cube map for skybox (UT2004), Help needed plz.

armagon9177

hello,

i've been working on a 100% custom, meshes, textures etc. map for Unreal Tournament 2004. things are going extremely well on it. when i decided to tackle my skybox i took a look at some of the other maps in particular CTF- Face 3 as it has the general effect i am going for.

i'm not 100 percent on how this was achieved but the material for the subtracted BSP for the skybox is curved perfectly as to allow a perfect perspective from the location of the SkyZoneInfo actor. the material/texture bends correctly and i am seeing a set of 6 DXT5 materials in the texture browser there. does anyone know how this was achieved? how the source art was distorted perfectly for that specific perspective? the horizon and the planet curve looking at the material in the texture browser.

i would really like to know the workflow to this. i have max and photoshop. any help would be GREATLY appreciated.

thankyou.

edit* equirectangular projection is what it's called. apparently cameras need to be set up for each texture in max and the perspective you want. though the process is still unclear to me, so i would still appreciate anyone who has experience with this weighing in.

Ben Apuna

This might help you with setting it up:

http://udn.epicgames.com/Two/ExampleMapsSkyZones.html

EDIT:

Here's one more

http://udn.epicgames.com/Two/MaterialsEnvironmentMaps.html

armagon9177

thankyou Ben, i know the implementation though.

what i'm trying to figure out is taking my source art, what i've created in photoshop and getting each of the 6 sides to bend and distort like a 360 degree X 360 degree panorama which is extremely convincing and looks like you're using a perfect sphere.

it's a certain technique that photographers use for panoramas but also used by EPIC to fantastic effect in CTF- Face 3. my research has brought up that this can be done in Max somehow.

it's very similar to this:
http://hugin.sourceforge.net/docs/manual/Big_ben_equirectangular.jpg
but sliced into 6 images retaining the distortion it looks like a perfect seamless sphere of the world. because of my desire for a massive planet or moon and that being too large for a static mesh this is my only option, well for it to be perfect. and i have future projects in mind that would benefit as well. long posts just trying to describe this effect.

thankyou again for the links. i will need to revisit those.

EDIT: better yet this is what i'm going for. the distortion is seen in the sky. http://www.modwiki.net/wiki/Image:Cubemap_example.png
its driving me crazy.

Ben Apuna

What I remember doing in the past was mapping a rectangular sky texture to a half sphere placing that in the level and then using the above techniques to apply it as a skybox fake backdrop to the outer BSP shell of the level.

EDIT: I think it may have been a full sphere rather than a half sphere for the skybox mesh.

If you were using the Unreal Tournament 3 editor I would suggest creating a giant half sphere static mesh and using that as your planet or moon.

I think I've seen a plane with a alpha cutout moon placed in a UT2 level somewhere, but it's been so long I don't remember what level it was in. That might work if your planet or moon isn't too massive.

divi

map the undistorted sky you painted to the sides of a giant cube, turbosmooth it until it's round and do what ben cloward describes under "Creating a Cube Map from A 3D Environment" http://www.lumonix.biz/yabb/YaBB.pl?num=1170849816/5#3 with the smoothed cube being the environment.
i'm not 100% sure if this will result in exactly what you are looking for but who knows. might be worth giving it a try .

cman2k

yeah dude you can do this out of 3dsmax pretty simply. the Ben Cloward thing will work but there is another more automatic explanation here if you need it;
http://wiki.polycount.net/Cube_Map

internets

armagon9177

thankyou very much,

i'm off to try this. i'm always amazed at the help i receive here. i'll let you guys know how it goes.

EDIT: blah, just not having any luck with this. difficult for me to grasp sourceart > max > cube map workflow. any very simplistic step by step tutorials on this because there seems to be many threads on the internets but nothing crystal clear such as step 1... pop up book pictures help me too.

i'll eventually get it after much more pain. just feel out of my element here.

Eric Chadwick

Hey, got your PM, thought I'd answer here. Maybe this tutorial might help?
http://www.ericchadwick.com/examples/tutorials/multi-photo_panoramas_in_max.html
I'v since discovered easier ways of generating panos from photos, but this might help you with your painted art, if you have Max. Though you could probably transfer the ideas to any 3D software.