The function to create of polyline

[jan_ek]

Have anyone tried to create a command which draws a polyline according to coordinates of points and the radius of bending? It means that the command draws, for example, a polyline like in attachment, arguments are points marked on yellow and diameter of arch (for example), alternatively there could be also a commend closing polyline.

I have read about the way of counting a radius according to "bulge". I am not sure how I should start - what should be counted into a radius?

I would be very grateful for any help or comments.

[marko_ribar]

Well, if you have all dimensions set, then correct array of dimensions is required in order to get correct array of points - future vertices, and for arced segments I suggest that you use fillet command - it's also required correct array of selected dimensions... But all in all, I would draw that pline manually faster than with possible quirkiness ab obtain correct arrays from sel. sets...

[asos2000]

In case of Rs are equal for Pline we can entmake Pline (attached) then use fillit command

 

(setq obj (entlast))
(command "fillet" "P" "r" 30 obj)

Entmake Min Codes CAB.LSP

[mostafa badran]

try this

(defun c:test ()
 (entmake '((0 . "LWPOLYLINE")
        (100 . "AcDbEntity")
        (8 . "0")
        (100 . "AcDbPolyline")
        (90 . ;Number of vertices
        (10 176.0636632716071 279.6390112374238); 10 =Vertex coordinates (in OCS), multiple entries; one entry for each vertex
        (10 346.0636632716071 279.6390112374238)
        (42 . 0.414213562373095); 42=Bulge (multiple entries; one entry for each vertex) (optional; default = 0)
        (10 376.0636632716071 309.6390112374238)
        (10 376.0636632716071 449.6390112374237)
        (42 . -0.414213562373095)
        (10 406.0636632716071 479.6390112374238)
        (10 568.0354241512509 479.6390112374238)
        (42 . 0.131490546050545) 
        (10 583.0188770098191 483.6487026506627)
        (10 821.2389076067196 620.9829165365836)
        (70 . 0);Polyline flag (bit-coded); default is 0: 1 = Closed;
       )
 )
 (princ)
)                    

HTH

m.badran

[BIGAL]

A slight variation on above the point list could come from somewhere else execl etc.

 

(defun make_sq ()
(setq vertexList (list 
(list -3.25 -3.25 0.)
(list 3.25 -3.25 0.)
(list 3.25 3.25 0.)
(list -3.25 3.25 0.)
))
(entmakex
(append 
(list '(0 . "LWPOLYLINE") 
'(100 . "AcDbEntity")
'(100 . "AcDbPolyline")
(cons 90 (length vertexList))
(cons 70 1)  ; 1 closed : 0 open
(cons 8 "0")
(cons 38 0.0)
(cons 210 (list 0.0 0.0 1.0))
)
(mapcar '(lambda (pt) (cons 10 pt)) vertexList)
)
)
)