Hi there!
Props_skyportal seems to be a little buggy creating unwanted HOMs so i followed the
advice of a fellow mapper to use _skybox instead. HOM’s gone, hurray, but what’s that?
Suddenly some brush faces of the portal brushwork disappear when exceeding a certain
distance between brush face and player.
This somehow reminds me of the behavior of the worldspawn keys “fogclip” and “farplanedist”
although I have none of those keys specified. Setting fogclip to 10000 for testing purposes
didn’t help so I’m quite curious what causes this behaviour. Since I don’t really know what
to search for I havn’t found anything usefull… hints appreciated.
First image shows some invisible faces. Going one step backwards causes even more faces
to disappear (second pic)

This issue is present regardless of _scale value.
Thanks!
[update]
Ydnar’s testmap “shaderlab_skybox” sadly features the same behaviour:

Compiler is q3map2 2.5.16 via q3map2build GUI “bsp: normal, vis: none, light: normal”



There 
I’ll try a compile with 2.5.11 when I’m at home - AFAIK this feature was announced in this version and should work. Maybe something changed in the following releases.