将图形向上然后向下移动，如果移动的距离足够大，超出了autocad的可处理范围，autocad会将图形z坐标置为0 源码： ``` (command "move" (ssget "x") "" "0,0,0" "0,0,1e99") (command "move" (ssget "p") "" "0,0,0" "0,0,-1e99") ```