Vu2U is a small utility for 3D game programmers and SketchUp™ modellers that does just one thing for the moment : it converts «cube» skyboxes exported by apps like Vue Infinite™ to a format that is readable by the Unity™ game authoring system, or by Adam Billyard’s excellent lightmapping plugin for Google SketchUp : LightUp™ .

To use it :

1. 1)Export a skybox from your preferred sky creation app in the “cube” format, with a 3 x 4 size ratio and both sides being powers of 2 (ex. : 768 x 1024)
   

2. 2)Launch Vu2U and drag your skybox picture to its small floating window, or simply drag it to Vu2U’s application icon.
   

3. 3)Click on “Save for Unity” or “Save for LightUp”, choose the asset folder of your Unity project (or the folder of your choice for LightUp) and assign a name to the extracted files. Note  : if files with the same name already exist in the directory, they will be erased.
   

4. 4)Unity will automatically import the 6 resulting pictures, which will be named in a convenient way to help you drag them in the right order to the 6 slots of a Unity skybox material : “Skybox 1 Front (+Z).jpg”, “Skybox 2 Back (-Z).jpg”, etc. If the skybox is active, it will update you game scene.
   

That’s it ! In Unity, remember to select “clamp” in the properties of each imported picture - otherwise your skybox will look like a box ! You just have to do this once, since Unity will remember these settings as long as you export with the same file names.

In LightUp : go to the preferences, check «Show skybox» and select one of the generated pictures by clicking on the yellow box on the right. If you also want the skybox to contribute to your scene’s illumination, you’ll have to select «Ambient Occlusion» and then «IBL blend». This can be of course combined with Direct source lighting.

Also, you will notice two checkboxes in Vu2U : “Auto reduce window” and “Auto transparency”. They’re here to modify the window’s behaviour.