Lisp Problem - BASE / INSBASE

AutoCAD14 (I know, but I like 14

I have a Lisp routine for quickly modifying 2D blocks that has always worked
perfectly.... until today, when I was modifying a third party drawing.

As part of my Lisp routine, a marker line is drawn that originates from the
defined insert point of the block being modified. The line is there to
indicate the insert point that was specified when the block was previously
created.

When I ran the routine on a block in the third party drawing, the marker
line was drawn displaced from the defined block insert point.

I think I have identified the problem as 'INSBASE' (or 'BASE') not being set
to (0.0 0.0 0.0). In this case it was set to (7.0 8.5 0.0) and that is
the displacement that had been applied to the originating end of the marker
line.

How do I resolve this problem?

I tried resetting 'INSBASE' to (0.0 0.0 0.0) and then running my Lisp
routine, but it made no difference (which surprised me) and the marker line
was still displaced as before.

With 'INSBASE' still set to (0.0 0.0 0.0) I then exploded and redefined
the block. I then inserted the (redefined) block and ran my Lisp routine on
it. The marker line was still displaced as if 'INSBASE' was still set to
(7.0 8.5 0.0).

I noticed that the entity code for the block (assoc 10) still gave the
insert point WITH the 'INSBASE' = (7.0 8.5 0.0) displacement applied, even
though I had reset 'INSBASE' to (0.0 0.0 0.0).

Maybe I don't fully understand 'INSBASE'. Is the 'INSBASE' setting also
stored somewhere else? How can the redefined block entity code (assoc 10)
still include this displacement, despite the fact that I've reset it to (0.0
0.0 0.0)? Am I missing something obvious?

Do I have to somehow apply the 'INSBASE' setting to the entity code (assoc
10) insert point to remove the displacement and ensure the marker line
originates correctly from the defined insert point of the block?

 

Did you purge the drawing prior to redefining the block?

 

Then you proberly need to rewrite that by allowing it first to chack
that var. and then offsetting everything you use the Lisp rutine for.
Checking the insert base shuld be easy and if it is wrong it seem
obvious too allow the offset . I would use an easy Mapcar '+ or - for
each member of the two lists , It shuld be easy to add a check for if
plus or minus are to be used .

 

I guess you're right, I have to check the variable "INSBASE" and if it's not
(0.0 0.0 0.0), use its setting to correct the displacement.

What I can't get my head round is why the displacement still occurs after I
have set "INSBASE" to (0.0 0.0 0.0) and redefined the block. Where else
is the displacement stored?

 

No! What would that have achieved?

I set "INSBASE" to (0.0 0.0 0.0) and then redefined the block using the
original block name, so all instances of the block should have updated.
There were no nested blocks to consider.

 

I don't know if it would achieve anything. It's just that, in my
experience, it's better to purger the drawing prior to recreating
blocks - especially where attributes are involved.

 

I don't know if it would achieve anything. It's just that, in my
experience, it's better to purge the drawing prior to recreating
blocks - especially where attributes are involved.

 

I now think this a UCS problem and I need to be looking at the TARGET or
UCSORG settings.

Any guidance anyone?

 

Try (setvar "insbase" (getpoint)) and just show where you want the base
point to be. That would be tedious if you have a lot of them, so you
could write a little macro for it. Oh, and you would probably want to
set it back to 0.0 0.0 0.0 when you are done. Had that problem once - I
think that's how I got around it.
Mal