This is the original code fixed up, with some additions (such as the fact that it uses the context menu instead of the obsolete vgui system). It makes use of leftover engine variables that weren't removed in the GM13 update (so in short the lua code is what holds it all together) as well as leftover vtfs and vmts.

Also, sorry for taking a long time to reply, I've been busy for a long time and I ran into some technical issues as well (harddrive died and everything in it was lost pretty much). I'll be fixing some quirks (as well as finding errors I didn't know were there thanks to you!) and making some adjustments to the addon once I get back. Once again, sorry for not replying!

Haha, it's fine. I used the code in here as reference for how the g_refract shader works, which I put on the wiki[wiki.garrysmod.com] and used for my own project which.... I ended up not even getting really started with.