Underground buildings.

As a feature request it would be really neat to be able to build below ground level. I know that it's possible to place objects below ground level since I have done it accidently. Note: It's hard to get them back.

The simplest option would be it make it so that if you are more than 10 meters below ground level; the ground is tuned off and you would fall to 0. You can fly up threw the ground, but not down threw it.

Edit:
The sim could also "jump" the person back to ground level on a property boundary. We don't want people flying around underground.
Or mabe we doo... Zork and the great underground empire.
END edit:
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Another method would be to have the teleporter set some setting that allows the avatar to ignore the ground.

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Background:

The sky's are crowded due to the fact that you can't teraform deep enough to add private basements. So we add big boxes in the sky and teleport into them.

I had another person fly into my "basement" skybox again.
The problem is that they are flying too fast for all objects to load and thus my skybox just materized around them.

if I could build the rest of my house under ground I would not have to worry about people flying into it, Mouselooking into it, Sit jumping threw the walls, ect...

Edit:
Acceptable side affects.
1. The ground is probably a single sided object and thus would not appear when looking up. This is not a problem as long as you add a ceiling.
2. Water would still be there. You could even make underground rooms using the water.
3. The sun and shadows would still appear. Just set "Full bright" and then adjust the color.

Edit Code thoughts:

Existing. (I am guessing)
if (avitarPos.z < groundHeight )
{
AvitarPos.z = groundHeight;
};
Change to
if ((avitarPos.z < groundHeight ) && (avitarPos.z > (groundHeight - 10)))
{
AvitarPos.z = groundHeight;
};
// The compiler will only execute the the -10 and compare if the first is true.

I'm going to make another asumptiuon and say that the ground shape is probably a grey scale bit map with about one pixel per meter.

If so... It would be possible to make an invalid setting to make holes in the ground for stairs, caves, tunnels.

Sim Code
if (groundHeight != GROUND_INVLALID)
{
//Insert above height checking
};

Unfortantly this feature would also require a Viewer upgrade

if ((groundHeight(x,y) != GROUND_INVLALID)
&& (groundHeight(x+1,y) != GROUND_INVLALID)
&& (groundHeight(x,y+1) != GROUND_INVLALID)
&& (groundHeight(x+1,y+1) != GROUND_INVLALID) )
{
//Interpolate and draw polygon (x,y) to (x+1,y+1)
};


Note: I chose 10 meters in the above post to prevent crashing threw the ground due to high velocity impacts.

Acceptable side affects.
1. When making a cave or tunnel you would have to remove the ground above the entrance an additional 10 meters and then cover the hole with a prim.

How deep do you want to be able to terraform?

I would LOVE to be able to set a patch of ground to "phantom", so I could build under ground like I can build under water, but that's purely for aesthetic reasons. I haven't run into terraform problems in the Islands. llSay() is limited to 20m and I've certainly dug a hole 20m deep before. Heck, I've got one right now that's about 22m from the highest to the lowest point.

The sim I am on has a teriform limit.
And even if it didn't; I don't want to have to cover my entire property with prims.

I just want to use the area between 30 meters and 90 meters for my club's private rooms. They are currently in the sky at at 230 meters and 360 meters.

I feel the sim change is very simple to let people (sit style) teleport down there.

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I don't think a "Phantom" option would be easy since that would require an extra bit per SQ meter. The "Invalid" option would make the ground disappear without adding any extra memory requirements. but I consider this a bonus feature that would take longer.

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I see this as a solution to a hole list of other issues.
1. Flying into closed skyboxes.
2. Keeping private areas private.
3. Mouse looking into private areas.
4. Cluttered skys.

Edit:
I would set GROUND_INVLALID to zero since once the ground is at zero It's soo dark that it really does not matter if it's drawn by the graphics engine provided that black is applied at the start of the frame build.

I noticed
http://secondlife.com/tiki/tiki-index.php?page=RawTerrainFile
It says there are 13 channels and looking at the format it wastes a lot of bits.

But this is probably just be an intermediate format and not how it's stored internally.

So there may be an extra bit for your "Phantom" concept.
An "Invisible" could also be possibly implemented.

Steady on, Buck! That would use up an additional 8k of RAM per simulator! o_O!

/13/a9/39675/1.html

I'd have loved to be able to build underground too.

I did an underground build in SW Aglia, topped it off with prims textured using the Library atoll textures. Came out pretty nice. I sold it to kat Lemiuex a few weeks ago, but i'm sure it's still there.

Knock first

In Chaos I have 1.25 kilometers of cave and tunnel underground (linear distance) as well as some ruins of a city, a small club and... well it's a long list... much of it is below the water table.

in a sim called Fate there is an entire underground base that's pretty hi-tech looking, good stuff!

It's already possible, unfortunately not every sim is as teraformable as the one you are currently in by the sounds of it.

The Wiki has a list of sims and their teraform limits someplace.....

most sims are 4m +- whatever the original ground shape was
I have an area that lets you dig 1m, and at the other end its almost 8m down from level, i would take that if it was bigger than 3mx5m