Texture lighting is, as the name implies, lighting your map using textures. Sounds a bit odd, doesn't it? Well, it's actually very simple, but, for some odd reason, VALVe decided to stop helping you do it.
All you need is one little text file, which you should open in Notepad. When you compile your map, the compile tools will look for this file, which, for whatever reason, VALVe don't give it to you any more (since an old version of WorldCraft). However, there are many copies of this file available on the internet. The file is called LIGHTS.RAD, and you can easily edit it to make your own texture lights. You could, for instance, decide that you wanted all the STEEL textures in your map to emit light. I'll use this as an example for this tutorial.
Here's a line from LIGHTS.RAD:
+0~FIFTS_LGHT01 160 170 220 4000
Now, as you can probably see, the first bit of text is a texture name. It's that simple - you want STEEL to emit exactly the same light as +0~FIFTS_LGHT01? Just copy the line and change the texture name, like so:
STEEL 160 170 220 4000
It's that easy. All you need to divide the texture name from the numbers with is two tabs (hit the TAB key twice, just above CAPS LOCK). I'll now explain what those numbers mean.
These numbers affect the colour of the lighting: 160 170 220
. The first number is red (0-255), then green (0-255) and blue (also 0-255). So, if you wanted to make STEEL emit white light, you'd put this:
STEEL 255 255 255 4000
Bright pinky-purple would be this:
STEEL 255 0 255 4000
The last number is the brightness of the light. In the example, I have made a very bright light, but if you wanted to create subtle lighting effects, you'd probably want dimmer lights at some point. Try using different numbers. [It depends on the surface area of the texture - a very high number on a small texture won't be as bright as that same number on a huge texture. You'll just have to experiment.]
I hope I have shown you how to use Texture Lighting. If you have further questions, please post then on the forum or e-mail me.
NOTES: Download the example map for my copy of LIGHTS.RAD. You need to put this file in the same directory as ZHLT [or wherever your compilers are - the tools look for this file when you compile maps.]