Polyline with offset

[devitg]

Good work Marko 

Tanks for the so simple and effective LISP .

 

[lrm]

Here's a version that requires only 3 points, the front two corners of the desk and any point along the back edge of the desk.

u12 is a unit vector from p1 to p2

u43 is a unit vector from the projection of p3 onto line p1 p2 to p3.

 

(defun c:mike2 (/ p1 p2 p3 p4 p5 p6 d e f h osm u12 u43)
; lrm  6/4/2019  
  (setq	p1  (getpoint "\nFront desk corner: ")
	p2  (getpoint "\nOther front desk corner: ")
	p3  (getpoint "\nA beck desk corner: ")
	osm (getvar "osmode")
  )
  (setvar "osmode" 0)
  (setq	d   (distance p1 p2)
	u12 (mapcar '/ (mapcar '- p2 p1) (list d d d))
	e   (dot (mapcar '- p3 p1) u12)
	p4  (mapcar '+ p1 (mapcar '* (list e e e) u12))
	f   (distance p3 p4)
	u43 (mapcar '/ (mapcar '- p3 p4) (list f f f))
	h   (+ f 800.0)
	p5  (mapcar '+ p2 (mapcar '* u43 (list h h h)))
	p6  (mapcar '+ p1 (mapcar '* u43 (list h h h)))
  )
  (command "_.pline" "_non" p1 "_non" p2 "_non"	p5 "_non" p6 "c")
  (setvar "osmode" osm)
  (princ)
)
(defun cross (a b / crs)
  (setq	crs (list
	      (- (* (nth 1 a) (nth 2 b))
		 (* (nth 1 b) (nth 2 a))
	      )
	      (- (* (nth 0 b) (nth 2 a))
		 (* (nth 0 a) (nth 2 b))
	      )
	      (- (* (nth 0 a) (nth 1 b))
		 (* (nth 0 b) (nth 1 a))
	      )
	    )				;end list
  )					;end setq crs
)					;end cross

;;; dot product of 2 vectors a and b
(defun dot (a b / dd)
  (setq dd (mapcar '* a b))
  (setq dd (+ (nth 0 dd) (nth 1 dd) (nth 2 dd)))
)

 

[BIGAL]

Nice Lrm that's what I was thinking off the unit vector, as the request is to include random objects so just need the square off point.

 

A maybe rather than hard code + 800 a getreal with default of 800. That way will work with other offsets.

 

 

(setvar "osmode" 0)
(if (not AH:getvalsm)(load "Multi Getvals.lsp"))
(setq off (atof (nth 0  (AH:getvalsm (list "Offset plines " "Offset distance" 5 4 "800")))))
(setq	d   (distance p1 p2)
......
......
h   (+ f off)

 

Multi GETVALS.lsp