"Thumbnails" container

The Thumbnails container is part of the TrainzBaseSpec, meaning that any asset may specify a thumbnail or preview image. This obviously makes more sense in some cases than in others, but certain circumstances, such as DLS, requires some imagery for every assset. The exact usage of this image may vary depending on the asset kind and the build of Trainz.

Note: The Art files directory used in old versions of Trainz should no longer be used- the Thumbnails container replaces and extends this functionality.

 TIP: For assets which have no physical appearance (engine-specs, horn sounds, etc.), you can use a stock splash screen that describes the asset type, or simply the thumbnail of the matching locomotive asset.

Any number of thumbnail entries may be present, however it is recommended that no more than 3 images are used. The specified width and height must match the actual width and height of the image file in pixels.

The DLS thumbnail is a general view of the asset, and may include identifying text or logos. This must always be 240 x 180 pixels, and must be in jpeg (jpg) format.

Asset Specific Usage

All assets must have the default 240x180 thumbnail specified. In addition to this, different assets in Trainz may use other images in the thumbnails container for different purposes. This section is still under construction, additional asset kinds will be added in future.

Traincars

Traincars require two different images to be complete. These are:

• 128x64 - ‘kind traincar’ list icon in Surveyor.
• 240x180 - Download Station thumbnail image - mandatory, and must be in JPEG format.

The list icon should show the rolling stock asset in a full side-on view, with a transparent background. The image should be centered horizontally, and with the base of the asset (the track level) at the vertical center. This arrangement means that the asset displays correctly in the Surveyor list, in the drivers list in QuickDrive, and also in the consist display that is provided at the bottom of the Surveyor screen. Since a transparent background is required, a 32-bit tga file format (referenced from a .texture.txt file) is recommended.

An example of a traincar's thumbnails container is below:

thumbnails
{
 default
 {
   image                               "thumbnail_0.jpg"
   width                               240
   height                              180
 }
 
 01
 {
   image                               "icon.texture
   width                               128
   height                              64
 }
}  

In this case, the 'icon' image for Surveyor is referencing a .texture.txt file, which in turn should reference a 32bit tga file with alpha channel.

Routes

In TRS2019, routes should have between 2 and 4 images present. These are:

• 240x180 - Download Station thumbnail image - mandatory, and must be in JPEG format.
• 1280x800 - Preview images shown in the Driver/Surveyor menu.

An example of the thumbnails container with 1 thumbnail and 3 preview images is found below:

thumbnails
{
 default
 {
   image                               "thumbnail_0.jpg"
   width                               240
   height                              180
 }
 
 01
 {
   image                               "1.jpg"
   width                               1280
   height                              800
 }
 
 02
 {
   image                               "2.jpg"
   width                               1280
   height                              800
 }
 
 03
 {
   image                               "3.jpg"
   width                               1280
   height                              800
 }
}

You should aim for the three screenshots to be 1280x800 pixels so that they fit the space available.

Other Assets

There are several other assets, such as commodities and driver commands, which may make use of the thumbnails container for icons, and similar.

For most of these, they will use the following:

• 32x32 - standard icon representation for display in lists.

Texture (Non-Environmental) assets use the following:

• 64x64 - standard icon representation for display in lists.

Supported image formats

Supported image formats include:

• 32-bit uncompressed targa (.tga) - this supports an alpha channel
• 24-bit windows bitmap (.bmp)
• JPEG (.jpg) - a 240x180 JPEG format thumbnail is required for the download station.
• Texture file (.texture.txt) - strongly recommended. This format should be used for everything other than the DLS format thumbnail.

Usage in Trainz

When displaying an image, the closest-sized image required by the function (in terms of pixel dimensions) will generally be used in Trainz. The container numbers are simply identifiers and have no meaning in themselves.