Welcome Chris,
do we have a growing quantum dot community here :smile:
Midnight is approaching here and my pillow is already calling,
so I will advance with the next steps already.
If finally the grid is populated with tetrahedrons, this whole particle thing needs to be turned into a single object by particle>polygon command.
Now we select all polygons and duplicate (copy - paste) them and then move those above the original array.
In order to snap them to the tips of those beneath, one must double-click on the little ball in the center of the transform tool so it gets blue.
Then click on the outer point of the front edge tetrahedron and the transform gadget will stick there; double-click middle again to leave the gadget mode.
Now snapping to components is to be activated in the transform tool properties.
Dragging by the transform center to the tip of the bottom edge tetrahedron will align the copied tetrahedron array nicely on top of the original one, all within the same object, just by manipulating duplicated polygons.
There will now be three rows of overhang polygons on the other side of the object which can be deleted (area select in point mode recommended).
The Optimize Tool needs to be applied to weld all points together (otherwise doubled points in the same place will cause problems later when we assign balls to them with a particle mesh).
This procedure of doubling the array and dragging-snapping it on top of the other has to be repeated until the whole upper half is completed, and then the bottom half too (or maybe use symmetry for that).
I will stop here for today and meet you guys again tomorrow!