to surfacetest perspective r=200 setpc "red setLightSpecular "white setMaterialSpecular "white setMaterialShininess 5 ht SurfaceStart for [z -1 1 0.1] [ pu setPosXYZ (list -1 (cos 90*-1)*cos 90*z z)*r pd for [x -1 1 0.1] [ setPosXYZ (list x (cos 90*x)*cos 90*z z)*r ] SurfaceColumn ] SurfaceEnd rotatescene end