Equivalent of null in HL2?

Whats the equivelant of the null texture in HL2 if there is one, I can't see one in the new hammer, so am I right in saying theres something different in the source enginge which eliminates the need for the null texure?

Help appreciated.

Are you talking about a texture that doesn't render?

Cause that texture is called "No Render"

Does it perform better when I apply the "no render" texture to all of my non-visible brush sides ?

tools/toolsnodraw (just search for "nodraw")

After looking at where it's used in the CS:S maps, it looks quite important/handy...

Forceflow said:
Does it perform better when I apply the "no render" texture to all of my non-visible brush sides ?

Nodraw should be used like Caulk in Quake 3/Doom 3 editing (though the better comparison is, well, nodraw :razz: But ignore that for now). Some people get in the habit of building their entire layout in caulk or null in both editors, but that's not necessarily useful - all world geometry faces that are invisible in the world are culled during compiling, so it's not really necessary to do that.

Models and detail entities don't figure into vis calculations, nor do they seal the world. This means that any polys behind them will still be rendered - giving what's called 'overdraw.' This is more expensive and more of a problem in newer engines as each polygon and material takes more and more passes by default. What you do, then, is place nodraw brushes behind these details, eliminating as much overdraw as possible. It'll also greatly simplify vis calculations in many cases, as it simplifies the surrounding geometry. I don't know the exact areaportal implementation in HL2, but it can also give you some cool options that way... but I'll leave you to figure those out for yourself. :wink:

Some entities (func_breakable_surf, if I recall?) require you to texture all but one face with nodraw, and the remaining face is rendered from both sides.

From the looks of things, there are also still some cases where using 1 unit thick func_illusionaries is necessary.

So it's only useful behind models and detail entities, and not let's say on the bottom side of a cube you're walking on.

Right. However, if the face is visible in the world from any point, but say you'll never see it, you can save some lightmap data by removing the face (even if the face normal is away from you and thus not rendered). Or, if you still decide to make a brush 1 unit off the ground for some reason, the bottom of that would be a good spot. :smile:

Thanks peeps, I really need to keep within my 'budget' on this map I think, some areas could get quite big.

ty for the explanation, KFS. I got it.