Not all lake edges smooth into shallow water

[Xpyder]

Part of the river spawned isolated with only one half of the tiles
It's about even with the lower bend, just to the right of the forest.

[Mecares]

Looks like a oxbow lake a natural result of meandering rivers.

[Xpyder]

If it was intentional then it should have shallow tiles all around it, it wouldn't go from deep to land.

Also I thought lake tiles had their own notation, or is that only ponds?

[edit] I see what you did there. 'cause an oxbow is part of a lake that got cut off. Heh 😄

[vache]

If I recall correctly, it is actually an overmap special that makes these. They're supposed to be something like ponds, but the generation doesn't usually place enough tiles, and the river smoothing algorithm doesn't know how to handle them so they often end up looking disjointed and awkward.

[Xpyder]

could be. It looks almost like it and the forest were placed, then overwritten by something else, but the river's on the other side so either way there's a bug somewhere.

[vache]

It's not supposed to be connected to the main river:
https://github.com/CleverRaven/Cataclysm-DDA/blob/master/data/json/overmap_specials.json#L14

It's supposed to generate as a blob of "river" to simulate a lake, but the blob shape is too sparse and it doesn't generate as "connected" as it should be for the smoothing to take effect.

[Leland]

Alright so just to recap – this issue is about lakes, which use river tiles and spawn without a connecting river.

The game's river "smoothing" applies to deep water and introduces shallow water on the edges. You'd expect it on lakes as well, but, like @vache said, the lakes' river tiles are too small and too far apart to get smoothing applied.

IMO, I think the issue is really two-fold:

1. The edges aren't shallow, like mentioned, and
2. The tiles for rivers and lakes are exactly the same.

I don't think very many people, including myself, knew that these were supposed to be lakes. They just look like mapgen screwed up the placement of rivers.

One possible solution could be just only doing shallow water in lakes but I don't think our mapgen supports that currently.

[kevingranade]

Also still water and flowing water can be expected to have different properties (freshness, swim difficulty, population of animals)

[Leland]

#21833 encountered this issue (as well as some oddness in the shape of the lake)

[ralreegorganon]

As of #30442 these lakes that were created by dropping a few river tiles on the map no longer exist and have been superseded by dedicated lake mapgen.