The images of the tree in snow were created by a six-fold rosette transformation (that is a complex function which is the sum of six function of identical form centred around six different locations spaced around a hexagon. I was trying here to create a visual references to the structure of snow crystals, so looked for a fairly high degree of symmetry, selecting harmonics that emphasised the six-fold rotational symmetry (and sometimes deliberately broke it).
All images are copyright Michael McEllin and are low-resolution versions of the higher-resolution originals intended for printing.