end result will look something like this but it will be a line? polyline?
I got some progress by converting an arc into polyline and use pedit to give it width
but i couldn't figure out how to make it so that it will not be filled in
how do I create line/curve that basically looks like a pipe?
not what I am looking for.
i just need to create something like this on a daily basis
i would like the pipe to be easily mutable in all directions basically. and i basically want it to be 1 singular arc that i can just drag and drop the ends and be done with it.
@Simon_Weel wrote:
Maybe a Multiline ?
... if it can be of only straight-line segments. And of course the "cut" end part would need to be in addition.
Kent Cooper, AIA 
I'm not sure if the following does something close to what you want. The user specifies a pipe diameter and a series of spline fit points and the program create two offset splines with ellipses at the ends.
The user can trim one of the ellipses if desired.
The program does not indicate the spline fit point as they are being specified and it uses the start point to select the orignal spline. This could cause a problem in certain circumstances. Improvedments to the code are welcomed.
Lee
;;(defun c:splinepipe (/ dia r p more spl slope perslope smax pStart pEnd p1 p2 p3 )
(defun c:splinepipe (/ )
; Creates offset spline with eliipses at their ends for a series of
; user specified spline fit points.
; L. Minardi 9/24/2024
(setq dia (getreal "\nEnter pipe diameter: ")
r (/ dia 2.)
p (getpoint "\nEnter spline start point: ")
more T
)
(command "_spline")
(while more
(command p)
(setq p (getpoint p "\nEnter next spline fit point: "))
(if (not p)
(setq more nl)
)
)
(command "" "" "")
(setq spl (entlast)
slope (unitvec (vlax-curve-getfirstDeriv spl 0))
perslope (list (cadr slope) (- (car slope)) 0.0)
smax (vlax-curve-getEndParam spl)
pStart (vlax-curve-getPointAtParam spl 0)
p1 (mapcar '+ pStart (mapcar '* perslope (list r r r)))
p2 (mapcar '- pStart (mapcar '* perslope (list r r r)))
p3 (mapcar '+
pStart
(mapcar '* slope (list (/ r 2) (/ r 2) (/ r 2)))
)
)
(command "_offset" r pStart "_non" p1 "")
(command "_offset" r pStart "_non" p2 "")
(command "_ellipse" "_non" p1 "_non" p2 "_non" p3)
(setq
slope (unitvec (vlax-curve-getfirstDeriv spl smax))
perslope (list (cadr slope) (- (car slope)) 0.0)
pEnd (vlax-curve-getPointAtParam spl smax)
p1 (mapcar '+ pEnd (mapcar '* perslope (list r r r)))
p2 (mapcar '- pEnd (mapcar '* perslope (list r r r)))
p3 (mapcar '+
pEnd
(mapcar '* slope (list (/ r 2) (/ r 2) (/ r 2)))
)
)
(command "_ellipse" "_non" p1 "_non" p2 "_non" p3)
(command "_erase" spl "")
(princ)
)
; Unit vector of v
(defun unitvec (v / x)
(setq x (distance '(0 0 0) v)
x (mapcar '/ v (list x x x))
)
)
A few things to think about:
You could eliminate the 'p3' variable with its calculation, by using the ELLIPSE command's Rotation option instead of specifying a perpendicular-axis endpoint. Remove lines 41 through 44, and at line 46:
(command "_.ellipse" "_non" p1 "_non" p2 "_rotation" 60)
[or some other number at the end, if you don't like the resulting proportion of that]. [But see below about p1 & p2.]
Should line 16 be:
(setq more nil)
? [As it is, it will have the same effect, but only because 'nl' itself doesn't exist and therefore returns nil. But that could be anything: (setq more MarilynMonroe).]
If you make a VLA-object out of the original Spline, you can use (vla-offset) on it with positive r and negative r, to Offset it to both sides, instead of needing to pick points for the side in Offset commands. Save each result to a variable, and you can use (vlax-curve-getStartPoint) and (...EndPoint) functions on them for the Ellipse axis endpoints, and don't need two rounds of all the vectors and slopes and (mapcar)s and p1's and p2's.
Kent Cooper, AIA
It looks like you are requesting two different things - one is a pipe end that terminates within the manhole, the other is the flow path at the bottom of the manhole. Here is my take on the latter.
@jeff.wangD95HG wrote:yes i am using civil 3d...
Any reason you don't wish to ask in the C3D forum, or better yet, the dedicated C3D Customization forum?
here is the link to the latter
https://forums.autodesk.com/t5/civil-3d-customization/bd-p/190
@leeminardi wrote:
....(command "_.ellipse" "_non" p1 "_non" p2 "_rotation" 60)
....
I'm not sure this suggestion saves much if anything. The angle woud need to be calculated instead of p3.
KC: Not really. Rotation as an option in ELLIPSE is not what you apparently think, but the rotation into the 3rd dimension of a Circle that would produce the appearance that results if that 3D rotated [virtual] Circle were flattened into the drawing plane. [Experiment with it.] The axis endpoints are still picked, so the direction between them doesn't need to be calculated. 60 makes a pretty good imitation of the example -- greater number = skinnier Ellipse.
....
"MarilynMonroe"? You're dating yourself!😊
KC: One of the historical things that happened on my birthday was her death (my 10th birthday), that is, the discovery of her body (she might have died late the day before).
....
I'm still breaking the ice with vlax functions. It's not clear to me when to pursue non-vlax based tactics and when to go with vlax functions when both strategies yield desirable results.
KC: For (vlax-curve-...) class objects, a lot of things can be done with them using those functions with less code, because those will accept regular entity names, so no VLA-object conversion is needed [and they do also accept VLA objects if there's other reason to convert them].
....
Kent Cooper, AIA
