find pipe inverts at arbitrary location?

[cadtag]

Is there a straightforward way to get the invert of pipe at arbitrary points along the run? I've got an existing sanitary system to model, and survey data includes pipe sizes and inverts at manholes, and lateral service cleanout locations. I need to know what the invert elevation is where the laterals would tie in.

this is a renovation job, and we need to stuff some large stormwater pipes in the RoW (48" to 60" Strm in a tight residential neighborhood for retention and flood control), so I'm trying to minimize conflicts with the existing as much as possible. Especially sanitary...

[Opie]

I cannot think of a way to label the pipe elevations anywhere on the pipe. The labels I use to label the pipe end elevations are actually structure labels.

[cadtag]

yeah, seems like the simplest step will be to place null structures after the main runs are in. I don't really care about labeling them per se -- I just want to have the laterals 'properly' located in 3d space.

of course, that's pretty kludgy.

[BlackBox]

See this old thread, specifically Jeff's comments, for some useful info on a related topic.

...

HTH

[cadtag]

So, are you busy coding up a user friendly version?

[BlackBox]

So, are you busy coding up a user friendly version?

Haha... While this would make for a great plug-in, I confess, I'm not at the moment... I'm busy doing real work for my new employer (I'll add it to my list to revisit, once I settle in).

[Opie]

This isn't pretty, but it does return the invert at the closest picked point.

(defun c:getinvert (/	     _getparam	       _myspace	end0
		    end1     height   inv0     inv1	pick
		    pipe     point    space    tempLine
		   )
  (defun _getparam (pipe param)
    (vlax-safearray->list
      (vlax-variant-value
	(vlax-get-property pipe 'pointatparam param)
      )
    )
  )
  (defun _myspace (/ adoc space)
    (vl-load-com)
    (setq adoc (vla-get-activedocument (vlax-get-acad-object)))
    (setq space	(if (= 1 (vla-get-activespace adoc))
		  (vla-get-modelspace adoc)
		  (if (= (vla-get-mspace adoc) :vlax-true)
		    (vla-get-modelspace adoc)
		    (vla-get-paperspace adoc)
		  )
		)
    )
  )
  (if (and (setq pipe (entsel "\nSelect pipe: "))
	   (setq pick (getpoint "\nSpecify point: "))
	   (setq pipe (car pipe))
	   (setq pipe (vlax-ename->vla-object pipe))
      )
    (progn
      (setq end0     (_getparam pipe 0.0)
	    end1     (_getparam pipe 1.0)
	    height   (vlax-get-property pipe 'InnerHeight)
	    inv0     (mapcar '- end0 (list 0.0 0.0 (* 0.5 height)))
	    inv1     (mapcar '- end1 (list 0.0 0.0 (* 0.5 height)))
	    tempLine (vla-addline
		       (_myspace)
		       (vlax-3d-point inv0)
		       (vlax-3d-point inv1)
		     )
      )
      (vla-put-visible tempLine :vlax-false)
      (setq point (vlax-curve-getclosestpointto tempLine pick))
      (vla-delete tempLine)
      point
    )
  )
)

[cadtag]

Works! thanks.

(edit> spoke to soon..... picking both ends of a pipe segment (null structure at each end) after modifying ending invert

Command: getinvert

Select pipe:
Specify point: (2.04361e+006 528003.0 0.276447)

Command:
Command:  GETINVERT
Select pipe:
Specify point: (2.04361e+006 528003.0 6.41381)

Command:
Command:
Command: EditStructureProperties



Command:
Command: EditPipeProperties

pipe properties gives me an invert of -0.333 and 164.00

[mjung]

I realize this is an old thread but the need for getting the invert along a pipe still exists. Has anyone been able to either come up with a new solution or get the code to work? Trying to use the code above results in getting the pipe end invert for me.

[cadtag]

The C3DTools package from DotSoft has a rather neat routine to create a 2d featureline from connected pipes, With that you can ID specific specific points along the feature line for elevation info. Or set an elevation point for later use