I want to create a 2D skybox corresponding to a starry night. The problem is this: I can't find the appropriate skybox texture name for that. I've entered sky_white, sky_black and sky_fog, and ALL of them give the same dark-bluish kind of a "sky", which doesn't seem like a night sky by any stretch.

Would appreciate help of any kind..

Four seconds;
Valve Developer Community. Search function. Portal 2 skybox list.

look here

EDIT: okay, my bad. Looks like Portal 2 doesn't have one as a default skybox texture. You might have to create it.

15 seconds;
Game Banana. Search function. Space skybox.

Begin Looking for one you like.

Yes of course I've already looked at it. And as I said, no matter which skybox texture name I try, the result is always a dark bluish kind of texture above...

EDIT: I see... but as far as I remember there was a night-sky skybox in one of portal 2 chapters? (the wheatley finale for instance)

Yes, there was.... hmm... Hammer, Texture Browser, Skybox in the filter. Try out "finale_stars" for your skybox ?

Or try this one I got from GameBanana (I think) over a year ago... see attached

Xtreger wrote:
but as far as I remember there was a night-sky skybox in one of portal 2 chapters? (the wheatley finale for instance)

Those are 3D skyboxes. I don't believe those textures work for 2d. https://www.youtube.com/watch?v=40oIyq5IWPk

Doesn't work There are several textures like skybox/br_stars01, skybox/stars01, so I tried entering "stars01", "finale_stars" and "br_stars01". In all these cases I get a distorted visual glitch when I look up, which seems to indicate that these aren't recognized as valid skybox texture names. The only ones that work are those listed on VDC

@RustyDios: Thanks! In what directory do I put the files from the archive?

@iWork925: That makes sense. It's why they're not valid "textures" I suppose...

They go into materials/skybox folder... you might need to create it. Then use stars01 as your skybox name... that should work..

EDIT : even though its for TF2, this tutorial is actually really good I think at explaining skyboxes... the same principles still apply to Portal2

Xtreger wrote:
Doesn't work There are several textures like skybox/br_stars01, skybox/stars01, so I tried entering "stars01", "finale_stars" and "br_stars01". In all these cases I get a distorted visual glitch when I look up, which seems to indicate that these aren't recognized as valid skybox texture names. The only ones that work are those listed on VDC

The problem with the skyboxes from gamebanana etc are that they're for not-portal-2-games, and afaik the vmt's have the "Sky" shade, which, in portal 2, causes the weird glitch.
If you change the first line of all vmfs from the sky to "LightmappedGeneric" they should work

Yeah true. I had already changed the .vmt for the Space/stars to UnlitGeneric. Maybe LightmappedGeneric would be better... ...

I changed the UnlitGeneric's to LightmappedGeneric as lpfreaky said, still getting the same visual glitch. I'll try to find an alternate way to simulate night environment.

Thanks for the suggestions so far!

"UnlitGeneric" is what the standard Portal 2 skyboxes use. I don't think "LightmappedGeneric" makes much sense, since the 2D skybox doesn't have a lightmap applied.

Remember to also remove the "ignorez" line if there is one, otherwise the skybox will fill the whole screen whenever it's visible, hiding the rest of the map.

Space Skybox worked for me in a simple test map (the way I sent it to you);

Pic1
Pic2
Pic3

Just noticed you might want to copy say stars01dn.vmt and rename/replace stars01bk.vmt ...
The bk texture file is the one with the planet earth image.. the rest are all just generic starry skies...

PS The test box room was a simple square box, 2 walls & floor textured with anim_background and 2walls and ceiling textured with tools_skybox. Map properties skybox name set to stars01. All textures (vmt & vmf) in materials/skybox...

No luck so far... my purpose is just to convey as good an impression of night-time as possible.

Earlier I had made some holes in the ceiling and inserted the tools/skybox into them. When that didn't work, I inserted brushes into the holes and textured them pitch black. But I also put an env_fog_controller, checked its Master flag, set Enable Fog to Yes, min distance 1, max distance 8, fog density 1, but I STILL don't see any fog!

This time I've attached the vmf of the map (which is structurally very simple)... I don't get why the stars skybox is showing the visual glitch, despite following RustyDios' instructions.

In your .vmf I found 2 major mistakes related to skybox:
1. You should apply texture tools/toolsskybox to all faces you want your sky to be seen.
2. In map properties you should set SkyBox Texture Name parameter to your skybox name (stars01 if you use RustyDios' texture). You have sky_black_nofog (btw that nofog part doesn't let you have fog in your sky).

In env_fog_controller set propper values for fog start and fog end (let's say 1 and 2500, not yours 0.000025 and 0.0025 or so ) and choose a good color (somewhat bluish or darker). And experiment with these parameters.

A 3d skybox might be a better fit here. Like the one in the super8 demo.