revolve an ellipse

[chad_cooksey]

is it possible?

[Anonymous]

chad_cooksey wrote:

> is it possible?

Have you tried the 3DROTATE command?

Terry

[Anonymous]

I also tried to revolve an ellipse and was not able to - I think that
this
is because it is not a closed polyline.

However, I found a
workaround.

Export your ellipse as a wmf file and then import it back
into the drawing
using Insert > Windows Metafile. You may have to rescale
the ellipse at this
stage to get it the same as before it was exported. I
don't know enough
about why or how it needs to be rescaled. Once the ellipse
has been rescaled
explode the imported wmf object to get rid of the
surrounding frame - the
ellipse is now a polyline (notice the multiple
vertices when it is selected)
and can be revolved around an axis.

I
seem to remember reading in this NG somewhere about how to convert an
ellipse
to a polyline but can't for the life of me find the post because if
there was
a quicker way than what I've just described then it would make
this problem
simpler.

Hope this helps.

Rob Fowler.

style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">

"chad_cooksey" <
href="mailto:chad_cooksey@sonymusic.com">chad_cooksey@sonymusic.com>
wrote in message
href="news:f0ecfd2.-1@WebX.maYIadrTaRb">news:f0ecfd2.-1@WebX.maYIadrTaRb...

is
it possible?

[Anonymous]

Here (2000i) the _revolve command works with ellipses

Juergen


chad_cooksey schrieb:
>
> is it possible?

[jbryant4]

It works only if you revolve it around a oint that is not within the ellispe. I think what he is asking, is can you revolve it about its own C'line, which you can't do.

[Anonymous]

jbryant4 wrote in
news:f0ecfd2.3@WebX.maYIadrTaRb:

> It works only if you revolve it around a oint that is not within the
> ellispe. I think what he is asking, is can you revolve it about its
> own C'line, which you can't do. Attachment decoded: untitled-1.html
>

Yes you can. First set the variable PELLIPSE = 1 so the ELLIPSE command
draws polylines instead of true ellipses. Draw a line through the center,
TRIM off half of the ellipse. Make a REGION or (PEDIT, Join) the line and
the ellipse arc. Then you can REVOLVE. Oh my a flying saucer! 🙂

--
Regards, Bernd
Designer
Burris Savvy Optics
http://www.burrisoptics.com/

[Anonymous]

You can trim a "true ellipse" in half, then create the region with the line
and the half ellipse. This method doesn't leave all the lines on the
revolved solid.

Tim Storey

"Bernd Hoffmann" wrote in message
news:Xns92346C229E22Ephantomdrafter@64.124.46.110...
> jbryant4 wrote in
> news:f0ecfd2.3@WebX.maYIadrTaRb:
>
> > It works only if you revolve it around a oint that is not within the
> > ellispe. I think what he is asking, is can you revolve it about its
> > own C'line, which you can't do. Attachment decoded: untitled-1.html
> >
>
> Yes you can. First set the variable PELLIPSE = 1 so the ELLIPSE command
> draws polylines instead of true ellipses. Draw a line through the center,
> TRIM off half of the ellipse. Make a REGION or (PEDIT, Join) the line and
> the ellipse arc. Then you can REVOLVE. Oh my a flying saucer! 🙂
>
> --
> Regards, Bernd
> Designer
> Burris Savvy Optics
> http://www.burrisoptics.com/

[Anonymous]

Or a football 🙂

"Bernd Hoffmann" wrote in message
news:Xns92346C229E22Ephantomdrafter@64.124.46.110...
> jbryant4 wrote in
> news:f0ecfd2.3@WebX.maYIadrTaRb:
>
> > It works only if you revolve it around a oint that is not within the
> > ellispe. I think what he is asking, is can you revolve it about its
> > own C'line, which you can't do. Attachment decoded: untitled-1.html
> >
>
> Yes you can. First set the variable PELLIPSE = 1 so the ELLIPSE command
> draws polylines instead of true ellipses. Draw a line through the center,
> TRIM off half of the ellipse. Make a REGION or (PEDIT, Join) the line and
> the ellipse arc. Then you can REVOLVE. Oh my a flying saucer! 🙂
>
> --
> Regards, Bernd
> Designer
> Burris Savvy Optics
> http://www.burrisoptics.com/

[Anonymous]

Thank you. Funny you can't join an ellipse arc, but you can region it.
That's what I like about Autocad, always something new to learn.

--
Regards, Bernd
Designer
Burris Savvy Optics
http://www.burrisoptics.com/

[jbryant4]

No, you can't. If you set PELLIPSE = 1, AutoCAD doesn't draw a true ellipse. Compare the two. Draw one with PELLIPSE = 0 and one with it set to 1. You get diiferent objects.

[jbryant4]

I tried this and it didn't work. I was ablt to create a region from the "halfed" ellipsed and the line, however, when I do a 3D Revolve (Using the top and btm of the line in the center) I don't get a solid.

[jbryant4]

Take that back...it did work. Must Render to see the Solid Ellipse. Must be some king of bug.

[Anonymous]

Increase the value of ISOLINES (e.g. 12)

Juergen


jbryant4 schrieb:
>
> Take that back...it did work. Must Render to see the Solid Ellipse.
> Must be some king of bug.

[Anonymous]

Jürgen: How come I can´t revolve a trimmed ellipse with the REVOLVE
command, but I can with the REVSURF command?

--
__________

Bill DeShawn
bdeshawn@prodigy.net
http://pages.prodigy.net/bdeshawn/bdeshawn.htm


"Jürgen Palme" wrote in message
news:3D1DEB11.E74D064@debitel.net...
> Increase the value of ISOLINES (e.g. 12)
>
> Juergen
>
>
> jbryant4 schrieb:
> >
> > Take that back...it did work. Must Render to see the Solid Ellipse.
> > Must be some king of bug.
>

[Anonymous]

The revsurf command creates surfaces, the revolve command needs a
*closed* shape and creates a (nurbs smoothed) solid. If you wand to
create an ellipsoid (solid),
- draw an ellipse,
- draw a line from one quadrand to the other quadrant,
- trim the half of the ellipse,
- create a region (from the closed shape - half of the ellipse and the
line) and now
- revolve this region.

This should work

HTH
Jürgen



Bill DeShawn schrieb:
>
> Jürgen: How come I can´t revolve a trimmed ellipse with the REVOLVE
> command, but I can with the REVSURF command?
>
> --
> __________
>
> Bill DeShawn

[Anonymous]

Aha! A region. Thanks for the reply. Did you notice that my original
question was removed?

--
__________

Bill DeShawn
bdeshawn@prodigy.net
http://pages.prodigy.net/bdeshawn/bdeshawn.htm


"Jürgen Palme" wrote in message
news:3D206CF9.E61FE487@debitel.net...
> The revsurf command creates surfaces, the revolve command needs a
> *closed* shape and creates a (nurbs smoothed) solid. If you wand to
> create an ellipsoid (solid),
> - draw an ellipse,
> - draw a line from one quadrand to the other quadrant,
> - trim the half of the ellipse,
> - create a region (from the closed shape - half of the ellipse and the
> line) and now
> - revolve this region.
>
> This should work
>
> HTH
> Jürgen
>
>
>
> Bill DeShawn schrieb:
> >
> > Jürgen: How come I can´t revolve a trimmed ellipse with the REVOLVE
> > command, but I can with the REVSURF command?
> >
> > --
> > __________
> >
> > Bill DeShawn
>