I have a friend who has built this low poly triangle terrain, but when we go into play test mode, the edges of the terrain seem to be out of place. We have absolutely no idea why this happens or how to fix it.
This only appears on the client but not on the server (Also doesn’t appear when not in test mode).
All the parts are anchored too.
Client POV:
Server POV:
I’m not a builder, but you could try to anchor it or to weld it.
It is anchored. Although I should edit it to mention that.
I don’t really know, try to weld it, maybe it’s falling down somehow, or try to make a script that forces the thing to stay in that position.
Welding does absolutely nothing and neither does forcing the parts to stay in their position.
whats the point of welding it 
Which plugin are you using for triangle terrain? It could be the cause of your issue. Also one thing I’ve noticed with working on triangle terrain is that you have to select the edges in a pattern otherwise it would cause me weird glitches like a triangle being higher or lower than others so that could also be affecting your terrain.
This was the plugin used for the triangle terrain.
Give this plugin a try and let me know if you are having the same issue or something else.
https://www.roblox.com/library/495117212/Triangle-Tool-Node-Editor-INSPARE
Excuse me for the late reply, but we tried this plugin too and it has the same issues as the other one.
Try changing the collision fidelity to high on all the meshes.
Try putting them into a model then change their level of detail to StreamingMesh.
More info here
Update: Apparently I used the same plugin that me and my friend were having issues with, and I found out that the gap issues seem to lessen if the triangles are smaller. Don’t know why this happens, and I don’t know if anyone else has issues like these when making triangle terrain.
Hello.
The only other advice that I could give you is to ask the Developer of the Plugin (@Atrazine)
Although this could be cause of a certain setting, as I don’t have this problem. There is no other advice I could give on this, as I could just say try moving another part if possible to alling with it, but at a certain, as in all honesty I don’t use any Plugins and my creations turn out fine.
Sorry, I’m not help, but those are the only suggestions I have. 
