I searched "terrain" and nothing came up about what I was looking for so here we go..

Ok. When Im making terrain ( clip and vertex tools ) it looks nice in Hammer but when I compile it, its like I didnt move some of the pieces. I dont really know how to explain it.. Its like the compile decided on making its own terrain or something.. Here is a pic with a Hammer screen and an ingame screen. This happens whenever I try and make terrain and its really getting me angry.

http://www.dodstudios.net/uploads/uploads/fibstest.jpg

:(

Your most likely making all the brushes that move invalid. Press Alt+P with your map open in hammer and it will tell you if you do.

Yeah I forgot to add that I alt+p'd it and when I clicked to fix them it just.. screwed it up. What do you mean by "making all the brushes that move invalid"? Sorry for all the noob questions... :(

no problem. But you might want to try and make your brushes triangles, then tie them together. Ill get a pic from a map im making and give you an example.

EDIT: ok, heres a little sample thingy i made http://www.dodstudios.net/uploads/uploads/map10001.jpg i highlighted the triangles so you could see what i did and stuff. After you get familiar with doing it, it gets to look pretty good. Only problem is that if you have too much it can lead to high r_speeds. This is the best way to make good looking terrain that I'm familiar with.

the problem is that when you manipulate vertexes or squares, sometimes it makes them curved, or angled, or other wierd stuff that dosent work with hl. hl is fixing the problem brushes automatically ingame. break up your brushes into triangles, and the manipulate.

Yup, triangles ONLY for terrain manipulation.
Rectangles that have had vertices manipulated may no longer be FLAT, so the compiler will take a best guess.
Actually to fix your problem, cut your bad piece in half (into 2 triangles) and you will see where you screwed up.

Thanks for the help everyone! I got it fixed now... Thanks alot :D