老问题

raven · 发表于 2002-1-21 17:56:48

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如何判断一点在封闭的pline内.

陈伯雄 · 发表于 2002-1-22 08:46:04

doubao · 发表于 2005-8-13 01:09:34

如何判断某一点是否在一面域内呢？问的也是类似的问题。

最终目标应该是用来点取一个区域。 autocad 的 hatch 里就有这样的功能，但也不能保证完全选取区域成功，因此可以看出这个问题不是那么容易解决的。

青马 · 发表于 2005-8-13 08:28:58

对这条pline求面域，得到这个实体名，再用ssget命令选通过pｔ指定点的面域，两者比较，如果相等，就在内，不等，就在外
这只是我的一个想法，没有编过lisp，我想应该是可行的，完全是借用陈伯雄老师的“cad能完全的事就把事推给cad去作”的思想

leochen · 发表于 2005-8-13 09:43:59

点在PLine以内的话，点与pline线各相邻两点的夹角相加等于2pi

eachy · 发表于 2005-8-13 11:10:04

不完全

doubao · 发表于 2005-8-13 14:03:27

请问“面域”是什么autocad实体？ 3dface？
我觉得4楼的方法应该是最大限度地利用了autocad的已有功能，很不错。

狂刀 · 发表于 2005-8-13 15:24:53

常用求法的有
１射线法（过点任意方向的射线(ray or xline)与曲线的交点个数）
２面积法（即ｒｅｇｉｏｎ求并集进行比较）
３偏移法(过点offset曲线进行比较)
从稳定性上１最佳，２其次，３不推荐

另外有一种，为点到各端点连线夹角求和，但是仅对直线段ｐｌｉｎｅ有效，对复杂一点的曲线无效。

青马 · 发表于 2005-8-13 15:53:48

我刚才试了一下，为什么在ssget行，对面域选择时总是nil啊，为什么总是选不重呢
(defun c:ll () ;if_inter () ;(pt ename)()
  (setq pt (getpoint "\n请输入一点"))
  (setq ename (entsel))
  (command "region" ename "")
  (setq p_region (entlast))
  (setq pt_cross (ssget "_c" pt pt '((0 . "REGION"))))
(boundp (= p_region pt_cross))
)

Underway · 发表于 2005-8-13 17:14:19

Newsgroups: autodesk.autocad.customization
From: "Luis Esquivel" <www.draftteam.com> - Find messages by this author
Date: Tue, 9 Sep 2003 15:46:37 -0700
Local: Wed, Sep 10 2003 6:46 am
Subject: Re: John Uhden's @cv_inside function
Reply to Author | Forward | Print | Individual Message | Show original | Report Abuse

Here is the last update, please let me know if works...:

