Terrain Creation Guide
From Worms Knowledge Base
Contents
Background and Prerequisites
This guide will explain how to create your own custom terrains which you can then play just as you would other randomly-generated terrains such as Forest, Cheese etc. See the wkTerrainSync page for more info on how to play additional terrains. wkTerrainSync is a module that allows you to play additional terrains offline and in online multiplayer.
A terrain comprises the background elements (the sky colour gradient, the mountains and falling debris), a repeating land texture and soil texture (revealed when terrain is destroyed), the grass textures (for the upper and lower parts of the terrain), the bridge (comprising a left, middle and right part) and up to 32 custom objects to be placed randomly. These objects can be configured to appear on the floor, ceiling or side of the terrain.
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 files 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 (SpriteEditor.exe) is able to take your image assets (in .BMP [Indexed palette, 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 may not 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: 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.
Check out the EasyTerrain Utility which allows you to use a template image containing all of your image assets to automatically create the files necessary for Sprite Editor to create a terrain.
Core Files (required)
| File Name | Info |
|---|---|
| text.img | The main texture of your terrain. Dimensions: 256 x 256 |
| soil.img | The soil texture revealed when land is destroyed. Dimensions: 256 x 256 |
| back.spr | The background mountains image. Dimensions: 640 x 160. Despite being an .SPR file, this is a single image and the background cannot be animated. |
| back.spd | The sprite parameters file for back.spr. Edit width/height parameters as necessary. |
| bridge.img | The flat part of the bridge. Dimensions: 64 pixels wide, variable height. |
| bridge-l.img | The left part of the bridge. Dimensions: 64 pixels wide, variable height. |
| bridge-r.img | The right part of the bridge. Dimensions: 64 pixels wide, variable height. |
| debris.spr | This is the animated falling debris. It's a single image containing all of the animation frames stacked vertically. Dimensions vary depending on content. |
| debris.spd | The parameters file for debris.spr. Adjust frame width, height and number of frames accordingly. 'framerate' should be 0. 'flags' should be 1. |
| gradient.img | The sky gradient image. Dimensions: 8 x 916. This is the only image asset to have its own 17-colour palette (not shared with other assets). All other assets share up to 97 colours. |
| grass.img | Contains the top and bottom terrain grass and the edge colour you see when objects and land are destroyed. Open the example grass.img.bmp to see how this is divided up. Width is 136 pixels. Height is variable (typically around 16 pixels in stock terrains). |
| Index.txt | A list of the custom object filenames to be used on the terrain (excluding the above assets). No file extensions. Maximum of 32 objects. See 'Custom Object Files' below. |
| Level.dir.txt | This is used by SpriteEditor.exe to compile the final Level.dir file. It's a simple list of all files to include. NOTE: .SPD files are not included. The utility uses the .SPD and .BMP to create the .SPR file |
NOTE: For convenience, there's a '_UPDATE INDEX AND LEVEL.DIR FILES.bat' script in the EXAMPLE TERRAIN folder. When all of your files have been created, run this to automatically build the 'index.txt' and 'Level.dir.txt' before compiling the final Level.dir file.
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, ceiling and side.
Your objects can have any file name but the name must end with '.img.bmp' (including file extension). EG, toaster.img.bmp. 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-ceiling-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 :
| eg_value | Info |
|---|---|
| 5 | Can be 1 to 10. This value affects the chance of an object being placed and is relative to the values of other objects. EG, by setting all objects to 5, you can increase or decrease the values for objects that appear too little or too much (smaller objects or objects with a narrow base will typically have more places to appear in the terrain) |
| 0 | Specifies whether the object is in front or behind the terrain. 0 = behind, 1 = in front |
| 0 | Specifies whether the soil texture appears when the object is destroyed. 0 = none, 1 = soil |
| 1 | Enables or disables collision for the object. 1 = enabled. 0 = disabled |
| 1 | Specifies whether other custom objects can be placed onto this one. 0 = Yes, 1 = No |
| 3 | Location type of object. 0/1 = side of the terrain, 2 = ceiling, 3 = floor (0 or 1 indicate which side of your object is to be fixed to the side of the terrain, left [0] or right [1]) |
Custom object dimensions can vary but the height and width values must be divisible by 4 if you wish to use .IMG compression in Sprite Editor (recommended as this reduces file size significantly). If dimensions aren't divisible by 4 and you have IMG compression enabled, the object will appear corrupt in-game likely due to a bug in Sprite Editor.
All images must be saved in BMP (Indexed palette, OS/2) format for SpriteEditor to convert, or you'll get an error.
Palette
Worms uses indexed palettes for all assets. The first colour represents transparency and must be the same for all assets used. This colour could be used to put holes in your object for example.
All core and custom object image files, apart from 'gradient.img.bmp', must not take up more than 97 colours in total (including the 1st colour used for transparency). It is recommended to index all of these assets down to the same 97 colour palette [check out the video links at the bottom of this guide].
'gradient.img.bmp' has its own 17 colour palette (as always, the first must be set to the transparency colour used for all other objects).
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 - UNCHECK the "Compress .SPR files" and "Opaque .IMGs" options (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 - UNCHECK the "Compress .SPR files" and "Opaque .IMGs" options (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
SpriteEditor.exe can be used to extract assets from existing level.dir files, including the default terrains created by Team 17.
- 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 have problems extracting from level.dir's that the utility creates. It seems to extract fine from the default level.dir files created by Team 17.
Custom Terrain Water Colour
The wkTerrainSync module supports loading an alternate 'Water.dir' file for your terrain allowing you to customise the water colour.
Use the Water Colour Editor v2 utility to create the new 'Water.dir' file for your terrain. This is a modified version of Water_color_editor that supports the smoother water animation introduced in 3.8. Once you're happy with how the water looks in the utility, simply save the new 'Water.dir' file inside your terrain directory (alongside the Level.dir and TEXT.img files).
Tips and Tutorials
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 edge colour held in 'grass.img' that is revealed as terrain and objects are damaged. This 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.
It's generally best to avoid text on objects. The game randomly flips objects horizontally so there's a 50/50 chance of it being readable.
VIDEO: How to create a sky gradient in Photoshop and index down to 17 colours.
