Underground Builds

Is it possible to actually build within terraformed land in anyway.

Friend wanted to make a small more private room under her main house on top of a plateau in a sim and was trying to figure out how to actually get a build inside of the terraformed land already figured out on the build what I would want seen from the outside. Which is essentially the door and a small part of what looks like a stone arch rest would be ideally fully covered by terraform of the land around it since it doesn't seem you can push prims into the land fully. I will admit that I didn't try phantom to place it and making it normal once in place.

Tried searching for anything to do with underground builds but came up with nothing though I do know of never been to various caves in SL but I am afraid they have the landscaping as part fo the build which is not what I am looking for.

What you're seeing is how it really is, you can't push an object's root prim more than a little bit under the ground. Avatars also aren't really allowed to go down there in a normal sort of way, the best you can do is fake it with sit target and animation tricks.

You could use those tricks and a root prim linked over the ceiling to make some kind of fake super secret bunker, but you'll have to go with fake prim ground if you want something that can be walked around in the normal way.

You can make the middle part of the plateau lower so it's like the cellar of the house, then cap it with the house itself and use a teleporter or secret entrance.

Terrain in SL is like a sheet of rubber. You can push it up and down, but can't tunnel under it or move the surface sideways.

Any hole you make by lowering terrain will always have sides that slope outward from the base of the hole. Never inward, never exactly vertical.

To make a "basement" under a building, you have to terraform a hole, and build your room(s) inside the hole with prims, then cover the top of the hole with your building or with other prims.

The other approach you can make is put the "inside of the cave" in a skybox, and make the cave entrance a sit-teleport to the skybox using WarpMove.

I put a storm-water culvert that led into a skybox in one build, back around the 1.7 or 1.8 timeframe, and since then I've seen a number of quite elaborate "skybox cave" designs.

Edit: Torley put up a photo of the entrance here: . The culvert in the foreground led to another entrance on the other side of the hill using one sit teleport, and to a skybox using another. The sit teleport was just a hack while waiting for them to release llTeleportAgent (it was in 1.8 or 1.9 beta, I forget which), but I abandoned this approach after they nerfed llTeleportAgent and replaced it with llMapDestination... long range sit teleports are unpleasant. Now that WarpMove works well this kind of approach is more practical again.

I used this approach to make a large cave under a mountain home. You can even add a sculpted plane for a roof to give the illusion of it being a natural cave. If you are trying to do this on mainland there are limits to the degree of terraforming you are allowed. Also keep in mind the if you lower the terrain below sea level you will end up with an underwater habitat .

The only part I don't like about my cave is that instead of looking dark all the time as a cave should it reacts sunlight just as a house above ground .