Question SetTile() taking UNGODLY processing power.

I'm making a sim game where players can edit terrain in real time, with mouse clicks. The world is 1000 X 500 tiles. There's a tilemap for rock and another for sand; both have Tilemap Collider 2D and Composite Collider 2D for automated physics.

Recently I added this piece of code:

if (tile == (int)Manager.Tiles.Erase)
{

manager.RockTiles.SetTile(temp2, null);
manager.SandTiles.SetTile(temp2, null);

}
else if (tile == (int)Manager.Tiles.Rock)
{

manager.RockTiles.SetTile(temp2, manager.Rock);
manager.SandTiles.SetTile(temp2, null);

}
else if (tile == (int)Manager.Tiles.Sand)
{

manager.RockTiles.SetTile(temp2, null);
manager.SandTiles.SetTile(temp2, manager.Sand);

}

Every time the player clicks on the world to add or erase a new tile, the game literally pauses for several seconds. The profiler is accusing frames taking 6 SECONDS and the offending functions appear to be Tilemap based, namely recalculating the geometry of the Composite Collider 2D.

Is this normal/expected? Am I implementing this wrong? Is there any workaround for this?

 

you need to split the tilemaps into chunks(32x32 for example), the problem is that everytime you set tile the collider is recalculating new shape collisions for your huge tilemap( insane cpu cost )

 

Zeroing the Offset Distance has improved performance considerably; still a few orders of magnitude short of a workable solution, of course. I haven't yet attempted dividing the large tilemaps into multiple smaller ones as that will involve a fair bit of scripting.