"7dot-horizontal-hexagon-text-matrix-7x7x7-model-by-dpla-in-2018-as-isometric-colored-spheres-over-5x5x5-black-cube-2048x2048-tr-bg.png"

So, with a 7x7x7 voxel matrix, one can display 8 '7-laid-hex-dot' (eight 7-dot horizontally hexagonal) characters in rotation (shown here), plus 6 '9-orth-dot' characters in another rotation (not shown here, since my own -finished- 3x3 US-ASCII fonts are still unreleased to this day), which would make 14 'micro' characters in a 343-voxel cube-matrix in rotation and partly occupied. B.t.w. you must have noticed the greater number of honeycomb matrices over the common ones (8 vs. 6). The latter fields may be used to provide some extra data too (up to 54 bits in all, or individually to indicate e.g. a direction, checksum, color, material).

dpla 2018-03&04