ZXASCII
AUTO -1
PROG reliefmap
10 GRAPHIC new img load "demos:3d/horse.png"
20 PAPER 0: INK 15: CLS 
30 DIM h(scrw) base 0: mat h()=con scrh
40 FOR y=scrh-1 TO 0 steP -2:
    FOR x=0 TO scrw-1:
       y1=y-(gpoint(img,x,y)/2): 
       IF y1<=h(x) THEN 
          h(x)=y1:
          PLOT x,y1:
90    NEXT x:
 NEXT y