skyportal trick?

[silverwest]

In Unreal Tournament, there's a level that takes place on a boat. The water is clearly touching the boat, but goes all the way to the horizon seamlessly.

 

Does anyone know how this was done? Can it be done with some trick involving a skyportal (which are now available in JA)?

 

[To those who don't know, a skyportal is an alternative to the standard skybox. You make a room that serves as a skybox, put in a misc_skyportal in that room, and use caulk for your skies. It allows you to have moving objects in your sky among other things.]

[Emon]

I didn't think that was done with a portal sky in UT. I always assumed they just made a bigass box with a big plane of water, and aligned it with the sky textures, which could have been manually placed, instead of doing it like you would in Q3 (with a shader).

[Greymon]

To those who don't know, a skyportal is an alternative to the standard skybox. You make a room that serves as a skybox, put in a misc_skyportal in that room, and use caulk for your skies. It allows you to have moving objects in your sky among other things. [/b]

 

silverwest, can you actually put moving objects in your portal sky? Have you tried it? I tried that today, using rail_movers. The portalsky stationary objects showed as normal but the movers did not.

[silverwest]

thanks, Emon. that seems more straightforward.

 

Greymon, i'm not sure what works and what doesn't. i haven't experimented with moving objects yet. I think in UT that's how they did the orbitting asteroid in facing worlds. I looked at a website about portal skies in a Q3 mod called Weapons Factory, and it seems you can't have entities in the portal sky in their version of it. I guess the point of it there is to allow mappers to make somewhat custom skies without an additional 3D program.

 

However, I was speculating that in JA they used a portal sky for the SP mission on the tram, with a script rearranging the buildings to keep repeating.

[Greymon]

Originally posted by silverwest

However, I was speculating that in JA they used a portal sky for the SP mission on the tram, with a script rearranging the buildings to keep repeating.

 

Thats exactly what I was experimenting with. Thats not how they did it. I dont even know for sure if there is a portalsky on that map. The moving buildings are rail_movers. That much I know. They're not in a portalsky, they're actually right next to the tram. What you said was my first guess as well, but when I set rail_movers in my portal sky, they didn't show.

[silverwest]

i kinda wonder what the advantage of it was in JA. I'm pretty sure they used it in the Hoth Siege level. In there, the skybox mountains seem to be 3D while the rest of the skybox looks pre-rendered. Maybe the advantage here is to avoid the contrast in looks between pre-rendered and the close-up in-game mountains.

 

I think skyportals were also used for levels with moving clouds, such as the first Yavin SP level. Moving clouds can be done with regular skyboxes, but there is a curve to them, and they look ridiculous if the player can ever see the bottom of the skybox.

[Greymon]

I haven't played with cloudlayers yet, but I know they dont require portal skies. The cloudlayers entity has an option to make them spirals if that's what you're referring to.

 

As for the advantage: Portal skies are used to enhance your map without drastically raising the r_speeds. The Tattoine spaceport map uses them (the skyscrapers), blenjeel merchant crash uses them (mountains), etc... You can reduce r_speeds by making small buildings and mountains and projecting them in 2d with portals. I guess it also reduces the bsp size.

 

I'm mostly using them to hide the 'down' texture of the skyboxes. You'll notice many of the 'downs' are simple single-tone textures that dont match the rest of the skybox. That's annoying.

[wedge2211]

Originally posted by silverwest

In Unreal Tournament, there's a level that takes place on a boat. The water is clearly touching the boat, but goes all the way to the horizon seamlessly.

 

Does anyone know how this was done? Can it be done with some trick involving a skyportal (which are now available in JA)?

 

A really cool looking instance of this sort of thing can be found in the free Q3-engine game Wolfenstein: Enemy Territory, on the Seawall Battery map. I'm trying to figure out how to do this for the JA remake of City of the Ancients...