_skybox causes portal brushwork to disappear "fogclip-l

[thore]

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)
http://img388.imageshack.us/img388/1849/200508211129001024losttemple2d.th.jpg (http://img388.imageshack.us/my.php?image=200508211129001024losttemple2d.jpg) http://img388.imageshack.us/img388/9670/200508211129081024losttemple0i.th.jpg (http://img388.imageshack.us/my.php?image=200508211129081024losttemple0i.jpg)

This issue is present regardless of _scale value.

Thanks!


[update]

Ydnar's testmap "shaderlab_skybox" sadly features the same behaviour:
http://img387.imageshack.us/img387/3394/2005-08-21-152429-shaderlab_skybox.th.jpg (http://img387.imageshack.us/my.php?image=2005-08-21-152429-shaderlab_skybox.jpg) http://img387.imageshack.us/img387/4194/2005-08-21-152433-shaderlab_skybox.th.jpg (http://img387.imageshack.us/my.php?image=2005-08-21-152433-shaderlab_skybox.jpg) http://img387.imageshack.us/img387/1919/2005-08-21-152440-shaderlab_skybox.th.jpg (http://img387.imageshack.us/my.php?image=2005-08-21-152440-shaderlab_skybox.jpg)

http://img387.imageshack.us/img387/807/2005-08-21-152526-shaderlab_skybox.th.jpg (http://img387.imageshack.us/my.php?image=2005-08-21-152526-shaderlab_skybox.jpg) http://img387.imageshack.us/img387/6237/2005-08-21-152528-shaderlab_skybox.th.jpg (http://img387.imageshack.us/my.php?image=2005-08-21-152528-shaderlab_skybox.jpg) http://img387.imageshack.us/img387/6472/2005-08-21-152530-shaderlab_skybox.th.jpg (http://img387.imageshack.us/my.php?image=2005-08-21-152530-shaderlab_skybox.jpg)

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

[Shallow]

As I understand it, _skybox bakes a scaled up version of the drawsurfs that are generated from the skybox into the BSP and then frigs with vis somehow so that they cn be seen, essentially you are getting the skybox geometry placed into the world in the place where it would actually be, but without such a great impact on as you would get on BSP size and vis times if you built it at actual size, in place. So this isn't a bug, it's the fogclip/farplanedist functions doing exacly what you have told it to do - the geometry in the sky is further away than the clipping plane, so it gets culled.

I don't get why you would be trying to combine any skybox that doesn't have a fog mask layer (i.e. Radar style sky) or isn't blank (Railgun) with fogclip anyway, I can't think of any example of combining distance-culled world geometry with a detailed sky that isn't going to look incredibly wrong.

[thore]

Of course distance-culling would look weird without having a fog hiding the action... propably that's the reason
why I have no fog, fogclip or farplanedist parameters specified ;) There is culling, but I haven't told
the engine to do so. That's what bothers me... I just don't get it.

:moo:

[Detoeni]

ydnars skybox map works fine when you vis it properly.

[thore]

Hi Detoeni,

What does "properly" stand for?

I've tried various -vis setups even a full -vis without -fast switches etc and still have some brushes playing hide and seek.
Maybe I'm going to try some earlier q3map2 version tomorrow...

[Detoeni]

I was messing around with the map in q3 a week or so back, compiled with 2.5.16, with full vis. no problem.

I'v not had any problems using skyportal's in et, so long as I stay clear of fog.

edit:
I just tried shaderlab_skybox in et and get the same as you. ummm

[thore]

I'm not sure whether this is a good or a bad sign :D

At least I'm happy that this _skybox behaviour isn't my fault, since you get similar results.
If this really is some kind of ET-only related issue I'd like to start crying for Ydnar now...

Though I haven't tested an earlier q3map2 release yet.

[Shaderman]

I've got exactly the same problem in my own and in ydnar's sample map :/ 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.

Same problem with 2.5.11. This feature seems not to work properly in ET or are we still missing something?

[Detoeni]

The _skybox feature of q3map2 was intended to add the sky portal effect to q3 games that did not originaly comes with portal skys, like Q3. rtcw and et both have portal skys already, so I'm guessing making it work in these games was not something that was looked into.

[ydnar]

Are you using -meta?

[Detoeni]

yes, meta was used for the test I did. I'v tried a few times to get it to work in ET without sucsess. the polys in the skybox get drawn but when you look stright at them they vanish.
This is only a problem with q3map2 skyportal the one in ET works as it should unless fog involved.