Canvas3D is being deprecated because the current maintainer proposed it should be. Also don't think this decision was made "hastily" because there has been very little activity on Canvas3D in a long time. See the merged commits to Canvas3D (most of which are just bumping the version).
https://codereview.qt-project.org/#/q/canvas3d+status:merged,n,z
In practice any module can be brought out of deprecation if someone is interested in taking over maintainership responsibilities of that module and there is sufficient interested in actually developing and maintaining a module as new Qt releases are created. For Canvas3D there just wasn't that much interest and development going on there, so I agree with the proposal to deprecate it. I suspect there are many other modules in Qt that are in practice unmaintained and in some cases might not even have an active maintainer to propose deprecation.
By misrepresenting unmaintained modules as maintained by just "keeping them around" for release after release, we do ourselves a disservice by reducing the overall quality of Qt.
Regards,
Andy Nichols
-----Original Message-----
From: Development <development-bounces+andy.nichols=***@qt-project.org> On Behalf Of Miller, Douglas K. CONT NAVAIR 2109, 1, N139
Sent: Thursday, November 8, 2018 9:00 PM
To: ***@qt-project.org
Subject: [Development] Deprecation of Qt Canvas3D in 5.12
I just realized from the Qt 5.12 New Features posting that Qt Canvas 3D will be deprecated in 5.12. I'm working on my second application that uses it now and I'm concerned that the decision to deprecate it has been made too hastily. The real advantage I see in using it is that it offers a three.js development environment which is higher level, has plethora of code that can be easily ported to the Qt Canvas 3D, is well documented, has a lot of books published for it. It seems to be the most productive way to do 3D graphics programming in Qt unless there is a need for higher performance. Qt 3D has several advantages over Canvas 3D, but is disadvantaged in all the areas where I mentioned that Canvas 3D/Three.js excels. So, can we please keep longer?