This tutorial will show you how to have COD4 godrays and custom effect shaders! These techniques are displayed in my new map mp_Nightshift! 
-AFIRSTTIMEMAPMAKER

This tutorial is a mostly advanced tutorial but a beginner can do it if they really wanted too.

Lets first start off by downloading the COD4 godray texture in TGA format.

http://www.mediafire.com/download.php?e9anvaaj4ah1gek

Extract the image to your IMAGES folder in the MAIN directory of COD2/4/W@W/BO (this technique can be applied to any new COD that has mod tools)

Now open ASSIST MANAGER:

1. Go to the white box, scroll down to "MATERIAL"
2.Press "New Entry"
3. Type in "cod4_godray"

4.Press "OK"

Now do these next steps carefully.

5. set materialType to UNLIT (i did a mistake in the picture, thus is why UNLIT looks weird...lol)

6. Change surface type to "NONE", do NOT keep it at "", cause if you dont, when you compile the image you will get *drumroll please*....an error, surprising right? 

Keep "sort" the way it is, now change "usuage" to SKY.

7.Put the "locale" as "Kiev"
 
8. Change "blendfuc" to "ADD"

9.Change "CULLFACE" to "NONE", this prevents the texture from "disappearing"  when you go "behind" it, the texture will now appear at all angles now instead of only from the "Front"

10. Enable Z-FEATHERING.

 11. Find the image, I had my image in a custom named folder, you should have yours in the IMAGES folder.

READ CAREFULLY BELOW!!!

12. Go to advanced options at the bottom, change platform to PC/XENON, DONT FORGET THE NEXT STEP!

 13. Go to ALPHA and change it to "ENABLE", now to go FILE, and save, make a gdt file.

Now after thats done, convert the image, and you are done! Now  go to Radiant > TEXTURES (At the top of the toolbar