What's a skybox?
In Second Life, a skybox is exactly what it sounds like: a building in the sky.
Skyboxes are as varied in appearance as ground structures: they range from simple work platforms which aren't technically boxes (for building, photography, and other focused activities) to elaborate houses (like castles in the clouds!) and even whole malls. Also, places that feel natural "in the air", like space stations, could be considered skyboxes within Second Life's culture.
How can I get a skybox?
You can, as with just about everything else in Second Life, build your own. Here's a video tutorial showing how to place objects in the sky:
|Important: As shown in the video, "rez a cube and sit on it" may not work if the region you're in uses a "terrain extender", due to this bug.|
If you'd prefer the convenience of a "prefab" skybox, there's a special "Sky Boxes" category on the Marketplace and you can also search for skyboxes, as many aren't in that category (yet). The same means shown above can be used to get up there and place the skybox.
How high can a skybox be?
As shown in the limits list, the build height is 4,096m. However, the base of even a very high skybox will likely be placed below that (for example, 4,000m), allowing for room to be built upwards in case the owner wants to add an extra floor or other expansions.
Since avatars can fly in Second Life and placing objects in the air isn't affected by gravity (unless you choose to enable physics on them), making use of vertical space is very popular for several reasons, including:
- Privacy - It's less likely for both text and voice chat to be heard when it's hard to get to where you are. (Although IMs, instant messages, can be a better option since they can't be snooped on by proximity.) New Residents and casual passerby are less likely to look thousands of meters upwards. Part of this is because there's a built-in fly height limit (also shown on the limits list), which can be bypassed with a scripted "flight assist" gadget, but is otherwise a default restriction. A skybox doesn't guarantee privacy, however, and at most is a casual deterrent. Use the tools in World menu > Place Profile to restrict parcel and region access.
- Performance - What's in the sky is a lot less dense than what's on the ground. When less things need to be rendered, performance improves. Also, lack of visual clutter can help someone focus on a creative task, not unlike how distraction-free text editors have become popular.
- Immersion - Some Residents have figured out clever ways to create the illusion of a self-contained environment by putting a build inside a textured, giant sphere. This obviously doesn't work on the ground, where the terrain and water are visible. A variation on this are skyboxes that have textures on the windows that simulate city landscapes and other "fake" environments to better control the experience.
What else should I know?
There are special considerations to building in the sky:
- You should only build on land you own or otherwise are allowed to (feel free to practice in a sandbox). Don't leave "sky litter" on someone else's property.
- Check if sky boxes are allowed by the local covenant, or if there are certain restrictions. For example, the Linden Home Covenant does not allow sky boxes. Private estates may or may not allow them, or have minimum and or maximum heights for sky boxes.
- Don't let your skybox overlap onto adjacent parcels. It's hard to tell where one parcel ends and another begins since property lines are only visible on ground terrain, so watch the navigation bar at the top of the Viewer window — as you walk or fly around, if the parcel name changes to another, you'll know you're past the borders.
- You may also wish to right-click the navigation bar and check Show Coordinates so you can see exactly where you are, including height.
"Skybox" in other 3D environments commonly means a simple construct to simulate skies.