The game resources as well as the mod resources consist of code files (scripts, configurations, …), 3D files, texture files and soundfiles. This page describes the structure of the most common ones.

A lot of information is stored in code files. Code files in Transport Fever 2 usually use the following file extensions:

• .lua for scripts
• .lua for configurations
• .con for constructions
• .vs / .fs for shaders

Script files usually return a struct with several functions that can be imported and used from elsewhere:

local scriptstruct = { }
 
function scriptstruct.functionname1(parameter1, ...)
  -- function code
end
...
 
return scriptstruct

Most of these files can be found in the res/scripts/ directory. See the documentation of script modding for further details.

Configurational files usually consist at least of the data() function that can be retrieved from elsewhere:

function data()
return {
  -- content of data struct depending on type of configuration
}
end

Most of these files can be found in the res/config/ directory.

Constructions use the file ending .con but basically their internal structure is similar to configurational files:

function data()
return {
  type = ..., -- a string constant used to distinguish between the different types of constructions
  description = { -- name and description for the menu
    name = ...,			
    description = ...
  },
  buildMode = ..., -- used to select the build mode
  categories = { ... }, -- used to filter elements in submenus
  order = ..., -- used to order the elements in the menu
  skipCollision = ..., -- skip collision (useful for decorative assets)
  autoRemovable = ..., -- can this construction be removed when other elements should be built at this position
  updateFn = function(params)
    local result = { }
 
    ... -- fill the result with content
 
    return result
  end
}
end

Most of these files can be found in the res/construction/ directory. See the documentation of constructions for further details.

The model resources consist of the following file types:

• .mdl for model definitions
• .msh for mesh index files
• .msh.blob for mesh 3D data
• .mtl for material definitions
• .ani for extracted animations

Model files are a special kind of configuration file as well, thus their structure is similar with a data()-function.

function data()
return {
  boundingInfo = { ... }, -- optional bounding box used e.g. for render borders
  collider = { ... },     -- optional collider for collision calculation
  lods = { ... },         -- geometric information for 3D data and textures
  metadata = { ... },     -- metadata depending on model type
  version = 1,            -- required to distinguish from the old Transport Fever 1 model format
}
end

Detailed information about bounding boxes, colliders and the lod tree can be found in the model documentation.

The mesh files contain the threedimensional mesh information known as the actual 3D model. A mesh can consist of more than one submesh. This data is stored in a binary blob file that contains all the positions, orientations etc. of every vertex, edge and face. To tell the engine where the right information is stored in the binary blob file, there is a second file with indices. This text based file can be edited with any text editor.

function data()
return {
  subMeshes = { ... },
  vertexAttr = { ... },
}
end

Both files share the same name, but the blob file has .blob as a suffix. For example, if the index file is called cube_lod_0.msh, then the blob file is called cube_lod_0.msh.blob. Read more about meshes and the internal structure of these files in the mesh documentation.

Materials contain the reference to texture files. The basic structure is a data() function as well.

function data()
return {
  order = 0, -- used to determine rendering order between materials of same type
  params = { ... }, -- parameters vary depending on type
  type = "PHYSICAL_NRML_MAP",
}
end

There are many different material types available. For a full overview of available types, see the material documentation.

If animations are extracted from .mdl files to external files, they are located in .ani files.

These files contain a data() function as most of the other resources:

function data()
return {
  times = { 0, ... }, -- timestamps in milliseconds from 0 as begin of animation 
  transfs = {
    { 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, }, -- transformation matrix for each timestamp
    ...
  },
}
end

The number of timestamps must equal the number of matrices!

There are two common file formats used for textures in Transport Fever 2, uncompressed .tga files and compressed .dds files.

.tga files usually are used for UI elements and smaller graphics. For Transport Fever 2 it is important to not use the RLE compression. .tga-files have to be uncompressed.(This restriction is not valid anymore.) As their filesize is greater than the file size of a similar image with compressed .dds-format, it is recommended to not use .tga for larger images.

The .dds file format superseded the .tga format for the model textures. In contrast to it, .dds textures for Transport Fever 2 are compressed and have a smaller filesize, reducing the memory usage.

The common compression types supported by Transport Fever 2 are:

• DXT1 with binary alpha information
• DXT3 with 4bit alpha
• DXT5 with interpolated alpha
• 3Dc for normal maps

While DXT1 has the smallest file size, it is only suitable where no transparency or full transparency (either 100% opaque or 100% transparent) is needed.

For normalmaps, the 3Dc ATI2A2XY standard is required. See external tools documentation for more information on tools supporting these compressions.

A detailed explanation on the requirements of sound files can be found in the sound effects documentation.

A detailed explanation on translation and localization modding can be found in the localizations documentation.