[Godot 4 beta 14 regression] Tilemap layer's modulate property has no effect when Tilemap and its layer's y-sort are both enabled

[SouthpawGoblin]

Godot version

v4.0.beta16.official [518b9e5]

System information

Windows 11, Forward+

Issue description

When a Tilemap and its layer's y-sort are both enabled, the layer's modulate property won't take effect.

If the layer's y-sort is disabled, the modulate property works fine.

And the problem extends to Tilemap's own modulate property of CanvasItem.

Steps to reproduce

1. add a Tilemap node to the scene, enable its y-sort property
2. add a layer to the Tilemap, draw some non-transparent tiles on the layer
3. modify the layer's modulate property, it'll take effect on the tiles
4. enable the layer's y-sort property, the modulate effects will vanish

Minimal reproduction project

N/A

[CarlCochet]

I think the bug appeared between Beta 13 and Beta 14. I have a project that works perfectly in Beta 13 and has this issue when I switch to 14+.

[therockerline]

I also have the same problem, the version is v4.0.beta14.official [28a2463]

[olibombardier]

I feel like I'm not familiar with the engine code to fix this issue yet, I tryed to understand how the tilemap rendering works but I'm not sure I understand. I might give it a try later.

By doing a bisect I at least found what commit caused the issue, maybe it will help somebody more familiar with the code: 10849a6d

[WilhelmT]

I have then same issue.

The problem only appears when using y_sort. Is there a workaround?

[mhaddy]

Issue still exists in 4.0.2 stable.