This prickly sphere looks amazing in 3D, you can lose your self for hours playing and being mesmerized by it. It doubles as an acupuncture ball, roll it around on your body ( I love it on my head) to relax and circulate your blood, the skin feels tingly afterwards.
I used the 2D wave equation to generate the top surface of this tile. Random oscillators drive waves across the surface, reflecting from the edges and interfering as they cross each other. Like the ripples in a pond that it's designed to mimic I think it's beautiful, I hope you do too.