TransformControls: Improve gizmo rendering with orthographic cameras.

[Mugen87]

Fixed #24208.

Description

This PR implements the suggestion of #24208 (comment) to mitigate the issue of disappearing gizmos when using TransformControls with orthographic cameras.

[mrdoob]

Thanks!

[deethee]

Hi this fix did fix the problem of the gizmo disappearing but it creates a new problem with transformCotrols and rotation. This is nolonger possible!.

[Mugen87]

Do you mind explaining in more detail what's going wrong?

[deethee]

Well if you have a orthographic camera and you want to use the Z rotation of the transformControls (hide the other axis) than you cannot rotate the object anymore, nothing happens. Without the fix you are able to rotate it. If you do not hide the other axis you are somehow able to use the "wrong" rotation axis to rotate that object. For me it feels that the pivot is than somehow wrong aligned.

[mrdoob]

@deethee could you share a screen recording?

[Mugen87]

I've tried to reproduce the issue for quite a while now but without success. A video would be indeed helpful.

[deethee]

Without the bugfix I can rotate the triangle by the z axis. The other axis are hidden:

With the bugfix I can drag the rotation handle but nothing happens: (so, I am not sure if nothing happens or if it is rotating the wrong axis)

This is orthographic camera only.
If I show all axis I can rotate the triangle by the yellow rotation handle not the blue. This is with the patch:

By the way, as you see the color schemes are bad you hardly see the handles.

[Mugen87]

Strange, the gizmos look completely different compared to the current version. Are you using an older version of TransformControls?

[deethee]

Yes I use R124, but the initial bug was in master too.

[Mugen87]

I'm afraid we can't ensure that patches also work with previous versions of the library. If you want this issue fixed, you have to upgrade to r142.

[deethee]

Does that mean you don't have this rotation issue with the r142 and the fix applied?

[Mugen87]

No, was not able to reproduce the issue so far.

[deethee]

Hi, I just updated to latest Three release and the problem does remain. Without the patch the rotation does work.
http://jsfiddle.net/3dyzhv9e/

[Mugen87]

It does not seem to work with r124, too: http://jsfiddle.net/k2c6Lj7b/3/ 🤔

[deethee]

Does not work with actual version 142 also: http://jsfiddle.net/vb6t4zx5/

[Mugen87]

In any event you are not reporting a regression. It's seems to be an issue that always existed in TransformControls, no?

[deethee]

No this bug has been introduced with the upper bugfix #24208 . The bugfix fixed errors with the transformControls Gizmos disappearing and the drag event being interrupted. This problems were fixed but now the z-rotation is no longer possible.