Program to create skybox?

Use the "CubeTheSphere" tool to create the 6 images needed for a skybox (from 1 original image). That's right. All the work is done for you. You can even select the resolution (up to 2048x2048) per map.

the link is below:

http://darendash.home.comcast.net/~darendash/CubeTheSphere.html

once it creates your 6 images, simply add them to your skybox material in Unity in the appropriate spots (back, front, top, bottom, left, right)

hope this helps.

Shawn

If you use Blender, take a look at this post on the Unity Forums...

http://forum.unity3d.com/threads/37264-Blender-Skybox-Generator-(!Screenshot!)

Also take a look at this link for creating skyboxes using Bryce

http://www.terathon.com/wiki/index.php?title=Making_a_Skybox_Using_Bryce

I found Terragen is quite usefull for that, just place the cam in the scene and turn it 90 for each side.

here is a short tutorial http://rabiuls.wordpress.com/2010/09/21/making-skybox-with-terragen-for-unity-3d/

and here terragen http://www.planetside.co.uk/content/view/16/28/

Since Shawn has already plugged my utility, I'll also mention UniSky (google it) and Unity itself. If you set up a nice scene in unity, there's a script on the Script Wiki that will generate those 6 textures for you

Use Terragen, it is amazing and easy to learn. The unique problem is your computer (maybe), because terragen needs a good CPU to render SkyBox with high quality.

This screenshot of my game show an old skybox I did using Terragen (only to test the render)