Hello atmadaenygma
Q: Is there a way to double the map size (from 8 km to 16 or even 32km)
A: according to my tests you can have in a single map about 20 by 20 km where everything works. Things that are further away render properly but some problems withe the floating point precisions and the distance to the world origin start to happen.
You can put as many height map based landscapes in to your map if you like to get a bigger game world without loosing details, otherwise you can juts change the scale of the landscape.
However there is a limit for the build process of 2 GB of data per map file. This can become problematic if you like to have a filled huge world with 20 by 20 km in a single map file.
The solution is most likely for you to use the World Composition system that allows you to build a gigantic map out of good to handle sub maps see this link.
Q: different things 1. beach 2. swampy area with inner islands, 3. 1 port town and one small town with many dispersed villages.
The material system is automatic and dynamic hence you can use it on any landscape and it also works with all landscapes that you build your self not only those that are include in the package.
However you can only have one automatic and dynamic material system per landscape with a good performance. I would recommend to use multiple landscapes in the map If you need locations with a completely different look and adjust the settings accordingly so that each of them has a separate materiel instance of the procedural material.
The system will also work seamless across multiple landscapes if both have the same material on them and the points where they intersect are in the same place and not to different withe there vertex normal.
Q: For that reason I really like the map 4 (down)-3 (over)
You don’t have to chose just one you can have multiple height map based landscapes, you are also not restricted to what is in the pack you can build and add your own height maps. It is worth mentioning that you can import and export landscape maps out of the editor as RAW files. This is useful if you like to backup things or use, save or edit them outside of the editor. You can even combine them using an image editing software. You can use all things in the packs in any way you like, I would recommend to use the maps as starting points and adjust them to what you need if you like one of them and need a quick result. I created the maps with attention to detail but its up to you to edit them for your “small town” and other locations and adjust things to fit your game.
As a side note see Landscape Splines to build roads and pathways and so on:
the water was really an uplifting!
