Box adaplate aggregation to a Brep!

Hello,

I have a question and i have tried anything but nothing come up. I want to do a small pavilion with aggregation of boxes (all in the same size) but the tricky part is that i have the inner area (a brep like a sphere etc.) and the and when i reduce the area the cubes adapate to the form but never lose the total number of cubes , thus obtaining different forms of construction of the object.

I made a definition that calculates the distance of a 3D grid of points to the exterior points in these exterior points growth multiple boxes, but it's not quite what I intend, i wanted something that with the same number os boxes is adaptable to diferent geometries.

Can you please help me!

Thank you so much in advance.