You could use a scratch variable here. We try to minimize object allocations. You can declare `var scratchMeanPoint = new Cartesian3();` outside of this function and replace the code here with:

`var meanPoint = Cartesian3.clone(Cartesian3.ZERO, scratchMeanPoint);`

The code that uses `meanPoint` below wouldn't have to change and there is only one allocation no matter how many times this function is called.