Hi Laurel,

There is no direct NN=1 value for the renderer. As you have seen,
the rmm (radius in mm) value controls the cluster connections.

If the voxels are isotropic, then rmm=voxel size should give the
same results as NN=1. However if the voxels are 2x2x4, say,
then the render cannot do NN=1 (for example, rmm=4 to get the
slice direction results in not only within slice diagonals, but includes
skipping voxels within a slice).

Note also that vmul (the volume in microliters) equals the number
of voxels times the volume of one.

If you state your voxel dimensions, that would make it easier to
give a specific response.

- rick