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llGetGeometricCenter

vector llGetGeometricCenter()

Returns the vector that is the geometric center of the object relative to the root prim.

Technical Details

Return Type: vector
Energy: 10

default
{
    touch_start(integer total_number)
    {
        llOwnerSay("Geometric center of the object relative to the root prim: " + (string)llGetGeometricCenter());
    }
}

Caveats

The “geometric center” is different from the “center” in viewer’s build tools and also different from what llRezObject considers to be the “center” of a linkset.

Notes

The “geometric center” is the average of all linked prim centers. Mathematically, it’s the root-relative positions of all linked prims in the linkset added together and divided by the number of prims in the linkset.

Implementation Details

vector GetGeometricCenter(){
    vector center = ZERO_VECTOR;
    integer p = llGetNumberOfPrims();
    //since we skip the root prim, we can ignore the single prim case.
    //If we weren't skipping the root, this would be more complicated.
    integer i = 1;
    while(i < p)
        center += llList2Vector(llGetLinkPrimitiveParams(++i, [PRIM_POS_LOCAL]), 0);
    return center / p;
}

See Also

llGetCenterOfMass