Try this:
Even if you have a Perspective Camera
, attach a small script to your camera, and set the camera's .transparencySortMode
to TransparencySortMode.Orthographic
. You can probably do this in Awake
or Start
.
(You can also let some kind of manager do this for you. I actually don't know if this setting serializes into the scene/prefab.)
What this does is make it sort renderables according to flat-plane-distance instead of actual diagonal distance from the camera point.
Let us know if this solution works for you!