Feature request: Turntable view navigation

[Lunarien]

Add a way to switch the way I rotate around my model. Specifically at least turntable rotation in which i rotate mostly around a single axis. I am not quite sure how to explain how it works, but the big CAD programs (FreeCAD included) all have this implemented.

I guess a way to explain it could be: the vertical axis stays vertical constantly no matter how i rotate my view around. If you project the axis line onto your screen (or just watch the axis), it should always be going vertically, up/down. it will only be stretched in various amounts (visible if the axis doesnt stretch infinitely)

[mmiscool]

Currently I am using the threejs ArcballControls.

Link to the docs related to that. There are several other options but the arcball controls seem to work the best for CAD applications.

You can experiment with swapping them out and if you find a different type of controls that you like I might be able to add a drop down in the setting panel to select a different one.
https://threejs.org/docs/#ArcballControls

If you look at this file you can see where they are being imported and set up. You should be able to import a different set of controls and try out the other ones to see if they are to your liking.
https://github.com/mmiscool/BREP/blob/da1c0b495fd6bd9d7d334b87ae5b70302eb1b280/src/UI/viewer.js#L7

[Lunarien]

I tried the most promising-looking controls (OrbitControls) and i like those more. However, the fact that i cannot see the pivot along which the view rotates makes it rather confusing to look around the model.. That's for another issue, though.

Thankfully, it was mostly enough for me to basically just replace ArcballControls with OrbitControls in the code. Then I just removed line 261 (in the current code in the file you linked) to avoid an error.

This code replacement alone does not satisfy my desires fully, though. It does not, for example, account for changing the up axis, which would probably have to be implemented. It behaves weirdly when i change my view to one of the sides of the rotation preview cube (in the bottom right corner of the 3D viewport).