GridMap Mesh Library "Clear" doesn't actually clear the grid-map

[Alastor01]

Godot version: 3.0, 3.1, 3.2

OS/device including version: Windows 10 Pro 64-bit

Issue description:

• GridMap inspector has a section for choosing Mesh Library
• In this section, you can "Clear" currently assigned Mesh Library, which removes the Mesh Library and (apparently) deletes all tiles
• But this is not true, because even if you restart Godot, and then attach the same Mesh Library, all your tiles will be there at the scene again
• Clear implies complete removal of data, so this is not how it is meant to work. That is, by clicking "Clear", it should remove all history as well so you can effectively clean your map.

Steps to reproduce:

1. Add a Spatial, add a GridMap as its child
2. Assign your Mesh Library to the GridMap
3. Dump a couple of tiles, save, now use "Clear", see your tiles disappearing, save
4. Restart Godot, open your scene, re-add the Mesh Library and find your old tiles to be at the scene again

[simpuid]

Confirmed it on x11.
Looks like the clear only clears the Mesh Library reference not the actual grid map data.
Also, what should be the intended behavior if we change the Mesh Library with different one? It should clear the grid map or not?

[Alastor01]

Also, what should be the intended behavior if we change the Mesh Library with different one? It should clear the grid map or not?

@simpuid This is a good question. In most cases you would want to clear the grid map. Say you have an updated Mesh Library. Most likely it will have either new tiles that old one does not have or missing old tiles. In this case the tiles will not have compatible IDs and your map will become a mess.

[Kakcalu13]

This issue occured to me as well too (I'm using 3.4). Any update on this one?

[Calinou]

This issue occured to me as well too (I'm using 3.4). Any update on this one?

#37136 closes this issue, but it may not be desired behavior as per discussion in that PR.