Dimensioning in 3d Model Space - How?

[Bughunter]

I'm only an occasional AutoCad user, and I haven't been able to figure this
out.

I'm importing a reasonably complex 3d model into autocad R13 using a .dxf
file. It's a computer generated
3d geodesic structure made up of many connected line segments. I'd like to
be able to apply an aligned
linear dimension to each line segment, and also show the angles between
segments.

It would be most convinent to have a little lisp script to apply the
dimensions to any selected segments.
I'm hoping that with such a script, I could rotate the model, select a group
of segments, and display the
dimensions and angles for the selected segments.

But, I can't even seem to do this manually. If I snap to intersections, I'm
able to place a dimension along
a line segment, but the length displayed is relative to UCS, and not the 3d
length as shown by DBLIST.

Is there a way to do this? I can find no reference to dimensioning in 3d in
my books.
Is there an addin available to do this? What is the correct approach to
dimensioning a complex 3d
model?

Rick

[Hightechlowtech]

Hi.
You are pointing to a problem, that can only be solved, by using an
application, that calculate the dimensions from the entities, rather from
their projections.
I have such applications, or maby it is better to say, that I use rutines,
that allow me to make dimensions for 3D objects, -------- but even you
maneage to calculate the dimensions, you still can only place them right in
one particular window, in one particular view. If you change your view, the
dimensioning lines and text, will not be in the right place. -------- the
dimensioning you place, can be hard to se, in other views, as they are 2D
entities placed in 3D.
As when you put measures on a 3D object, AutoCAD do not allow you, to make a
measure of an angle in 3D, unless you accept the projection onto the current
view plane. This mean, that an angle of a corner of a box, that you _know_
is 90 deg. , are dimensioned as being 33.583621 deg, and the only way out,
is if you make your own 3D dimensioning tools. --------- Quite easy though,
you just need a little Lisp.
Best regards
Per Corelli
http://w1.1396.telia.com/~u139600113/

Bughunter skrev i meddelelsen <8c1j3...@enews4.newsguy.com>...

[Bughunter]

That does exactally what I wanted.
The usefulness of UCS is a whole lot clearer to me now as well.

Thank you very much,
Rick

"Joe Funk" <joe...@coastnet.com> wrote in message
news:seb2d...@corp.supernews.com...
> Before issuing the dimension command, align the UCS x-axis with
> the segment. At the command line:
> :UCS
> :3
> :<pick "origin" end of segment>
> :<pick other end end of segment>
>
> or in LISP:
> (setq PT1 (getpoint "\nFirst point: ")
> PT2 (getpoint "\nFirst point: ")
> )
> (command "._UCS" "_3" PT1 PT2 "")
>
> This only accounts for the direction of the x-axis; you
> will probably have to rotate the UCS about the x-axis to
> have the dimension text appear plan to your view.
>
> "Bughunter" <foo...@aol.com> wrote in message
> news:8c1j3...@enews4.newsguy.com...