Check if "INTERSECT" command returns another region

[ethangale25]

Hey everyone,

 

This could very well be simple, but I am not sure how to do it...

 

Here is a line in my code that uses the "INTERSECT" command on four different regions:

 

      (command "INTERSECT" currentregion massiveregion arearegion currentcourseinstanceregion "")
      (setq intersectregion (entlast))
      (setq intersectregion (vlax-ename->vla-object intersectregion)) ;convert to vlax
      (setq intersectarea (vla-get-area intersectregion))

 

In some cases, the intersect command returns the following:

 

Command: INTERSECT
Select objects: Specify opposite corner: 4 found
Select objects:
Null region created - deleted

 

when there aren't any overlapping areas of the four regions.

This in turn causes my lisp routine to fail at --> (setq intersectregion (entlast))

 

How do I "check" to see what the intersect command will return?

 

Thanks for the help

[pkenewell]

@ethangale25

1) For the first part, without the context of your full code and a sample drawing, it is kinda hard diagnose what is happening.

2) for the 2nd part: I recommend:

   a) before doing the intersect, put the last entity into a variable: (setq le (entlast)),

   b) then after the intersect, put the last entity into a 2nd variable: (setq le2 (entlast)).

   c) Then compare the handles of the two entities to see if they are the same: (= (cdr (assoc 5 (entget le))) (cdr (assoc 5 (entget le2)))).

If they are the same, then the intersect did not produce anything, if they are different, then the intersect was probably successful.

Edited March 14 by pkenewell

[mhupp]

These are poly lines or some type of shape I'm guessing? The goat has you covered like always.

https://www.lee-mac.com/intersectionfunctions.html#intersectionsinset