So In my custom SV that I use for my gameplay, I noticed there is a weird issue on some areas on the ground. I literally have no idea what causes this or how to resolve this but if anyone has any ideas I would love to try them out.
So as you can see in the pics the ground seems like it's being split into 2 and it can be very distracting (especially at night, or when it's raining and the ground gets wet.) This happens in quite a few locations throughout the world (but I didnt include them all since you can get the idea.) I tried removing the roads, repainting the terrain with a different texture, scultping the terrain but nothing works.
Thanks in advance!

Is it perhaps tiling in the texture? If you can see a pattern when you see it from afar.

Do those lighting differences follow the chunk boundaries perhaps?

@simsample Ok so I turned on the "Show Chunk Boundaries" option from the view menu and this is what I see. Some red and some blue, I never really paid attention to chunk boundaries, because I only edit premade worlds so I figured that there wouldn't be a problem there. But you are correct they do actually follow the chunk boundaries.

@Volvenom I don't see any pattern when zooming out...is there anything else I should try?

Hmmm, I'm not sure what you can do about the lighting issue if it's caused by the chunk shading- maybe try moving some lamps or using a lighting mod or custom colour ramps to minimise the effect. It's an artefact of the way the game works.

The blue chunks are those which have less than 8 different terrain paints used in them, the red ones are those which have more than 8 terrain paints. EA recommend keeping to less then 8 for best performance.

Everything I know about the way worlds are designed tells me that you're not going to be able to fix that. But SV is a well-designed world and the fact that there's no blatant issues with the lighting otherwise is a big plus.

Darn, this is bad news
I guess I'll try moving around some of the lamp posts to make the light flow better. Either way thanks for your help everyone!

You added terrain paints to exceed the 8? Do you have the problem only on borders where the chunk boundaries are red?

@daisylee Yes I did add an extra grass terrain paint (from the base game) and I only painted a small little area. The issue however appears on all borders both red and blue.

Have you tested the world in game? What is SV short for?

Perhaps you could try cleaning the global layer?

SV stands for Sunset Valley (the basegame world) and yeah I have tested it in-game. I could try cleaning the global layer, but will this remove the already populated sims in the world?

Yes, don't do it if you have got that far. Have someone else tested the world, perhaps you're the only one having these issues. Do you know when it happened, perhaps you can go back to a previous save.