Descriptive Problem Summary:
I have alot of stuff on my map, and also alot of open multi-z enviroments that are rendered using vis_contents per individual open space turf, when a turf below open space tile is also an open space they form this recursive chain that lets us see on the lowest possible turf, and i use this alot, half of the map is like that.

It seems that perhaps i somehow hit a limit of how many things client can render? Which leads to these very weird and random artifacts all over the place.

Here's how it looks in motion: https://cdn.discordapp.com/attachments/382276327614447647/ 1360570196129218710/2025-04-12_13-59-50.mov?ex=6800df3c&is=6 7ff8dbc&hm=beb4cf19431b100873bbae9de8cea2c7853e4c320291b6982 2d471b0932e375e&

My first instinct was to confirm whenever its a problem specific to my code or is it byond that fails to do this, so i switched to 514, here is the video:
https://cdn.discordapp.com/attachments/382276327614447647/ 1360583397050679436/2025-04-12_14-52-24.mov?ex=6800eb88&is=6 7ff9a08&hm=d61909bf4cc219d95c57e7ae1e67c540299dc9758b3cce328 fad746e25dfc7cd&
As i thought it wasn't occuring on 514 byond.

P.S. Videos look like that because i turned off all plane_master logic to ensure its not my plane_master behaviour doing that.

Numbered Steps to Reproduce Problem:
I wasn't able to reproduce these artifacts on a clean project with just turfs and open spaces unfortunately, I would gladly help to assemble it if there are ideas on how to.

Expected Results:
Here's the part of the map with all vis contents turned off on the map:
https://media.discordapp.net/attachments/ 1228611598554370080/1362045551826309121/ image.png?ex=6800f745&is=67ffa5c5&hm=3d12a6647e17ead6f431386 052250be25733418f0df2f0c14e5f3ecd36e8840c&=&format=webp&qual ity=lossless

Actual Results:
Same part of the map but with all vis contents on the map turned on:
https://media.discordapp.net/attachments/ 1228611598554370080/1362045434259964055/ image.png?ex=6800f729&is=67ffa5a9&hm=8e8dd6b80f7d2dbc3f389eb 7d574ecf5b6b8ddf659bbb8c6a95184d5c0e2450f&=&format=webp&qual ity=lossless

Does the problem occur:
Every time? Or how often?
Consistently, every time.
In other games?
Can't confirm
In other user accounts?
Yes.
On other computers?
Yes.

When does the problem NOT occur?
The less turfs on the map use vis contents the less artifacts i can find on the map.

Did the problem NOT occur in any earlier versions? If so, what was the last version that worked? (Visit http://www.byond.com/download/build to download old versions for testing.)

I searched for the specific version this issue starts to occur at, and i found that 515.1615 version is the first one where the issue starts to occur, with nothing of sorts occuring before it. And yes, it still occurs on any 516 version.

Workarounds:
Increase of x size of the map shifts all visual artifacts to the right.
Increase of y size of the map shifts all visuals artifacts vertically up.
Increase of z size of the map makes artifacts go up a z-level.
Turning off vis contents on the map makes artifacts disappear.
Cutting amount of vis contents on the map by 1/5 made artifacts cease to appear as well.

Is this enough information or testbed is still critical to solving this?
What else can i help with in order to figure this out? Provided i am not yet able to reproduce it on a clean project?