load =1mdm
define set1 *.O?' and dna
define set2 *.OP? and dna
define set3 *.N? and dna
pause

resume
restrict dna
spacefill off
pause

resume
select set1
spacefill 100
pause

resume
select set1
spacefill off
select set2
spacefill 100
pause

resume
select set2
spacefill off
select set3
spacefill 100