;;; 3:45 PM 9/9/2003
;;; Luis Esquivel

(defun random ()
(setq seed (if seed
(rem (+ (* seed 15625.7) 0.21137152) 1)
0.3171943)))
(defun get-xy (lst_xyz / cont ints)
(setq cont 0)
(while (< cont (length lst_xyz))
(setq ints (append ints
(list (list (nth cont lst_xyz)
(nth (1+ cont) lst_xyz)))))
(setq cont (+ cont 3)))
ints)
(defun angvec (vect)
(cond
((equal (car vect) 0 0.0001)
(if (minusp (cadr vect))
(* 1.5 pi)
(/ pi 2)))
((equal (car vect) -1 0.0001) pi)
((equal (cadr vect) 0 0.0001)
(if (minusp (car vect))
pi
0))
(T (atan (/ (cadr vect) (car vect))))))
(defun point-inside-polyline
(vla_poly pt aid-pt pts / vla_line lst_value param result)
(setq
result
(cond
;; verifies if the test-point is not on any polyline segment
((and (setq param (vlax-curve-getparamatpoint vla_poly pt))
(eq (type (- param (fix param))) 'real))
nil)
;; verifies if the test-point is not a vertex
((and (not (vl-position (list (car pt) (cadr pt)) pts))
(not
(vl-catch-all-error-p
(setq lst_value
(vl-catch-all-apply
'vlax-safearray->list
(list (vlax-variant-value
(vla-intersectwith
vla_poly
(setq vla_line
(vla-addline
(vla-objectidtoobject
(vla-get-document
vla_poly)
(vla-get-ownerid
vla_poly))
(vlax-3d-point pt)
(vlax-3d-point aid-pt)))
acextendnone))))))))
;; verifies if any of the intersection points
;; is not part of the vertex's
(if (not (vl-some
(function (lambda (i) (vl-position i pts)))
(get-xy lst_value)))
(fix (/ (length lst_value) 3.0))))))
(vl-catch-all-apply 'vla-delete (list vla_line))
(if (and (not
(vl-catch-all-error-p
(setq lst_value
(vl-catch-all-apply
'vlax-safearray->list
(list (vlax-variant-value
(vla-intersectwith
vla_poly
(setq vla_line
(vla-addline
(vla-objectidtoobject
(vla-get-document
vla_poly)
(vla-get-ownerid
vla_poly))
(vlax-3d-point pt)
(vlax-3d-point aid-pt)))
acextendnone)))))))
;; verifies if any of the intersection points
;; is not tangent
(vl-some (function
(lambda (int)
(setq vect
(vlax-curve-getfirstderiv
vla_poly
(vlax-curve-getparamatpoint vla_poly int)))
(equal (angvec vect) (/ pi 2.0) 1.0e-009)))
(get-xy lst_value)))
(setq result nil))
(vl-catch-all-apply 'vla-delete (list vla_line))
(if (numberp result)
(not (zerop (rem result 2)))))
(defun C:TEST-LUIS (/ ent elst pt vla_poly lc uc)
(if
(and (setq ent (car (entsel "\nSelect a polyline: ")))
(eq (cdadr (setq elst (entget ent))) "LWPOLYLINE")
(eq (vla-get-closed
(setq vla_poly (vlax-ename->vla-object ent)))
:vlax-true)
(setq pt (getpoint "\nTest point: ")))
(progn
(vla-getboundingbox vla_poly 'lc 'uc)
(point-inside-polyline
vla_poly
pt
;; remove aid-pt setq - was for testing only
(setq aid-pt (polar pt
(random)
(distance (vlax-safearray->list lc)
(vlax-safearray->list uc))))
;; remove pts setq - was for testing only
(setq pts
(mapcar
'cdr
(vl-remove-if-not
(function (lambda (item) (eq (car item) 10)))
elst)))
))))
(princ)
;;; for plain Lisp ===================================
Newsgroups: autodesk.autocad.customization
From: "Michael Doerr" <mdo...@cebacus.de> - Find messages by this author
Date: 1999/10/27
Subject: Re: Pts inside a poly
Reply to Author | Forward | Print | Individual Message | Show original | Report Abuse
Dennis Healey schrieb in Nachricht <38161DED.7C995...@marin.org>...
>In AutoLISP or Visual LISP (R14) are there ways to evaluate which of
>each of thousands of vertices of lines polylines or arches lay within a
>polyline in 2D space? To be clear, this is different from determining
>if an object is within a select set; I just want to know if a point is
>within a given boundary.
Hi Dennis,
the code below decides quickly wether a given point is inside a boundary. It
decides by checking the angles to the points of the polyline: You have to
call the function "PunktInPolyLinie" by handing over the point you want to
check ("PruefPunkt") and a list of the points of the polyline
("PolyPunkteListe").
Hope this helps, Michael
(defun PunktInPolyLinie (PruefPunkt
PolyPunkteListe
/
)
(if (equal 0.0 (PIPWinkelSumme PruefPunkt PolyPunkteListe) 0.0001)
nil
T
)
)
(defun PIPWinkelSumme (PruefPunkt
PolyPunkteListe
/
Count
P1
P2
Scheitel
WinkelEins
WinkelZwei
)
(setq WinkelEins 0.0
Scheitel (car PolyPunkteListe)
Count 1
)
(while (< 1 (length PolyPunkteListe))
(setq P1 (car PolyPunkteListe)
P2 (cadr PolyPunkteListe)
PolyPunkteListe (cdr PolyPunkteListe)
WinkelZwei (PIPWinkelHilfe PruefPunkt P1 P2)
WinkelZwei (if (< 180.0 WinkelZwei)
(- WinkelZwei 360.0)
WinkelZwei
)
WinkelEins (+ WinkelEins WinkelZwei)
)
(setq Count (1+ Count))
)
(setq WinkelZwei (PIPWinkelHilfe PruefPunkt P2 Scheitel)
WinkelZwei (if (< 180.0 WinkelZwei)
(- WinkelZwei 360.0)
WinkelZwei
)
)
(+ WinkelEins WinkelZwei)
)
(defun PIPWinkelHilfe (PruefPunkt
P1
P2
/
Alpha
Beta
)
(setq Beta (angle PruefPunkt P1)
Alpha (angle PruefPunkt P2)
Alpha (- Alpha Beta)
)
(if (< Alpha 0)
(setq Alpha (+ (* 2 pi) Alpha))
)
(* (/ (float Alpha) pi) 180.0)
)

