startshape k background { b -.8 } rule k {10*{r 79 x 3 s .8}cube{h 200 sat .7 b .3}} rule cube{ m { s cos(75) 1 r 50} } rule sq1 {SQUARE [ s tan(75) sin(25) x -.5 y .5 ] } rule sq2 {SQUARE [s tan(75) cos(25) x -.5 y -.5] } rule sq3 {SQUARE { x .5 y -.5} } rule m { sq1 { skew (90-25) 0 b .5 } sq2 { skew (-25) 0 b .6 } sq3 { r 25 b .7} } // You may change the angles 75, 25 and 50 // 0 < alfa < 90 // 0 < beta < 90 // alfa = 75 // beta = 25