Topic: Question about selecting an object from a point

[Brick_top]

I'm trying to select an object from a selected point, I'm able to do it but only if the object is on screen

Here is the code

Code: [Select]

(defun c:bd ()
   (setq pt1 (getpoint "\nPonto para detectar ilha:")
         pre 0.0001
         xpt1 (car pt1)
         ypt1 (cadr pt1)
         ss1 nil
   )
   (while       
       (if
          (= (setq ss1 (ssget (list xpt1 ypt1))) nil)
              (setq xpt1 (- xpt1 pre))
         
       );if                 
   );while
)
I'm only testing in "-x" direction.

How can I select the object if it is "off screen"?

Off Topic - Also would it be better to stop creating topics? I have three already with this one

[Kerry]

Off Topic - Also would it be better to stop creating topics? I have three already with this one

I assume you mean 'three including this one'

That seems fine to me ... If they were all related to the same topic someone will probably have a little whinge though.

The topic is well named, so that will save you some grief.

[Brick_top]

I found out that I can just zoom to extents and it will select the object with no problem.

So this is not a problem anymore

It would be interesting to see if anyone has the answer though

Thanks a lot

[Brick_top]

Off Topic - Also would it be better to stop creating topics? I have three already with this one

I assume you mean 'three including this one'

That seems fine to me ... If they were all related to the same topic someone will probably have a little whinge though.

The topic is well named, so that will save you some grief.

Yeah that was what I meant!

My english could be better

Thanks for the clarification

[Lee Mac]

Another way would be to use nentselp

[DEVITG]

I'm trying to select an object from a selected point, I'm able to do it but only if the object is on screen

Here is the code

Code: [Select]

(defun c:bd ()
   (setq pt1 (getpoint "\nPonto para detectar ilha:")
         pre 0.0001
         xpt1 (car pt1)
         ypt1 (cadr pt1)
         ss1 nil
   )
   (while       
       (if
          (= (setq ss1 (ssget (list xpt1 ypt1))) nil)
              (setq xpt1 (- xpt1 pre))
         
       );if                 
   );while
)
I'm only testing in "-x" direction.

How can I select the object if it is "off screen"?

Off Topic - Also would it be better to stop creating topics? I have three already with this one

SSGET works only with object on screen , except by( ssget  ¨X¨

You can do a ZOOM center point

[cmwade77]

My suggestion is to use something like the following (unless there is more than one object at the point):

Code: [Select]

(defun c:bd ()
   (setq pt1 (getpoint "\nPonto para detectar ilha:")
         pre 0.0001
         xpt1 (car pt1)
         ypt1 (cadr pt1)
         ss1 nil
   )
   (while       
       (if
          (= (setq ss1 (nentselp "" (list cpt1 ypt1)) nil)
              (setq xpt1 (- xpt1 pre))
         
       );if                 
   );while
)
This should select items off the screen as well.

[Brick_top]

thats interesting, i have to look into that nentselp "" part, I don't know about.

but yeah there is one more object at that point, and that is a closed polyline. I have to check if pt1 is inside the selected closed polyline and if not select another one.

I found a routine that checks if a point is inside a closed polyline but, I'll have to understand how it works

thanks for all the help guys

[Brick_top]

apparently it isn't working, I typed the missing parenthesis and corrected the misspelled variable

Code: [Select]

(defun c:bd ( / ss1)
   (setq pt1 (getpoint "\nPonto para detectar ilha:")
         pre 0.01
         xpt1 (car pt1)
         ypt1 (cadr pt1)
   )
   (while       
       (if
          (= (setq ss1 (nentselp "" (list xpt1 ypt1))) nil)
              (setq xpt1 (- xpt1 pre))
         
       );if                 
   );while
)
it works if the object is onscreen

[Kerry]

apparently it isn't working,

Brick_top
Do you know what that code is doing ??

[Brick_top]

I haven't really understood the part of the nentselp.

It is changing the value of the x coordinate until it selects an object. I wrote the code, I just don't understand the tip about the nentselp.

edit - but I guess that the user that gave the tip was trying to tell me how to select the object if it is offscreen

[Kerry]

Does it select objects on screen ??

[Brick_top]

yes it does

I guess I can just do a zoomextents

[Brick_top]

I tried doing zoom extents

Code: [Select]

(defun c:bd ()
   (setq pt1 (getpoint "\nPonto para detectar ilha:")
         pre 0.01
         xpt1 (car pt1)
         ypt1 (cadr pt1)
         ss1 nil
   )
 (command "zoom" "E")
   (while       
       (if
          (= (setq ss1 (ssget (list xpt1 ypt1))) nil)
              (setq xpt1 (- xpt1 pre))           
       );if                 
   );while
 (command "zoom" "P")

)
But I guess this introduces some kind of precision error since it selects objects in other directions

[Kerry]

yes,
Selecting objects using a point off screen has always been an issue.

regarding your code ... I'll be back is a bit ..