Have a look at CyberSpace in Dystopia to see how it can be done. You can easily get the surface normal via the ClipVelocity function in the gamemovement code. The 3d maths is a bit tricky, but the hardest part is finding and removing all the checks the hl2 engine has to stop you moving freely in...
"plausible deniability" dosen't equal "copyright permission". If your mod ever gets close to being released, expect to hear from Eidos then.
And then it's ankle grabbing time.
There was a lot less code, art and map resources needed back in the olden days, it's a lot harder to get a game into a playable (let alone releaseable) state with these next gen engines.
At the moment, VAC2 dosen't do much to help protect against cheating in mods, and as such we don't have any methods to prevent against people altering huds, etc. In light of this we tryed to design the game so changing this sort of stuff wouldn't have any significant effects on gameplay...
No, CRC checks are a stupid way of fixing it. I hardcoded the VMT into the dll in update 1, which was about a month ago.
And i'd just like to say thanks gusdor for trolling yet another dys thread!