Add New Tileset

Summary

The file list you need to modify:
mod.yaml
rules/palettes.yaml
sequences/misc.yaml
And the structure sequences yaml file of each faction

You need to add the tileset yaml file into your tilesets folder

Example

Let's add a new tileset called "NEWTILESET"

1. Use Utility program to import the tileset if you have the tileset ini file:
   OpenRA.Utility.exe YOURMODID --tileset-import YOURTILESETINIFILE nte NEWTILESET
   PS: nte is your tileset file extension
   (You need to make a tileset if you don't have)
2. Copy the newtileset.yaml to your tilesets folder
3. Open your mod.yaml and find something like this:

TileSets:  
    YOURMODID|tilesets/temperat.yaml  
    YOURMODID|tilesets/snow.yaml  
    YOURMODID|tilesets/urban.yaml

Add a new line under the last tileset: YOURMODID|tilesets/newtileset.yaml 4. Open your palettes.yaml Add your new tileset reference to each section
PS: Make sure your palette file name is correct 5. Then open your 'sequences\misc.yaml'
Find the code like this:

target-valid-urban:  
    Start: 2

Add a new section after this:

target-valid-newtileset:  
    Start: 2

6. Now we need to add the new tileset reference to the structure sequence to make sure your structure can use the tileset
   to do this, you need to modify each structure sequence of each faction in your sequences folder

If you do these things above correctly, you will have a new tileset called NEWTILESET, then you can run the game and make a map by using this new tileset