Xray/selecting through faces (UI inconsistency, UX issue)

I’ve been using 2.8 for some time and I noticed a confusing inconsistency.

In previous versions shift+z and z was used to switch between draw modes. But for modelling I, and likely many other people, used z to switch between wireframe(xray/selectthrough) and solid view. It was essentially a toggle button.

With new display modes I have noticed that each has the see through mode, which is activated with this button in edit mode. (Middle of the image, cube with 4 dots)

So we can use Z to switch through shading modes…
…but once we reach Solid shading mode and press Z one more time the above button will be activated (even though it’s not a shading mode since it’s a toggle in each mode.)

It is also not clear to me how the Xray slider works and the purpose of it, since it doesn’t allow clickthrough. It seems it’s connected to the first button pictured above, controlling the face opacity, but that button is not called Xray. Also enabling Xray removes the other button
which caused total confusion for me because the button is present in other modes but not in Solid anymore until deactivating Xray.

ISSUE: the shortcut that activates the clickthrough button is the same that activates Solid mode. The tooltip for the button isn’t named Xray toggle, which is what it actually is. Toggling the Xray checkbox in the Shading expandable makes the button disappear, but only in Solid mode.

SUGGESTED SOLUTION: Adding a shortcut for toggling the xray button. Adding “X-Ray toggle” to the button tooltip. Removing the xray checkmark in the Shading expandable and renaming it to “X-Ray opacity”.

Thank you for reading. I have waited a while to see if this will be discussed as it seems like a pretty big UI inconsistency which had me confused and figuring out the logic of it.

In 2.79, Z is used to switch between a wireframe mode and solid one.
From developers point of view, wireframes become overlays in 2.8.
I think that because it was internally different, they thought that would be pertinent to reflect it in UI and get rid of wireframe mode.

This move let Z shortcut free to be used for something else.
So, it was used for something else that exists in 2.79 and was close: toggle between selection limited to visible elements on front of mesh \ selection unlimited with visible elements of back of mesh by seeing through mesh.

Then, seeing through the whole scene was added. And for consistency, same shortcut used to see through mesh in edit mode was used to see through in object mode.
And you are totally right, it ended up with an incoherence.
Same shortcut for 2 different things. Blender allows that. Same shortcut can be used for different things in different contexts.
Problem is that is same context, here.

Mistake is that X-ray overlay is not dependent of the mode. Limitation of selection is dependent of mode.
It means that X-ray toggle by using Z is not working in edit mode. In this mode, it is “limit selection to visible” toggle that have priority.
So, user cannot set the whole scene X-ray transparent if active mode is edit mode, just transparency of edited mesh.
On the contrary, user cannot set the scene solid or just the edited mesh if X-ray was activated before entering Edit mode.

It is right. Having one shortcut per option will solve the problem.
Another solution could be to remove Limit to Visible selection option. It is probably the decision made.
Currently, it only has an impact on vertices selection of masking in Weight Paint mode.
All its advantages for paint modes have been transferred to Brush properties.
But if nobody is annoyed by behaviour in edit mode.
Same behaviour in Weight Paint mode should not be problematic.
And nowadays, old per object X-Ray option have been restored. So, armatures can be visible through a solid mesh without global X-ray of scene.

The Xray slider is here to switch between the old wireframe mode situation (0) to futurely abandoned “limit to visible” situation (1).
It is not really practical to use a slider for that.
So, proposal was made to let users create presets for display.

To sum-up,in practice, 2.8 should provide shortcuts, a pie-menu to switch into different display situations. In practice, same ones as the ones present in 2.79. But by using different theoretical concepts.
And currently, what is in place is unsatisfying and confusing because it corresponds to an intermediate state.

Yes, we should fix this.