Generalize the scale gizmo handles setting in the touch screen interface settings

[LunaCapra]

As it stands, most editor gizmo billboards/handles are fairly small, making it hard for me to use them.

I think it would be beneficial to have a multiplier for the scale of billboard gizmos.
It could potentially be a slider, similar to what Unity has for when "3D Gizmos" is enabled.

[Calinou]

We probably also want to have distance fade properties for gizmo icons, so that distant gizmos can be hidden to be less obtrusive (since their size is fixed).

Alternatively, we can make gizmo icon size depend on distance, but this will require a custom shader so that the size is kept to a reasonable value at its minimum size.

[LunaCapra]

I'm not sure how exactly the current gizmos are set up but this would probably also require sub-gizmos or additional handles positioned alongside the primary handles to take the scale into account as well.

The main example I could think of are the handles for a Path3D point.

[Calinou]

I'm not sure how exactly the current gizmos are set up but this would probably also require sub-gizmos or additional handles positioned alongside the primary handles to take the scale into account as well.

When drawing, each gizmo retrieves a material (example) generated in the constructor (example).

Here, EditorNode3DGizmoPlugin::create_handle_material() would have to be modified.

[LunaCapra]

I've been wondering, if there were more settings like you suggested - e.g. distance fade - where would these options go?
Currently there is View > Gizmos in the 3D editor to toggle individual Node gizmos.
But there is also Perspective > View Gizmos to turn them all of entirely.
There's also the entirely separate popup window under View > Settings, which seems to control the view camera rather than general view settings.

[LunaCapra]

I would like to note that it's been brought to my attention that there is a setting seemingly specific to the Android editor that does scale the gizmo handle size already.

Interface > Touchscreen > Scale Gizmo Handles

However, I do feel it would still be preferable to make this a general setting and expand upon it with the suggested distance fade and maybe other features.