GPL Track Creating - trk23dow - TEX
Authored by the GPLEA
<trackname>.TEX - Texture Mapping
In order for trk23dow to map the right textures to the right polygons, you must create a <trackname>.TEX file that relates to the values specified in your TRK.
Surface Subtypes
By now you should understand the different TRK surface types, but this will only let you define 1 texture per surface type- hardly a graphically pleasing track. To overcome this, the Unknown3 value in the TRK Walls is used as a surface SubType value, letting you have e.g. Asphalt 0, Asphalt 1, Grass 42, Armco 4948583, or whatever (maximum value of 2^32-1).
That .TEX File Then...
Here are the first few lines from a .TEX file:
0 0 0 10.0 10.0 error
1 0 0 10.0 10.0 asphalt
1 1 0 10.0 10.0 road
1 2 0 10.0 10.0 run
1 3 0 10.0 10.0 asf_shw
1 4 0 10.0 10.0 asp_sl
1 5 0 10.0 10.0 asp_sr
2 0 0 15.0 15.0 dirt
2 0 1 20.0 20.0 dirt
2 0 2 20.0 20.0 dirt
2 0 4 20.0 20.0 dirt
2 0 5 20.0 20.0 dirt
The first number in each line is the surface type - 1=asphalt, etc.
The second number in each line is the surface subtype - the value corresponding to the Unknown3 value in the TRK.
The third number is the 'side':
0 = normal texture, mapped on to the top of the wall
1 = vertical surface - e.g. side of armco
2 = upper ground-level polygon - e.g. top of armco
3 = ground-level, reflected - for when the track is visible from underneath.
4 = front of the wall (longitudinally)
5 = back of the wall (longitudinally)
6 = ceiling - e.g. the inner-top of a tunnel
The fourth number is the longitudinal scaling value - e.g. the asphalt texture will be mapped every 10.0 metres.
The fifth number is the lateral scaling value - (left-right).
The last part is the MIP name to use.
Note the first line - this is 0 0 0 10.0 10.0 error. Here you should define a texture to be used in case you forget to define a texture for any surface.subtype combinations. Make it a texture that you can easily spot in GPL, so you can work out where the problem lies.
See how surface type 2, subtype 0 has five textures mapped to it. This is because somewhere in the TRK, surface 2, subtype 0 has been given height, to make it into a vertical wall.
If you use any of the Unknown4 flags to change the texture mapping, the scale values defined in the .TEX file are overridden.
Updated 7-Jan-2001
Transferred to the wiki: 19.04.2009
