Marquee selection problematic when working in perspective view mode at canvas proportion height/width > 1, or in ortho mode

[ahhhchuen]

When under perspective view at canvas proportion height/width > 1, or when orthographic view is action, marquee selection becomes problematic.

[ahhhchuen]

Perspective view marquee selection fixed and pull requested applied:
improved section (slice) tool and marquee selection tool #240

Ortho mode yet to fixed. Marquee selection disabled during ortho viewing.

[NiklasPor]

Just also ran into this, makes orthographic mode kinda unusable if your users are working a lot with marquee selections.

Screen.Recording.2025-10-21.at.12.27.29.mov

[xeolabs]

Hi @NiklasPor, thanks for your comment. This video however doesn't give us enough info - there are various possibilities here, including misalignment of canvas coordinates due to CSS/HTML layout. In fast in the video it seems to be that the pointer coordinates are offset, but I can't be sure.

Could you please provide a self-contained example to reproduce? Thanks

[NiklasPor]

Sure I can prepare one, but basically when I switch the perspective view mode to orthographic then this selection won't work anymore, like described in the base issue.

Ah wait, this is the viewer repository not the SDK one. Yeah I can also open a new issue in the sdk repository.

[NiklasPor]

@xeolabs you can find a reproduction here: https://jsfiddle.net/6jmac1vL/5/
The only thing I changed from the marquee example is that I added this:

    viewer.camera.projection = "ortho";

[xeolabs]

@xeolabs you can find a reproduction here: https://jsfiddle.net/6jmac1vL/5/ The only thing I changed from the marquee example is that I added this:

    viewer.camera.projection = "ortho";

Could you please modify that example so that the mouse (attempts to make) makes marquee selection, instead of moving the camera? Thanks

[NiklasPor]

It's the default marquee example from the xeokit-sdk example library with the marquee mouse control. You have to hold down the mouse for a few seconds before the marquee selection starts.

Screen.Recording.2025-10-21.at.15.26.48.mov