Transparent Sprite3D occludes 3D gizmo icon that should always be drawn on top

[yikescloud]

Godot version:
3.3 RC 6, 3.2.2 official

OS/device including version:
windows 10

Issue description:
Sprite3d with transparent flag on always keep front on the screen, and it will hide the gizmo icon
This image shows the issue, the sprite3d actually behind the light

Left is the transparent, right is without transparent

Minimal Reproduce
GizmoBug.zip

[yikescloud]

And I found that if you change the editor camera fov to a smaller value(15 degrees), the gizmo icon will become incredible size

[yikescloud]

Seems like turn alpha-cut to discard will fix this, but that will cause the image outline jagged and looks bad

[Calinou]

And I found that if you change the editor camera fov to a smaller value(15 degrees), the gizmo icon will become incredible size

This is expected, since you are further zoomed in yet the gizmo remains of a fixed size. We need to find a solution that doesn't involve adding too many settings that people must constantly tweak. I suppose adjusting gizmo size to be smaller when using a lower FOV could work, but this won't solve the other 3D gizmo visibility issues we currently have.

Seems like turn alpha-cut to discard will fix this, but that will cause the image outline jagged and looks bad

This is because using alpha testing instead of alpha blending avoids issues related to transparency sorting. The downside is that its hard edges can't be smoothed out by MSAA (but they can still be smoothed out by screen-space antialiasing algorithms like FXAA, which will be available in 3.3).

[yikescloud]

And I found that if you change the editor camera fov to a smaller value(15 degrees), the gizmo icon will become incredible size

This is expected, since you are further zoomed in yet the gizmo remains of a fixed size. We need to find a solution that doesn't involve adding too many settings that people must constantly tweak. I suppose adjusting gizmo size to be smaller when using a lower FOV could work, but this won't solve the other 3D gizmo visibility issues we currently have.

Seems like turn alpha-cut to discard will fix this, but that will cause the image outline jagged and looks bad

This is because using alpha testing instead of alpha blending avoids issues related to transparency sorting. The downside is that its hard edges can't be smoothed out by MSAA (but they can still be smoothed out by screen-space antialiasing algorithms like FXAA, which will be available in 3.3).

You're right, I change the sprite3D to Mesh and set the render priority to -128, it fix, though the 3d axis and grid show always above. Seems the gizmo has different render priority

[KoBeWi]

Looks related to #24069

[Calinou]

Thanks for the report! Consolidating in #24069, as this is due to the same cause.