an illusion with a flat surface that looks like a staircase.

illusion flat surface staircase optical perception visual steps escher geometry pattern perspective depth dimension impossible stairs paradox art trompe-l#39aph39#oeil 3d drawing lines angles shading shadows trick eye realism cubes architecture abstract ascent descent movement gradient symmetry distortion visual-trick deception geometry-illusion escher-style paradoxical infinite recursion perception-shift optical-illusion impossible-stairs visual-effects conceptual impossible-object art-illusion