I'm sure Hitech will be along if I get any of this wrong.
The terrset you've referenced, with type0.bmp, type1.bmp, etc., was from the very earliest beta example release. You will want to start with the later released htcterrset.zip, probably already on your hard drive. The old zip files are no longer available, so we're waiting on htc to post the latest revision from the terrset update a couple of weeks back. Hopefully it will be edited into Hitech's Aces High Default Tiles post at the top of this forum.
I suspect you downloaded the htcterrset.zip file last year and it's on your hard drive, or at least the unzipped files are on your hard drive. That's a great place to begin as the textures will give you a good starting point. Modify or replace the textures you want changed.
The rest of this is meant to help others watching.
We must talk about file names and paths now.
Unless we hear otherwise, file naming conventions will probably still apply, 8 characters max for the master texture bitmap name.
When you open the default terrset folders (htcterrset.zip) and examine one of the atlas.txt files, you'll see that the htc file paths are embedded at the top of each text file. I'm going to make a leap here and suggest you don't have the same directory structure. Currently, the recommendation is to keep your custom terrsets together inside your terrain project folders. There are two choices to fix this file path issue, but I'll only discuss what's needed to follow the recommendation.
Edit all the atlas file paths for your target terrset as follows:
atlas,C:\art\ah2\stdtexnew\atlas\terrset00
512,ImageSize
Becomes
atlas,
512,ImageSize
This will force the OE/TE to look inside your terrain folder for the terrset folders and files.
The purpose of the atlas files has been covered elsewhere so I won't rehash it.
Suppose you have a germany terrain with the Euro terrset00, and you've made a copy of the project named germanyw. Copy the unzipped terrset00 folder into the terrain folder. When you open the new terrain, the textures inside the terrset00\texsrc folder will be installed. Currently, there will be no trees or building in your terrain because there were no .swa files shipped in those beta htcterrset.zip files. The clutter and detail will be there, but no trees. You can add trees and buildings later.
Edit the textures in PS or GIMP. If you're creating new textures with new names, be sure to edit the entries in the appropriate atlas.
I always remove any dot htx, dot sta, and dot stb files created by the TE in the terrset0x folder as they would override my new texture changes in the past.
When you reopened the terrain in the TE and set the tile set to match your custom terrset, you should see the ground textures called for in the atlas. If it fails to install the texture, or worse, check your atlas, and then check that the bitmaps are at the appropriate bit depths etc. I will usually leave the default textures and only modify one at a time.
On my FE, as I've said, the clutter is there but the .swa file and its trees and buildings are missing.
Save your terrain. When your texture(s) is finished and working, install your trees and buildings with the OE.
Open your target texture in the OE, using the primary bitmap for the tile.
The OE will spit an unhelpful error if the terrset folder number doesn't match the terrset you've set in the tiles Properties dialog of the OE, Euro for 00 etc. As soon as these two match, you'll see the texture.
It will cover a 2x2 mile surface.
The only speedtree objects listed for installation will be those from the correct terrset.
Add a tree or two and save. This will create the .swa file for this tile, [tilename].swa, in your terrain. Without that file, things can go badly, as in invisible objects, dropped objects, etc. Close and reopen the tile and continue.
When done, the TE will make binary versions of the .swa files with the extension .swb. Until that conversion happens, you won't see the trees in the TE or in the game.
