💡📝Larry Smith wrote on Sun, Aug 30, 2009 06:01 PM UTC:
Just a little history of planar pieces.
In 1997, D.E. Matson simply named the 3D planar pieces; 3D Rook(orthogonal), 3D Bishop(diagonal) and 3D Queen(orthogonal/diagonal).
In 2004, Prince was published at TCVP.
And in 2004, LiQi was published at the Zillions-of-Games site.