Potential bug with Navigation2D and TileMaps?

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:bust_in_silhouette: Asked By scrubswithnosleeves

Hey All,
So I am using noise textures and a TileMap to generate random levels. black becomes collision tiles, white becomes empty tiles with navigation. Then I call the Navigation2DServer to get a path from the start to end point. ( I use the tilemap’s method update_dirty_quadrants() before the nav)
Completely randomly, the server will just return an empty path, even though there is clearly a reachable path. And if I re-run the TileMap generation and run it again within the same session, it fails again. In my code this creates a stack overflow and crashes.
Sometimes I have to run the script 20 times before it fails. Sometimes it happens twice in a row. Any ideas?
The code is pretty long, but Ill include the abridged version below:

noise = OpenSimplexNoise.new()
noise.seed = randi()
noise.octaves = 1
noise.period = 5.5

for x in range(1,  ROOM_SIZE.x):
    for y in range(ROOM_SIZE.y+1):
	var id = gen_id(noise.get_noise_2d(x, y)) # returns 0 or 1 depending on value
	set_cell(x, y, id)


var map = Navigation2DServer.get_maps()[0]
Navigation2DServer.map_force_update(map) # fails without this line
var path = Navigation2DServer.map_get_path(map, start_pos, end_pos, true)

This is a hard one to test but…

for x in range(1,  ROOM_SIZE.x):
    for y in range(ROOM_SIZE.y+1):    

This looks suspect to me. Are you intentionally skipping all the tiles in the first column range(1, ROOM_SIZE.x)?
Also are you intentionally including tiles outside the y boundary range(ROOM_SIZE.y+1)?

LeslieS | 2023-01-09 01:12