GridPlot 3d isosurfaces don't support supercells

[pfebrer]

I need to find a clever way to tile isosurfaces (i.e. calculate the isosurface once in the unit cell but then repeat its display through all the supercell). The main problem is probably at the cell borders.

[pfebrer]

For the moment, this is solved by tiling the grid first. Supercells can be visualized, but unnecessary computation is done. Keeping this open for the moment until there is a smarter way to handle it or I decide that the extra computation is fine.