Issue retrieving positional data from array

Hi team,
I have an issue relating to correctly retrieve data from an array.
I stored positional data (x,y,z) from an object geometry that has child geometry .

the array is created:
var objectMidpoints=[];

i store the position (midpoint of each child geometry) by:


this happens in the loop of :

object.scene.traverse( function ( child ) {

              if ( child.isMesh ) {  


when i run the page and inspect the data is stored in the objectMidpoints[] array

though when i want to access the data to draw spheres on those midpoint positions i fail to access the array correctly. currently i try to access it by using a for loop :

sphereX.position.set( 12, 10, objectMidpoints[i].y );

This is failing, some pinpointers of how to access the datapoints from teh array correctly would be of great help.

Please show what you are trying to do with a live example: