Awesome Butterfly Swarm Biome - Broken?

[RandomFace 5]

I recently stumbled upon the JungleFlower biome in shipwrecked for the first time (I had no idea it existed until now). The biome is covered in flowers and spawns large swarms of butterflies as can be seen in the attachment.

The weird thing about this biome is the way spawning works. The butterflies only spawn in large amounts if:

• You save a game within the biome and then load the save... Or save close by and run there before the first butterflies start spawning.

• The first day of monsoon when butterflies begin spawning again according to this.

If you remain in the biome after a swarm and wait for the next day, butterflies will begin spawning normally (no swarm). If you load the game a few screens away from the biome and wait for a butterfly to spawn, then run to the JungleFlower biome, butterflies will be spawning in small numbers (no swarm).

I'm wondering if this is intended behaviour or whether the biome is meant to always produce lots of butterflies but somehow the spawner settings are being overwritten/ignored. Maybe the world butterfly spawner prevents the biome specific spawners from working?

The files that seem to be involved are:

terrain_jungle.lua which adds the room "JungleFlower" and in doing so creates 6 butterfly_areaspawner.

butterfly_areaspawner.lua which creates the butterfly spawners with settings: followplayer = false and SpawnModeVeryHeavy()

butterflyspawner.lua where the spawning happens

Any bored klei developer or forum lua expert share their thoughts? I may try to add a fix if it's caused by a bug (ignore pun).

Edited December 4 by RandomFace

[TheUnforgivingBR 17]

It's a setpiece, just like Mushroom Island.

Edited December 5 by TheUnforgivingBR

[RandomFace 5]

I'm aware it's been added purposely, I just can't find code that says "only spawn a swarm of butterflies once per game load". It seem's almost accidental that butterflies don't spawn in large numbers each day in the JungleFlower area.