请问，如何求某一点到一pl线的距离

matichen

matichen

matichen

chg

1.在CAD状态下可以直接用dist命令。
2.在程序当中，先求得PL线的两个端点，然后过指定点做它的垂线，取得
交点，再求出距离。(如果PL线是圆弧，我也没有办法)

曙光一号

(defun c:dis()
  (setq xtbl (getvar "osmode"))
  (setvar "osmode" 39)
  (setq pot (getpoint "\n 请选择点")
        xian (car (entsel "\n 请选择直线"))
        pt1  (cdr (assoc 10 (entget xian)))
        pt2  (cdr (assoc 11 (entget xian)))
        ang1 (angle pt1 pt2)
        ang2 (angle pt1 pot)
        ang3 (- ang2 ang1)
        dis1 (distance pt1 pot)
        dis2 (* (cos ang3) dis1)
        pt3  (polar pt1 ang1 dis2)
        dis3 (distance pot pt3)
        )
  (setvar "osmode" xtbl)
  (princ "\n 点到直线的距离是：")
  (princ dis3)
  (princ)
  )

南子

matichen

alin

I don't really catch your question. But if you can get it via exploding it, of course you can get it by extracting all the data from the lWPOLYLINE.

Use ENTGET you can get all the vertice's coordinates and (for arc) the bulge value, which is is the tangent of 1/4 of the included angle for the arc between the selected vertex and the next vertex in the polyline's vertex list.

龙龙仔

龙龙仔

;;测试版:一点与线的最短距离
(defun C:TEST (/ SS STARTPOINT ENDPOINT QQ WW PT)
  (setq SS (car (entsel "\n选择线: ")))
  (setq WW (getpoint "\n选择点: "))
  (setq        STARTPOINT
         (vlax-curve-getstartpoint
           (vlax-ename->vla-object SS)
         )
  )
  (setq        ENDPOINT (vlax-curve-getendpoint
                   (vlax-ename->vla-object SS)
                 )
  )
  (setq        QQ (vlax-curve-getclosestpointto
             (vlax-ename->vla-object SS)
             WW
           )
  )
  (if (or (equal QQ STARTPOINT)
          (equal QQ ENDPOINT)
      )
    (if        (> (distance WW STARTPOINT) (distance WW ENDPOINT))
      (SETQ PT ENDPOINT)
      (SETQ PT STARTPOINT)
    )
    (progn
      (command "_.line" WW "per" QQ "")
      (command "_.erase" (entlast) "")
      (SETQ PT (getvar "lastpoint"))
    )
  )
  (COMMAND "_.LINE" WW PT "")
  (COMMAND "_.CIRCLE" WW PT)
  (DISTANCE WW PT)
)