new
gen zone brick p0 0 0 -10 p1 20 0 -10 p2 0 1 -10 p3 0 0 0 size 20 1 10 group clay
gen zone brick p0 20 0 -10 p1 40 0 -10 p2 20 1 -10 p3 20 0 0 ratio 1.1 1 1 size 12 1 10
group clay
gen zone brick p0 0 0 0 p1 20 0 0 p2 0 1 0 p3 0 0 6 p4 20 1 0 p5 0 1 6 p6 11 0 6 p7 11 1 6
size 20 1 12 group dam
sel geogrid range x 7 30 z 7.99 8.01
sel node init zpos add 2 range z 7.99 8.01
sel geogrid range x 7 20 z 7.99 8.01
sel node init zpos add 4 range z 7.99 8.01
sel geogrid range x 7 15 z 7.99 8.01
sel node init zpos add 8 range z 7.99 8.01
请问命令流里面sel node init zpos add 8中
range z 7.99 8.01 是什么意思