Difference between revisions of "Terrain Creation Guide"

Revision as of 14:54, 1 January 2021

[This page is a work in progress. New tools are in development that will likely replace Sprite Editor]

Background and Prerequisites

This guide will explain how to create your own terrain files using the WA Directory Editor utility (SpriteEditor.exe). You can then play your terrain just as you would other in-game terrains such as Forest, Cheese etc.

See the wkTerrain page for more info on how to play additional terrains.

Terrains are stored under the DATA\Level folder of your Worms install directory. Each terrain has its own folder containing 2 files: 'Level.dir' and 'TEXT.img'.

'TEXT.img' is a small icon representing the terrain in the in-game land generator. 'Level.dir' is an archive file (similar to a zip) that contains all of the terrain images and config files.

The image assets in Level.dir are in two formats that you can't edit directly; .IMG files for images, .SPR files for animated sprites. .SPR files are accompanied by a .SPD text file containing parameters for the .SPR file (frames, width, height etc).

The WA Directory Editor utility (https://worms2d.info/WA_directory_editor) (SpriteEditor.exe) is able to take your image assets (in .BMP [OS/2] format), convert them to .IMG/.SPR and then produce a Level.dir file usable in the game. It is also able to extract assets from existing level.dir files although the program is a bit buggy and some files wont extract.

Sprite Editor converts your BMP files to .IMG/.SPR files based on the filename. EG, 'soil.img.bmp' will convert to the IMG file 'soil.img'. 'debris.spr.bmp' will convert to the .SPR file 'debris.spr'.

Download and extract these terrain guide files to help you get started: https://www.tus-wa.com/files/file-2229 This has an 'EXAMPLE TERRAIN' folder containing examples of the core assets required for all terrains and 4 example custom objects. It also contains the standalone SpriteEditor.exe for convenience or you can download it from the link above.

Core Files (required)

NOTE: For conveniance, there's a '_UPDATE INDEX AND LEVEL.DIR FILES.bat' script in the EXAMPLE TERRAIN folder which will automatically build the 'index.txt' and 'Level.dir.txt' files including your custom objects as you create them.

Custom Object Files

You need at least 1 object for the terrain to work and can have a maximum of 32 objects (excluding the core objects above).

There are 3 types of object placement in the game; floor, roof and side.

Your objects can have any file name but the name must end with '.img.bmp' (including file extension). EG, toaster.img.bmp. It's recommended to avoid spaces in the file name and if making a lot of objects it's a good idea to name them based on object type, eg, 'obj-floor-toaster.img.bmp', 'obj-roof-knife.img.bmp', 'obj-side-fork.img.bmp'.

Each custom object you create must be accompanied by an .INF file. EG, the object 'obj-floor-toaster.img.bmp' would have the .INF file 'obj-floor-toaster.inf'

The INF file contains a list of numbers representing internal parameters that describe the properties of your object, EG:

5
0
0
1
1
3

In order, this is what the values represent for each line :

Custom object dimensions can vary but the height and width values must be divisible by 4. This allows .IMG compression to be set in Sprite Editor reducing file size significantly. If dimensions aren't divisible by 4 and you have IMG compression enabled, the object will appear corrupt in-game.

All images must be saved in BMP (OS/2) format for SpriteEditor to convert, or you'll get an error.

Palette

Worms uses indexed palettes for all assets. The first colour must be black in all palettes to represent transparency.

All core and custom object image files, apart from 'gradient.img.bmp', must not take up more than 97 colours (including black for the 1st colour). It is recommended to index all of these assets down to the same 97 colour palette.

'gradient.img.bmp' has its own 17 colour palette (as always, the first must be black).

Creating the Level.dir File

When all of your BMP objects are saved, and all .INF and .SPD files have been created/updated, update the 'Index.txt' and 'Level.dir.txt' files either manually or by running the script.

You're then ready to create the final Level.dir file :

- Open SpriteEditor.exe
- Ensure "Compress .SPR files" and "Opaque .IMGs" are UNCHECKED (they are checked by default).
- Select "Reconstruct from log"
- Select your 'Level.dir.txt' file.
- The utility will convert all of your BMP assets into IMG's and .SPR's
- Select "Save-As" and save the file as Level.dir

Creating the Terrain Icon (TEXT.img)

This is stored in the TEXT.img file that accompanies your Level.dir file. It must be 64 x 64 and 17 colours (first colour black).

- In the ICON folder within the "EXAMPLE TERRAIN" folder you'll see an example 'TEXT.img.bmp' file. Save your icon with this file name.
- Open SpriteEditor.exe 
- Ensure "Compress .SPR files" and "Opaque .IMGs" are UNCHECKED (they are checked by default).
- Select "Reconstruct from log"
- Open the "icon.txt" file in the ICON folder. This will immediately create the corresponding TEXT.img file. 
- Close SpriteEditor

You now have the Level.dir and TEXT.img files for your terrain. Create a subfolder within 'DATA\Level' giving it the name of your terrain and copy over the 2 files. You can now play the terrain.

Extracting Assets from an existing Level.dir file

- Open SpriteEditor.exe
- Select Open and navigate to a Level.dir file
- Select 'Extract, convert, log' and select a folder to extract the contents to.
- You may also select individual assets to extract.
- The utility is buggy/incomplete, you may not be able to extract some files

Tips

For better playability, ensure the terrain texture (text.img) can be easily distinguished from the background (back.spr) and the soil texture (soil.img). Also check the 'fringe' colour held in 'grass.img' that is revealed as terrain and objects are damaged. This also needs to be distinguishable from the background and soil, particularly as the terrain gets destroyed leaving tiny bits of land, sometimes individual pixels.

If you find an object always appears too low (embedded) in the terrain, try increasing the height of the object canvas slightly (not the object itself), adding more transparency at the bottom of the image. By increasing further you can make objects appear off the ground.

If using Photoshop to create the sky gradient, when indexing down to 17 colours use the 'Pattern' dither rather than 'Diffusion' dither, it produces smoother results.