Pebble-plate like louvre with specific domain characteristics

A louvre unit comprising a plurality of louvre cells for beam shaping a lighting unit light, wherein the plurality of louvre cells comprises a plurality of n subsets each comprising a respective plurality of m louvre cells, wherein the louvre cells of each subset are configured as a domain of adjoining louvre cells, wherein a respective plurality of k louvre cells within each domain have mutually differing louvre cell cross-sections, wherein 3≤n≤100000, wherein 5≤m≤21, and wherein 5≤k≤m,

• wherein the louvre cells are formed as polygons bounded by a number Ne of louvre walls closing in a loop, wherein for each louvre cell the number Ne is in the range of 3≤Ne≤10,
• wherein the plurality of louvre cells within the same domain only have C1 symmetry relative to a central point in said domain and each domain comprises at least three polygons of incongruent shape, and
• wherein each louvre cell has a respective equivalent cross section, said equivalent cross section being a cross section of a circle having the same cross sectional area as the polygonal shape of the louvre cell, and wherein a ratio between equivalent cross-sections of louvre cells is in the range of 1:2.5.