I made another shader in Shadertoy. Two triangles are rendered using a webgl fragment shader showing an abandoned base. The scene is rendered by ray-marching a distance field and features dynamic lights, soft shadows, reflections and ambient occlusion.
Last year I read an article describing the mathematical structure of Escher’s Print Gallery. Escher’s Print Gallery (de Prentententoonstelling in Dutch) shows a man standing in an exhibition gallery, viewing a print of a seaport.