Block Extents to polyline

Oh Wizards of LISP and VBA,
Is it possible to create something that would allow a user to select a block and have AutoCAD generate a pline from the resulting perimeter. The bpoly or boundary command are close, but requires many picks and results in multiple plines.

I appreciate your feedback,
Eddie

 

Eddie,

I assume you are suggesting a shrink-wrap function which outlines a block reference
with a pline?

If so it would be daunting task codewise to take all possible object types into
account.

I think, though I'm not sure, ToolPak by Dotsoft has something along these lines.

http://www.dotsoft.com/

Joe Burke

 

everything is possible...;-)

Copy your block and explode
Analyze data, explode again if necessary
Grab your points, sort as necessary
Draw Pline
Delete Junk

as Joe noted, more complex the blocks
the tricker it gets...but a nice learning
project.

gl

 

Paul,

While I appreciate your optimism, I don't think "everything is possible", or this is
an example of a nice learning project.

If you still think so, post outline code regarding how you would do it.

Regards
Joe Burke

 

Not sure what the problem is here, but it is really very easy
to do. Have the user select the objects that you want to
shrink wrap, compute the composite bounding box, offset it
to be slighly larger, draw a closed polyline representing that
offset bounding box, then use BPOLY with an internal point
that's between the latter and the original figure, and it will
produce two loops, and you just discard the outermost one.

I made this long ago, but I"m not at liberty to share it here,
unfortunately.

 

If I understood your question.... you want to have an outline profile base on all the components from a block, is that right?

For what you mentioned about bpoly/boundary, what are you doing, and how are you getting those multiple plines????

This is not an easy out of the pocket solution, the only think I see here is to in some way convert all the possible enclosed areas into regions and then use the boolean operations to join all the regions and get the resulting enclosure region.

LE

 

Tony,

Obviously that idea didn't dawn on me. I'll give it a try.

Thanks
Joe Burke

 

I see now.... from what Tony post.... what is what the OP is looking for....

LE

 

Hey everyone,
Thanks for the responses.
To further describe what we're trying to do...
It would be like we are trying to quickly show the shape of different machines on the shop floor. The blocks to represent the machines are very extensive and detailed. I was just trying to replace those with a pline that showed the footprint shape or extents of the piece. There are some 150 machines with 35 different varieties in over 600 different shops.
Hope that helps understand.
Thanks again,
Eddie

 

If the machinery blocks are defined with this in mind, you could have an
outline on its own layer, and just turn off the other layers in drawings
where you don't want to see all the detail. (Of course, that requires that
other things in those drawings not be drawn on those layers.)

If they were Xref'd into those drawings instead of inserted as blocks,
they'd update in all drawings at once. Assuming that's not the case, and
you have existing drawings to "fix," you'd have to do whatever routine
you're imagining in every affected drawing anyway, so maybe you can do it by
updating the block definitions ( -INSERT <blockname>= ) instead of applying
the hoped-for routine. And with or without Xref's, you'd probably need to
do the turning off of layers in each drawing.

The "hoped-for routine" seems like a real challenge to me, at least if you
want to cover all possibilities for block definitions. If the block
perimeter includes any splines, the boundary approach suggested earlier
can't make a polyline, but offers to make a region instead, and needs an
answer to its proposal, which isn't part of the sequence if there aren't any
splines involved. If there's text involved, it ignores it, which probably
wouldn't be a problem in your application, but could if someone else wanted
to apply the approach to a different enough situation.

 

So it is an outline profile...

Just to make sure... can you post an image about what exactly you want....

LE