What is the best way to draw this map in 3D

Hey

I am developing a space game which you play on other planets.

I right now have only a very basic mapping system which is essentially a grid and 3d objects randomly placed on it.
I now want to make a real map. For me it would be important that the mapping system is very stable and has a good performance. I like this engine and would like to adapt it for my 3D space game but different themed suggestions how i start with that:

 

What would be the difference between what you have now, and a "real map"?

 

There would be a bunch of differences let me go into detail from the things that are missing and i require.

For explanation i use a very cheap single big sprite as a background which is the main point where i say thats not a real map.

a) Right now there is no ground colouring. In the picture you have difference between stone and grass. I want to use like it does those things as resource too. I can add what a field is in the code but i have no idea how to display it.
b) Take those lakes right now i cannot do that.
c) My map is rather random i have no special choke holds or mountain ranges. I think however i can do this.
d) no tree collection also i think i can do this.

 

There is toms of tricks and simplications, when comes to map making. Simple colliders can indicate areas, like buildings lakes boundries, or forests, rather individual trees.

But to make such similar game more than just a grid, you want to learn about spatial mapping. And storing data in linear arrays, if you want get most of performance.

And of course, there I ECS.

 

Take it step by step. Instead of a big sprite as a background, use a bunch of little sprites (or even Unity's Tilemap support). Things like lakes etc. with rounded borders have been done for decades as tiles; google it and I'm sure you'll find many examples.

 

Actually that was my first idea but unity instantiate has too much overhead to use sprites directly it takes ages to render even small maps. i can try tilemap for this i did look into it but did not really finish there was a blocker so maybe i try again. For the tilemap what is the approach to make seamless borders in terrain?