(defun random  () 
  (setq seed (if seed 
        (rem (+ (* seed 15625.7) 0.21137152) 1) 
        0.3171943))) 
 
 
(defun get-xy  (lst_xyz / cont ints) 
  (setq cont 0) 
  (while (< cont (length lst_xyz)) 
    (setq ints (append ints 
         (list (list (nth cont lst_xyz) 
       (nth (1+ cont) lst_xyz))))) 
    (setq cont (+ cont 3))) 
  ints) 
 
 
(defun angvec  (vect) 
  (cond 
    ((equal (car vect) 0 0.0001) 
     (if (minusp (cadr vect)) 
       (* 1.5 pi) 
       (/ pi 2))) 
    ((equal (car vect) -1 0.0001) pi) 
    ((equal (cadr vect) 0 0.0001) 
     (if (minusp (car vect)) 
       pi 
       0)) 
    (T (atan (/ (cadr vect) (car vect)))))) 
 
 
(defun point-inside-polyline 
       (vla_poly pt aid-pt pts / vla_line lst_value param result) 
  (setq 
    result 
     (cond 
       ;; verifies if the test-point is not on any polyline segment 
       ((and (setq param (vlax-curve-getparamatpoint vla_poly pt)) 
      (eq (type (- param (fix param))) 'real)) 
 nil) 
       ;; verifies if the test-point is not a vertex 
       ((and (not (vl-position (list (car pt) (cadr pt)) pts)) 
      (not 
        (vl-catch-all-error-p 
   (setq lst_value 
   (vl-catch-all-apply 
     'vlax-safearray->list 
     (list (vlax-variant-value 
      (vla-intersectwith 
        vla_poly 
        (setq vla_line 
        (vla-addline 
          (vla-objectidtoobject 
            (vla-get-document 
       vla_poly) 
            (vla-get-ownerid 
       vla_poly)) 
          (vlax-3d-point pt) 
          (vlax-3d-point aid-pt))) 
        acextendnone)))))))) 
 ;; verifies if any of the intersection points 
 ;; is not part of the vertex's 
 (if (not (vl-some 
     (function (lambda (i) (vl-position i pts))) 
     (get-xy lst_value))) 
   (fix (/ (length lst_value) 3.0)))))) 
 
 
  (vl-catch-all-apply 'vla-delete (list vla_line)) 
 
 
  (if (and (not 
      (vl-catch-all-error-p 
        (setq lst_value 
        (vl-catch-all-apply 
   'vlax-safearray->list 
   (list (vlax-variant-value 
    (vla-intersectwith 
      vla_poly 
      (setq vla_line 
      (vla-addline 
        (vla-objectidtoobject 
          (vla-get-document 
            vla_poly) 
          (vla-get-ownerid 
            vla_poly)) 
        (vlax-3d-point pt) 
        (vlax-3d-point aid-pt))) 
      acextendnone))))))) 
    ;; verifies if any of the intersection points 
    ;; is not tangent 
    (vl-some (function 
        (lambda (int) 
 
 
   (setq vect 
          (vlax-curve-getfirstderiv 
     vla_poly 
     (vlax-curve-getparamatpoint vla_poly int))) 
   (equal (angvec vect) (/ pi 2.0) 1.0e-009))) 
      (get-xy lst_value))) 
    (setq result nil)) 
 
 
  (vl-catch-all-apply 'vla-delete (list vla_line)) 
 
 
  (if (numberp result) 
    (not (zerop (rem result 2))))) 
 
 
(defun C:TEST-LUIS  (/ ent elst pt vla_poly lc uc) 
  (if 
    (and (setq ent (car (entsel "\nSelect a polyline: "))) 
  (eq (cdadr (setq elst (entget ent))) "LWPOLYLINE") 
  (eq (vla-get-closed 
        (setq vla_poly (vlax-ename->vla-object ent))) 
      :vlax-true) 
  (setq pt (getpoint "\nTest point: "))) 
     (progn 
       (vla-getboundingbox vla_poly 'lc 'uc) 
       (point-inside-polyline 
  vla_poly 
  pt 
 
