I just used billboards, if you look at the files you see the billboard textures and their .mat files. Study them and you're set, its nothing complicated.
But if you really want to make a glowing texture, then you'd have to give the .mat illumination.
quote from
here:
"
Illumination map
Size: Half of diffuse
File format: dds, dxt1.
Suffix: “illum”.
This map will be added additively on top of the model when rendering and
will not be affected by lighting. It is useful for creating glowing
surfaces such as lightbulb, ember, etc.
With size means the size of texture width and height. So if diffuse is
512×512 in size, then a map with half of the size of diffuse will be
256×256. Normal simply means that it has the same size of the diffuse
texture. Also note that the size of map might be specified otherwise in
the description of an object, and if so the specified size shall be
used."