forum.datacad.com

How do I fill around an ellipse?
I found an answer to filling inside an ellipse. What about omitting the ellipse?
Thanks.
Steve

Try drawing a rectangle or other shape around the ellipse then hatching the area on the outside of the ellipse and inside of the rectangle.

Hi Steve,

You can do a void for many shapes, in the middle of a hatch or fill. You need to do it manually, with the 4 arcs method.



With a little practice, you can use 3-Point arcs to do the R1 and R2 arcs illustrated above.

Or, you can use the Approximate option in the Curves, Ellipse menu. You can also adjust the Arcs / Quadrant. Increase them for narrower ellipses.

Thanks for the help.
I've been using datacad since the 80's. never used ellipse/approximate. Works great for this application. Thanks, Mark!

Thanks!
I appreciate the tip.

Neil Blanchard wrote:Hi Steve,

You can do a void for many shapes, in the middle of a hatch or fill. You need to do it manually, with the 4 arcs method.



With a little practice, you can use 3-Point arcs to do the R1 and R2 arcs illustrated above.

Hmmm. As far as I can tell Border/Cont Search does not find the ellipse.
Thanks for the reply Mark.

Mark Bell wrote:Try drawing a rectangle or other shape around the ellipse then hatching the area on the outside of the ellipse and inside of the rectangle.

SCarini wrote "As far as I can tell Border/Cont Search does not find the ellipse."

Actually, you're right on this. I did a quick test using a true ellipse (dynamic) and one with Approximate used and either 36 or higher arc segments. I wasn't expecting the true ellipse to work, but was surprised the segmented one didn't allow hatching on the outside of the ellipse and outer rectangular boundary. The contour search easily filled the inside but not so when on the outside!

What was possible using contour search was to fill the inside of the ellipse, then the whole rectangle (outside), then add a void by removing the ellipse-fill from the rectangle-fill.

Mark,
thanks for the additional info.
"then add a void by removing the ellipse-fill from the rectangle-fill."
Please, what are the steps/menu selections, for adding a void?
I know I did it once or twice a decade or two ago. Can't remember how.
Thanks again.
Steve

Using the 3 images posted earlier:

1. Hatch the inside of the ellipse using contour search,
2. Hatch the outside = the full rectangle,
3. In Hatch, pick Boundary, F0 Voids, it then asks to select the master polyline = the full rectangle being the largest hatch area,
4. Then you can F8 Add Void by selecting the hatch within the ellipse - probably best to use Area - the result is the larger hatch (rectangle) removes the smaller hatch (ellipse) leaving the void in the centre,
This also works the same with Fills.

I struggled as well with not being able to hatch an ellipse.

Often I need to read the entire thread to come up with a solution.

Using approximate did the trick for me. And I went to youtube to learn how to build an arc using Neil's 4-arc method. Turned out DataCAD does the same thing when you use two arcs per quadrant, and it takes only two seconds to build my ellipse instead 5 minutes doing it longhand.

FYI when you use approximate, DC defines an ellipse as several arcs, whereas when you don't use approximate, DC defines it as an ellipse (which seems not to be recognized when hatching.)

Thanks, everybody.