your drag motion. Then it will rotate around the arena like expected.

It's especially trippy when you're zoomed out like you are in the video. At least for me, zooming in on the arena gives a better "sense" for where I am in relation to the rest of the world. Then just play around with the controls for a-bit, and you should hopefully get the hang of it pretty fast :D

[krpi8429]

No. For me it doesn't rotate at all.

I've read descriptions of what you're saying but I haven't seen that yet.

[CoolSpy3]

? Really? In the video it looks like the camera's orientation is what's changing. (The motion you'd get by moving a mouse in a first person game.) Maybe I'm misunderstanding what you're trying to do. Can you describe more of the motion you're trying to achieve? (Or provide an example.)

I have a couple of related ideas, but I don't think any of them are what you're looking for:

• If you expand the Viewpoint node in the scene tree, you'll be able to edit all of the camera settings. Maybe one of these is what you're looking for?
  • Generally, position, orientation, follow, and followType are probably the relevant settings.
• It doesn't look like it, but if the camera is "locking-up" on one axis of rotation, it could be that the orientation vector's been messed up. (I had this happen when changing the coordinate system of a world file.) IIRC, that can be fixed by zeroing out all the values in the orientation field (see above).

Just to be sure we're on the same page, I've attached a video of what I think the behavior should be.

webots_6903.mp4

[krpi8429]

Thanks. That video helps. That's not what I'm seeing at all.

Here's another. Left button, middle button, right button on the background, then selecting the arena, left button, middle button, right button. Three mouse circles each, I believe.

Left and right button are different but none of these rotates around all three axes. I'm expecting to be able to rotate the arena into an isomorphic view like you do on left click on arena.

Screencast.From.2025-11-03.14-18-43.mp4

[CoolSpy3]

Huh... That's really weird... It almost looks to me like it's clicking on the background instead of the actual arena :/ I can't say I've ever encountered that. I'll try to mess around with some of the Ubuntu versions later and see if I can reproduce. By any chance, is it isolated to this specific world, or is it every world? (i.e. If you go to File > New > New World File , is the problem still present there?)

[krpi8429]

These have all been new worlds with arena. So I presume it's all.

[CoolSpy3]

Alright, I've managed to reproduce this with moderate consistency on a fresh install of R2025a on Ubuntu 24.04. For me, clicking somewhere on the background and then clicking into the arena and immediately starting a drag motion acts as if I had dragged the background (~30-50% of the time). However, I haven't been able to reproduce what you're seeing when selecting the arena and then dragging in the same place. My guess is that it's related to how Webots determines what you're clicking on in the world.

I did a quick scan of the relevant code sections, and my guess is that it has something do do with this block. Unfortunately, I'm currently trying to get caught-up with a backlog of stuff (both in Webots and in life), so I'm not 100% sure when I'll have the chance to investigate in-depth. In the meantime, you should be able to move around with a combination of rotations and translations (left & right click movements), although unfortunately, that's not as convenient as being able to rotate about specific objects. Sorry about that :/

[krpi8429]

Thank you for investigating.

No, I can't get around. I only get one axis of rotation. I've managed to move forward with my class but it's a pretty major nuisance.

[CoolSpy3]

Can you not do something like this?

2025-11-10.00-09-15.mp4

(Yellow is left-click; blue is right-click.)

You could also try going to View > Change View. If nothing else, that should move you to a different axis.

[ShuffleWire]

@krpi8429 did the help you received solved your issue :) ? Else please provide more infos

[krpi8429]

Well... what I learned is that Webots is really a windows only program. It's not supported on Linux and it's not supported on macOS. It might be in the next release, if there is one, but it isn't yet, so we shouldn't expect it.

It's sad because it's required for a class and I don't have windows but I have numerous other options. Trying to make Webots work is the hardest part of the class and not even AI has been able to help.

[ShuffleWire]

Hold on, it should work very well on linux !
I will try to understand what is wrong

[ShuffleWire]

Please note that you can still use the View->Change view menu, not very convenient, but allows to look at stuff...

[ShuffleWire]

I would like you to make a test : I would like to check if the Mouse API have the same issue.
It should call somewhat the same chunck of code, so let see in #6808

Please open this world mouse.zip
And see if, when you run the world, and then hover on a object, you should get non-nan value. (and get nan on the background)