llGetGeometricCenter

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Summary

Function: vector llGetGeometricCenter( );

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

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.

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Examples

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

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.

See Also

Functions

•  llGetCenterOfMass

Deep Notes

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;
}

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   Provide better llGetGeometricCenter function.

Signature

function vector llGetGeometricCenter();

Haiku

With each added prim
away shifts our origin
to encompass all.