如何建立圆形选择集

zhuxuhong

已知图上有一个圆,如何求得与该圆相交的所有实体?

天下第三

用折线模拟圆,然后ssget "wp" "cp" "f"

oyxx1023

楼上办法不好。打折的。

可以这样，先得到CIRCEL的boundingbox，ssget　by cross(设置过滤条件，点表用刚才得到的BOX顶点坐标)，，再遍历得到的选择集和圆求交，有交点的添加到新的选择集。

图形文件不大的话直接全部与其求交得了。

byghbcx

看了几天了,还是手写一个实用的园形选择集吧

(defun circle_select (/ loop pt_tmp pt_list pt pt1 source pt2 ss)
  (initget 1)
  (setq pt1 (getpoint "\n first point:"))
  (setq loop t)
  (setq pt_tmp '(0 0 0))
  (while loop
    (setq pt (grread t 4 0))
    (setq source (car pt)
   pt2  (cadr pt)
    )
    (cond
      ((and (= source 5)
     (or (/= (car pt1) (car pt2))
  (/= (cadr pt1) (cadr pt2))
     )
       )    ;end and
       (if (/= pt_tmp pt2)
  (progn
    (drawcicle pt1 pt_tmp 0)
    (drawcicle pt1 pt2 256)
  )
       )
      )     ;end first
      ((or (= source 3)
    (and (= source 2)
  (or (= pt 13) (= pt 32))
    )    ;end and
       )    ; end or
       (setq loop nil)
       (drawcicle pt1 pt2 0)
      )     ; edn second
      ((and (= source 2) (or (= pt 89) (= pt 121)))
       (setq loop nil)
      )     ;end third
    )
    ;;end cond
    (setq pt_tmp pt2)
  )
  ;; edn while
  (setq pt_list (list (polar pt1 (* (/ pi 4) 0) (distance pt1 pt2))
        (polar pt1 (* (/ pi 4) 1) (distance pt1 pt2))
        (polar pt1 (* (/ pi 4) 2) (distance pt1 pt2))
        (polar pt1 (* (/ pi 4) 3) (distance pt1 pt2))
        (polar pt1 (* (/ pi 4) 4) (distance pt1 pt2))
        (polar pt1 (* (/ pi 4) 5) (distance pt1 pt2))
        (polar pt1 (* (/ pi 4) 6) (distance pt1 pt2))
        (polar pt1 (* (/ pi 4) 7) (distance pt1 pt2))
  )
  )
  (setq ss (ssget "_wp" pt_list))
  (sssetfirst nil ss )
  (princ)
)

(defun drawcicle (pt1 pt2 k / m)
  (grdraw pt1 pt2 k)
  (setq m 30)
  (while (> m 0)
    (progn (grdraw (polar pt1 (* (/ pi 15) (- m 1)) (distance pt1 pt2))
     (polar pt1 (* (/ pi 15) m) (distance pt1 pt2))
     k
    )
    (setq m (- m 1))
    )
  )
)

龙龙仔

說過很多次了,express tools中有 'FS & 'FSMODE 指令

Creates a selection set of objects that touch the selected object.

The behavior of FASTSELECT can be controlled with the command FSMODE. If FSMODE is set to ON (the default), FASTSELECT selects only those objects that are touching the selected object. When FSMODE is OFF, FASTSELECT selects all the objects that are touching the selected object as well as any objects that are touching those objects. The command continues down the chain of unselected objects that are touching the selected object until no more unselected objects are visible on screen.

Note:
FASTSELECT selects only lines, polylines, lightweight polylines, circles, arcs, attribute definitions, text, mtext, ellipses, and images.

Tip:
You can use FASTSELECT at the command line and (transparently) in many commands.

Command: 'FS
Select touching object: Select an object

Command: 'FSMODE
FASTSEL chain selection <OFF>: Enter ON or OFF

oyxx1023

请问楼上，如何把FS用到程序中？

phoenixdjq

在安装cad的时候添加，cad安装程序有这个选项的

龙龙仔

(defun C:TT (/ SS)
  (C:FS)
  (command "_.ERASE" "P" "")
  (princ)
)