with regards to mc01.jpg...mc24.jpg
 https://github.com/martijnberger/blender/tree/master/release/datafiles/matcaps
 These matcap images are licensed as GNU GPL 2 or later, like the rest of Blender's code.
 Thanks to Kent Trammell, Aidy Burrows, John Herreno , Terry Wallwork and David Silverman for making the pictures.

with regards to fubax.jpg
 https://github.com/Fubaxiusz/fubax-shaders/blob/master/Textures/matcap.png

Porcelain from
 https://threejs.org/examples/webgl_materials_matcap.html
