32bit base set conversion project

The 32bit base set conversion project is a subproject of the 32bit Graphics Development project that aims to replace the 8bit Transport Tycoon Base graphics with 32bit equivalents.

It is our intention that eventually the game installer gives the user the option to download and install this graphics package as a base set, as an alternative to the original graphics and OpenGFX. Thus the graphics in it will be under tremendous public scrutiny. As a result, it will have to be controlled by stricter guidelines and individual entries into it will have stricter requirements for inclusion.


Graphics Requirements

32bit graphics project-wide guidelines

The suggestions here are mandatory for base set development.

Style, Visual Coherence

A somewhat uniform appearance of the base set is desired. This comprises lighting, color, detail props, ground textures and sprite edges. The graphics in TTD are crisp and clear with a high contrast. Vehicles use a lot of company colour.

We are aiming to reimplement OpenTTD in 32 bits per pixel - not to create a new game. Therefore we must protect the visual essence and feel of the original game world. This is an overall look that cannot be defined, but which must be achieved in order for an item to qualify for inclusion. The artist should pay attention to how their contribution fits in with the rest of the set.

GPLv2 or Compatible as License

OpenTTD is released under the GNU General Public License version 2. For clarity's sake, and to make it undisputably possible to bundle the replacement set with OpenTTD, it is mandatory for our graphics entries to be licensed under GPLv2 or a compatible license.

The GPL requires all software to be accompanied by their source:

3. You may copy and distribute the Program (or a work based on it, under Section 2) in object code or executable form under the terms of Sections 1 and 2 above provided that you also do one of the following:
a) Accompany it with the complete corresponding machine-readable source code, which must be distributed under the terms of Sections 1 and 2 above on a medium customarily used for software interchange; or,

[ ... ]

The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable.
If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code.

As you can see, the GPL wasn't exactly designed (therefore worded) for our kind of use. However, to comply with the license the best we can, and because it is a goal of this project for users to be able to make changes to the graphics, sources must be available in the graphics development file repository.

Sources include anything that makes it possible and easier to make modifications to all the sprites of the released entry. These can be:

Graphics Guidelines

Follow these guidelines and you should have a sprite that matches the rest of the set quite well.

Lighting, Shadows & Perspective

The sun is up high at around 4:30pm to 5pm. Objects are well-lit on all sides. Where there are shadows, they are sharp-edged and medium opacity.

The lightness of objects may vary depending on zoom level in order to make the game element easier for the player to recognise, thus making the game easier to play.

Like with 8bpp sprites, graphics use isometric projection with the camera at a 26 degree downward angle, with up in the game world being north.

We have template files available for (software) Blender, 3ds Max 3D Studio Max and 3D Lightwave. Ben Robbins has made a 3DSMax template and Aracirion a Lightwave template. You can pm them for details on each. For Blender, download version F, the new contrast version.


Like vanilla TT, our graphics have deep, vibrant colors and all colors are used. Where applicable, company colors are used brightly and clearly. Company colors rendered on models must match the colors in the color selector of the company properties window.

Standardised Props & Textures

Where applicable you should use a few standardized props: Props (New Graphics)

There are also a few textures for common materials: Standardised materials (New Graphics)


Scale is not a matter of colours used. The scale used by 8bpp sprites are applicable. This means that no common scale exists between different features and the same limitations apply as for all graphics, e.g. vehicles must not be longer than half a tile.

Scale may even be different for the length and the height of the very same object (train wagons are a good example of this).

Deliberate lack of national identity

In vanilla TT, the temperate climate is set in the British Isles, the home of game creator Chris Sawyer. The sub-tropical climate is set in Central South America and the sub-arctic climate possibly in Canada, northern Scandinavia or Eurasia.

Those locations are identified by distinct properties of landscape, nature and architecture, not by national or cultural symbols such as flags or writing.

We, while creating artwork, must also refrain from including such national or cultural fingerprints, while still retaining the look and feel of these locations.

Implementation and Distribution

When the base set replacement project is kicked off, individual entries will be released at the repository. Releases will be announced in the base set development thread. A call will be made which releases are included. Those will be flagged in the repository database.

While in alpha phase, the whitelisted releases will be read off the repository once per day and compiled into a single standard tar. Thus the set is playable via the tar route. These tars will be made available by Jupix at an undecided location, hotlinked from the forums.

In the final phase, when there are minimal gaps in the set, an actual base set will be compiled.

The releases will be distributed through the ingame content delivery system. Information on individual assets, including sources, will be available at the 32bit graphics development file repository.

Current Status

The base set project has not been kicked off yet.

See also