 
  ;; remove aid-pt setq - was for testing only 
  (setq aid-pt (polar pt 
        (random) 
        (distance (vlax-safearray->list lc) 
           (vlax-safearray->list uc)))) 
 
 
  ;; remove pts setq - was for testing only 
  (setq pts 
  (mapcar 
    'cdr 
    (vl-remove-if-not 
      (function (lambda (item) (eq (car item) 10))) 
      elst))) 
  )))) 
(princ) 
 
;;; for plain Lisp  =================================== 
 
Newsgroups: autodesk.autocad.customization 
From: "Michael Doerr" <mdo...@cebacus.de> - Find messages by this author   
Date: 1999/10/27 
Subject: Re: Pts inside a poly 
Reply to Author | Forward | Print | Individual Message | Show original | Report Abuse   
 
Dennis Healey schrieb in Nachricht <38161DED.7C995...@marin.org>... 
 
 
 
>In AutoLISP or Visual LISP (R14) are there ways to evaluate which of 
>each of thousands of vertices of lines polylines or arches lay within a 
>polyline in 2D space?    To be clear, this is different from determining 
>if an object is within a select set;  I just want to know if a point is 
>within a given boundary. 
 
 
Hi Dennis, 
 
the code below decides quickly wether a given point is inside a boundary. It 
decides by checking the angles to the points of the polyline: You have to 
call the function "PunktInPolyLinie" by handing over the point you want to 
check ("PruefPunkt") and a list of the points of the polyline 
("PolyPunkteListe"). 
 
 
Hope this helps, Michael 
 
 
(defun PunktInPolyLinie (PruefPunkt 
    PolyPunkteListe 
    / 
   ) 
   (if (equal 0.0 (PIPWinkelSumme PruefPunkt PolyPunkteListe) 0.0001) 
      nil 
      T 
   ) 
) 
 
 
(defun PIPWinkelSumme (PruefPunkt 
         PolyPunkteListe 
         / 
         Count 
         P1 
         P2 
         Scheitel 
         WinkelEins 
         WinkelZwei 
        ) 
   (setq WinkelEins 0.0 
  Scheitel   (car PolyPunkteListe) 
  Count     1 
   ) 
   (while (< 1 (length PolyPunkteListe)) 
      (setq P1      (car PolyPunkteListe) 
     P2      (cadr PolyPunkteListe) 
     PolyPunkteListe (cdr PolyPunkteListe) 
     WinkelZwei     (PIPWinkelHilfe PruefPunkt P1 P2) 
     WinkelZwei     (if (< 180.0 WinkelZwei) 
          (- WinkelZwei 360.0) 
          WinkelZwei 
       ) 
     WinkelEins     (+ WinkelEins WinkelZwei) 
      ) 
      (setq Count (1+ Count)) 
   ) 
   (setq WinkelZwei (PIPWinkelHilfe PruefPunkt P2 Scheitel) 
  WinkelZwei (if (< 180.0 WinkelZwei) 
         (- WinkelZwei 360.0) 
         WinkelZwei 
      ) 
   ) 
   (+ WinkelEins WinkelZwei) 
) 
 
 
(defun PIPWinkelHilfe (PruefPunkt 
         P1 
         P2 
         / 
         Alpha 
         Beta 
        ) 
   (setq Beta  (angle PruefPunkt P1) 
  Alpha (angle PruefPunkt P2) 
  Alpha (- Alpha Beta) 
   ) 
   (if (< Alpha 0) 
      (setq Alpha (+ (* 2 pi) Alpha)) 
   ) 
   (* (/ (float Alpha) pi) 180.0) 
)

doubao · 发表于 2005-8-13 18:58:06

原来“面域”就是 region .

青马 · 发表于 2005-8-13 23:01:13

看看这贴，有源码
http://www.xdcad.net/forum/showthread.php?s=&threadid=410414

雄啸 · 发表于 2005-8-14 23:30:26

判断点在曲线内外，支持所有曲线，制裁1次自相交曲线
命令：ptin

eachy · 发表于 2005-8-15 16:38:07

排除内部线的影响还可以用这个

(equal (vlax-curve-getarea entity) (bpoly point) 0.00001)

复制代码

青马 · 发表于 2005-8-15 17:52:13

版主给看看，为什么我选不重呢，有什么办法吗
(setq pt_cross (ssget "_c" pt pt '((0 . "REGION"))))

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