Acid/Water
How do you make the (acid? water?) that portal has? I can't find any tutorials on it...
im pretty sure theres one there. i think i read one once b4
and if not its very simple to find one as its called hazard 
just use a texture and a trigger_hurt
Create a brush with nodraw on all six sides.
Put Water_hazard texture on the top of the brush.
Create a brush the exact same size, but with tools_trigger on all 6 sides.
Entity the trigger to trigger_hurt with damage of 100, and type to chemical.
It works perfectly! Thanks a ton! *gives cake*
Put Water_hazard texture on the top of the brush.
Create a brush the exact same size, but with tools_trigger on all 6 sides.
Entity the trigger to trigger_hurt with damage of 100, and type to chemical.
can someone explain this a little better? I get the trigger, but I guess I don't have enough skill to understand the nodraw/water_hazard deal.
Nodraw is a tool texture that not rendered in the game. This is used for the sides and base of your liquid, since these will be facing towards whatever hole you have made for your liquid, and would not be seen anyway.
Water_hazard is the liquid texture that is used for the toxic goo in Portal. This should be applied to the top (visible) face that will be the surface of your liquid. By applying this, or any liquid texture, to a brush, you are telling the compiler that this brush is a volume of liquid or water, rather than a solid brush.
Note that liquids won't seal the level, and should be enclosed at the sides and base by solid world brushes.
To add something to sbrown's reply, you should also place an env_cubemap over your liquid for proper reflections, and an info_particle_system for the green mist effect. It's not strictly necessary, but it really adds to the effect, and makes things look more professional.
Thanks for the reply.
I understand all of that, but I don't know how to texture the top of the nodraw brush in the water_hazard texture. How do you have a separate texture on only one side of the brush?
This would also help in other areas of my map.
One of the buttons on the side of Hammer is called the "Texture application tool". Clicking it will bring up the face edit dialog, which you can use to texture individual faces, by selecting them in the 3D view.
I didn't even know it was possible to do that. This definitely changes things.
Well, my water hazard works now. Thank you very much!
My first test room is basically finished now. I just need to set up the end transition or whatever.
Thanks!