generate one "plane" of cells after the other to avoid cache thrashing when exporting from virtual stacks
generate one "plane" of cells after the other to avoid cache thrashing when exporting from virtual stacks

bogovicj/bigdataviewer-core,bogovicj/bigdataviewer-core,bigdataviewer/bigdataviewer-core,bigdataviewer/bigdataviewer-core