Why does an object rez up in the air?

I've had this happen with items I've bought, and now on a sculpt I made, it's the same thing...you rez it, and it's way high in the air.

Why does this happen and how do I fix it?

Thanks, Nic

it happens with cut prims too has to do with collision box
i use a script to move it down on_rez

// on_res move down 

vector down = <0,0,-0.517>; //distance to movedown use negative for down z axis

vector pos;

default {
    on_rez(integer start_param) 
    {
        pos = llGetPos();
         llSetPos(pos + down); 
    }

}
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Oh, thank you!!!

Edit: works PERFECTLY!

I hadn't thought of that, nice script

Has anyone else tried that script when rezzing an object on a prim floor? It seems to drop it right down through the prim.

I was rezzing on my work platform, which is basically a giant floor in the sky. Had no problem, although you do have to tinker with the value. Trial and error on that.

It's interesting though, even when I rez an ordinary prim like a cube or a sphere (no script), it rezzes higher above the ground than it does above a flat prim surface. Makes it hard to find a value that works for both situations.

Well, duh. The Z-value of -0.517 is quite arbitrary. It's simply a little more than half the thickness of a one meter prim. If you use something other than a 1m thick prim, of course you have to vary the Z value.

Here's the slight variation I use on my furniture and other builds that need this sort of adjustment. It works perfectly on prim surfaces as well as on the ground, and has been tested to at least 3,000 Meters. You alter the "adjustHeight" variable to indicate how much to move the item up or down, in Meters, from where it rezzes initially. So for example if you used a cut cylinder for the bottom of a chair, and the cylinder was 1 M tall on the Z-axis, an adjustHeight value of -0.5 would move the linkset down 1/2 meter an instant after it rezzes, placing the chair at the midpoint of that cylinder


// adjust this height
float adjustHeight = -0.2; // how much the position should be adjusted when the object is rezzed. (m) -

default
{
on_rez(integer x) {
vector v = llGetPos ();
v.z = v.z + adjustHeight;
llSetPos(v);
}
}

If you don't like typing a new Z value every time you use the little script in a new object, you can always modify the script to calculate its own Z-value. So long as you haven't rotated your object so that its Z-axis is non-vertical, for example, this small modification works ....

// on_res move down 1/2 of the prim's height (if its Z axis is vertical)
default {
on_rez(integer start_param) 
{
vector primSize = llGetScale();
vector down = <0,0,-(primSize.z/2.0)>;
vector pos = llGetPos(); 
llSetPos(pos + down); 
}
}

ETA: Ha! Ceera beat me to it. Well, now you have two versions....

Three versions, Rolig. Mine is closer to the original one posted, as it doesn't try to calculate the offset. The main advantage of mine is you only enter a scalar Z-value, and not an <x,y,z> vector, for the adjustment.