Textures in Vehicle Simulator scenery are arranged in layers similar to colors
in a topographic map, for each layer there is a set of rules which determine
when it is used, these rules are:
- min_alt - minimum elevation in meters
- max_alt - maximum elevation in meters
- min_slope - minimum ground slope
- max_slope - maximum ground slope
- probability - probability for use
Each elevation point in the scenery is checked by these rules, when the rules
are met the point is assigned a texture index.
The layers are checked from the lowest index to highest, the first set of
rules that checks ok determines the index of texture to be used, further layers
For example, if we have the first layer between 0 meters and 1000 meters,
with slope between 0 and 0.5 radians, and the second layer between 0 meters and
1000 meters with slope between 0 and 5 radians, the second layer will be active
for land with high slopes, thus giving the impression of cliffs similar to the image
on the left.
The last rule to be checked is probability, this gives a probability for
using this layer even if all other rules for it are met, this enables
irregular appearance of ground textures even if the ground is flat.
This set of rules is defined inside the file scenery.txt, this
file is found in the graphics directory of the program and also inside the
directory of the scenery itself, when not found inside the scenery directory the one in the graphics is used.
This file also contains vegetation information for each texture layer.
It is recommended to use the program itself to edit and save this file,
rather than to edit it yourself, to change textures interactively from the
program see the scenery basics.
Notes about scenery textures
Vehicle simulator supports up to 16 layers of texture, with maximum size of
1024x1024, actual size of texture depends on the capability of your video card.
Scenery textures are in jpg format, and can be placed in the graphics
directory of the program or inside the scenery directory itself.
The rules you make for textures should not cause lower texture index to be
used after higher texture index is used, this results in ugly transition lines
between lower and higher texture indexes, instead design your rules to have
lower index first and higher index next.
When the scenery is loaded for the first time the set of rules is checked and
a texture index is assigned for each elevation point, the result of this
calculation is stored inside a simple bitmap called txt.bmp inside the
This file has the same width and height as the elevation matrix, and contains
pixel values which match the index of the assigned texture for each point of
To make areas of special interest in the scenery you can edit this file using
an image editor and set your own pixel values to areas of your choice, this file
must be kept in the same format as 256 colors bitmap.
The image below shows a typical section of this file.
Textures used in Vehicle Simulator scenery are best seen when high above
ground, when closer to the ground another set of textures is gradually phased
into view, these are called the dense textures, their role is the make the
ground appear denser when viewed from a close distance and also to supply ground
The dense textures are also jpg files, they have the same name as the
selected textures with the prefix of the word "dense_", if no
such texture exists the texture called dense.jpg is used instead.
These textures are also placed inside the graphics directory of the program
and inside the scenery directory itself.
By default the program creates the texture map file called
txt.bmp after each time you make changes to the textures, or the texture ruls,
however on some cases this file may not be deleted, especially if you edit the
scenery.txt file manually, in that case you need to delete the file txt.bmp and
let the program generate it when it loads the scenery.