Egir.dk

The NULL texture;



The texture is not blue for any specific reason, it could be any colour or design but with the name NULL, it would be made the exact same during compile, as a null texture.
This tutorial aims to help those new to mapping or even those a little more advanced just how to use it, where to use it and most of all, why to use it.

In this screenshot from hammer, I have built a simple brush with 1 face textured with a crate and the rest NULLed



If I compile the map, this is what comes out;



You can see I have used wireframe (gl_wireframe 2), and you can see the face of the brush where the crate texture is, has the wireframe around it, but there is no wireframe around the rest of the crate. The engine hasnt drawn it, but it is there. I know this as I am unable to walk through the place where I put the brush.

This is what the box would look like in wireframe if no nulling existed,

Why is this useful? Well if your making complex brushes, like cliffs or rocks and only the front of the brush is visable then why make the engine draw the back of the brush, why not NULL it and have the engine draw less? In doing this you will boost performance in your map;

Example, Cliffs (Advanced vertex manipulation)

Here are some well made cliffs by Naigel
I will be using these as a good example of why to NULL.


As you can see here, the back of the cliffs are using the NULL texture, as they wont be visable to the player.
On compile and running of the map in Developer mode, Wireframe enabled (gl_wireframe 2) you can see the FPS and polygons that the player is able to see, in this case:


125 FPS 185 wpoly and 0 epoly as there are no models being loaded by the engine (Notice no hands or weapons)

Now I will recompile the map without the use of the NULL texture anywhere,



As you can see the Polygon count and FPS have changed significantly,
94 FPS 210wpoly and still 0epoly for the same reason above.

Thats a difference of 31 FPS and 25wpoly, just from something as simple as texturing differently, in just this small test map.

In mapping this is a great way to pick up on performance here and there making the overall outcome better.
Say you were making a large map and had much more of this advanced brushwork it would be vital to pick up on any performance gains anywhere possible, like NULLing.


Floyd's note: NULLing is also a useful way to make transitions. Extend the transition further past the point where the level changes and use NULL on any surface that wouldn't be reachable by the player. Seamless changes work much better this way as the NULL surfaces will act like normal walls when it comes to lighting, which prevents those ugly lighting changes that we all remember from the original Half-Life

Credit:
Soul
Naigel, for his cliffs!
The egir.dk community

Thank you.

supperb.

You were unable to walk through the null textured brush because when filling the map (figureing out where the actually hull goes) the calculations are brushbased, and the null-brush is still just a worldbrush, so there will be done filling around it, that is, you can't walk through it.

Also note that there has been done clipping around it, indicating that it blocks vis, which is why there is an open view to the void right through the floor.

Interesting and well written. I hope more people will get to know the use of the NULL texture.

wow that will help alot thanks

I have a question... Can I use the sky texture aswell as the null texture?

the null texture is better.

I see... In what ways is it better?

But you still need the sky texture around the map, right?
Cus would have been weird, if you just have the null all
over the place...

If you are talking about making it as a hollow box, then NO Its bad would give you high R_speed /which the tutorial is trying to kill)...

Btw put you pic in signature so you don't have to put it in by yourself

Of course you'll need SKY in order to have a sky in your map, but it's something different than using NULL texture.

Help please! I don't have a null texture in my halflife.wad!

isn't it in the zhlt.wad ? (which comes with the ZHLT compiling setup.)

it is.

i dont get it when i compile my map with zhlt it comes out the same as in hammer

So when u make a hollow sky box around ur map ,ur wpoly woulb b verry high ?

yeah, you should instead make the sky as a 'ceiling' just over each outdoor room.