Lisp mod

[lonie]

I use a lisp that moves a body around a poly line; it does this in a sort of stepped animation. I would like to modify the list so that it leaves body prints behind. Being new to lisps I can't work out how to do this.

I've attached the lisp i use.

The jpg shows what I'm after if I can get a modified lisp to run.

What am I missing ?

mst (ssg).lisp.txt

[NBC]

In that lsp, can't you just substitute Copy in place of Move ?

[lonie]

Tried it, no joy. I think that the last last step is erased as the body is steeped around pline

[lpseifert]

not tested...

try commenting out the erase entlast

and try copy as NBC suggested

[lonie]

Still just steps it around, without leaving a copy.

[CarlB]

I didn't see where the routine uses actual vehicle turning theory (I may have missed it in my quick look). And the path shown doesn't look like what a vehicle would sweep around a turn. The outside rear should not bump out, and there should be more sweep to the inside.

 

The lisp creator should check out the theory and a lisp at:

http://www.hawsedc.com/gnu/turntheo.php

http://www.hawsedc.com/gnu/turn.php

[alanjt]

I 100% agree with Carl. However, maybe that there's another intention. Personally, I've always liked AutoTurn. However, you asked for a fix, so try this (replace this subroutine):

(defun MoveStep()
(repeat (length pL)
   (setq p3 (nth j pL))
   (setq pa3 (vlax-curve-getParamAtPoint cur p3))
   (if (>= (* flag pa3) (* flag pa1))
       (progn
           (command "circle" p3 r) 
           (setq ipL (ints cur (entlast)))
           (if (> (length ipL) 1)
               (setq p4 (getnearP p1 (car ipL) (cadr ipL)))
               (setq p4 (car ipL))
           )
           [color=Red];(command "erase" (entlast) "") [color=Lime]<-commented out[/color][/color]
           (command [color=Red]"copy"[/color] ob "" p1 p3) [color=Lime]<-changed from move to copy[/color]
           (command "rotate" ob "" p3 (rtd (- (angle p3 p4) ag)))
           (setq p1 p3 ag (angle p3 p4))
           (command "delay" 100)
       )
   )
   (setq j (1+ j))
)
)

[lonie]

Hi Carl / Alanjt,

The body is in fact a car shell that is swept / stepped around a conveyor. The two circles inside the body must be constantly on the pline. I use it to explain how a body moves around on conveyors for clash detection.

 

I cut and pasted the mod in with no joy.

[alanjt]

I cut and pasted the mod in with no joy.

 

How ambiguous. Could you not make it work or did it not give you the desired results. The more information you give, the easier it is to help. It copied everything for me.

[lonie]

Have ran the lisp and this is what I get, it does leave a copy but doesn't follow the path.

[lonie]

Finally got it to work, inserted copy after it aligned itself.

Just to close off the thread I've shown the change.

 

Thanks

 

;;;------------------------------------------------------------------------------

(defun moveStep()

(repeat (length pL)

(setq p3 (nth j pL))

(setq pa3 (vlax-curve-getParamAtPoint cur p3))

(if (>= (* flag pa3) (* flag pa1))

(progn

(command "circle" p3 r)

(setq ipL (ints cur (entlast)))

(if (> (length ipL) 1)

(setq p4 (getnearP p1 (car ipL) (cadr ipL)))

(setq p4 (car ipL))

)

(command "erase" (entlast) "")

(command "move" ob "" p1 p3)

(command "rotate" ob "" p3 (rtd (- (angle p3 p4) ag)))

(setq p1 p3 ag (angle p3 p4))

(command "copy" ob "" p1 p3) ;inserted copy after the block is aligned

(command "delay" 100)

)

)

(setq j (1+ j))

)

)

;;;===================MAIN====================