Voronoi 2D patterns

One of the frequently seen mathematical patterns in nature is the Voronoi pattern whose 4  variations can be downloaded on this page. This pattern is also called a Voronoi tessellation, Voronoi decomposition and Voronoi partition. It is named after the Russian mathematician Georgy Voronoi.
In mathematics, a Voronoi diagram is a method of partitioning a plane into regions whicht are called Voronoi cells. It is very easy to make a Voronoi pattern. Scatter randomly points on a plane, connect each point with a line to another point that is at its closest distance, and then bisect each of these lines with a perpendicular. After these lines are trimmed, you will get a Voronoi pattern. 
The Voronoi pattern and various similar mathematical patterns can be surprisingly often seen in nature: on a giraffe’s body, a dragonfly’s wings, seed pods ... A huge number of Voronoi patterns and its variations in nature can be identified when seen through the microscope at the cellular level. All four Voronoi patterns that you can download here are drawn in Rhinoceros 3D CAD software using Grasshopper plug-in. The Voronoi pattern can also be applied to 3D surfaces; on page Topological mesh modeling examples converted to NURBS surfaces, you can see and download (Voronoi sphere 3D model) for free a Voronoi pattern that is applied to a sphere in the form of opening.?
All the Voronoi patterns available on this page are under Creative Commons CC0 1.0 Universal Public Domain Dedication license.
In addition to 2D CAD (.dwg) file format, vector (.eps and .svg) file formats exported from CAD program are also available for download.