Collision exceptions don't work with TileMap node

[nmearl]

Godot version:
v3.0.1.stable.official

OS/device including version:
elementary OS 0.4.1 Loki
Ubuntu 16.04.3 LTS
Linux 4.13.0-36-generic

Issue description:
Using the add_collision_exception_with method of a KinematicBody2D when the other Node is a TileMap does not result in collisions being excepted.

Expected behavior that KinematicBody2D falls through TileMap.

Steps to reproduce:

• Generate Tileset from scene with hierarchy

+ Node2D
  + Sprite
    + StaticBody2D
      - CollisionPolygon2D

• Create new scene with a TileMap and KinematicBody2D.
• Add Tileset to TileMap and create a platform for the KinematicBody2D.
• On key event, attempt to add collision exception between TileMap and KinematicBody2D using add_collision_exception_with(get_node("../TileMap"))

[davi2205]

I have the same problem :/

[KoBeWi]

Still valid in 07db4d5

Here's MRP:
ReproductionProject.zip

EDIT:
For the record, this is also an issue with raycasts: #22891

[jakefriend-dev]

For anyone coming across this and looking for a mid-term solution for raycasting past a TileMap, I worked around this with a process of replacing TileMap-based exception addds with shifting the Raycast2D along its own length, then shortening the length.

So, instead of adding an exception, the Raycast2D is moved along its length by a set increment (and shortened, so that the initial distance doesn't get extended). You continue to loop as if there's an exception, and eventually you'll either get past the TileMap collision, see something else, or run out of length to increment. Seems to work fine in practice! You do need to remember to reset the raycast's length at the start of your loop.

[knightofiam]

Confirming issue still exists in 3.5 stable with RayCast2D.

[knightofiam]

For anyone coming across this and looking for a mid-term solution for raycasting past a TileMap, I worked around this with a process of replacing TileMap-based exception addds with shifting the Raycast2D along its own length, then shortening the length.

So, instead of adding an exception, the Raycast2D is moved along its length by a set increment (and shortened, so that the initial distance doesn't get extended). You continue to loop as if there's an exception, and eventually you'll either get past the TileMap collision, see something else, or run out of length to increment. Seems to work fine in practice! You do need to remember to reset the raycast's length at the start of your loop.

There's a simpler TileMap workaround in case you're looping RayCast2D collisions multiple times per frame to get all of them instead of just the first one it hits:

1. In the loop, check if the collision object is a TileMap and if so add it manually to a custom list of TileMap exceptions.

2. Each iteration check if the collision object is both a TileMap and in the exception list and if so ignore it.

3. Force the raycast to update in the same frame using RayCast2D#ForceRaycastUpdate.

(Don't forget to clear the exception list first, outside the loop.)

You can see my full working code for this here.

[akien-mga]

Closed by #73851.