Make 2 ellipses equispace around their circumference

[Manny]

My question may have an obvious answer but I can't see it. I know that when I resize a circle within a circle the distance remains the same throughout the circumference but I can't get it to work on an elliptical shape. I've tried doing several ways but when I stretch both ellipses they don't remain equal all the wary round. Is there a way to do that?

thanks,

Manny

[Egg Bramhill]

Not 100% sure I know what you want Manny, but have you tried the Contour Tool / Inset Path?

[Manny]

[QUOTE=Manny;542761]My question may have an obvious answer but I can't see it. I know that when I resize a circle within a circle the distance remains the same throughout the circumference but I can't get it to work on an elliptical shape. I've tried doing several ways but when I stretch both ellipses they don't remain equal all the wary round. Is there a way to do that?

thanks,

Hi Egg thanks for being so quick. I was thinking of 2 oblong shapes that are centered and then entering text around the circumference just as you would with two circles. That works great but when you use oblong ellipses the same rules don't seem to apply and the distance between the two ellipses is the same all around the circumferences. I will attempt to add a file that may explain my intention better.

[Egg Bramhill]

I think I know what you want. Instead of using resize the elipse, clone it and use the Contour tool to resize the elipse & Inset Path.

[wizard509]

That's cool Egg. I didn't know about that.

[timhines]

You'll get the same problem if you resize a rectangle as opposed to a square. Because the ellipse and rectangle are longer in one direction than the other, the same percentage increase in each direction produces a different absolute amount, so the gap between the inner and outer one varies in the two directions.

You need to add a constant offset all the way around, which is why Egg's suggestion of using the contour tool works.

I hope that makes sense ... !

Edit: Another trick would be to apply a thick line around the ellipse, put a blank fill on it, then convert the line to a shape, then apply a thinner line to that shape and blank fill it, then use break shape to separate out the two (parallel) lines.

This works on all sorts of shapes. Handy for example for a simple road map - draw a a bunch of single, thickish lines representing the roads, then select them all and add them together, then convert to shapes, apply thin line and blank fill. You end up with parallel outlines with the intersections clear.

[gwpriester]

I would use circles and then resize the circles to the height and width of the ellipse. I find the Contour Tool is terrible if you are making an ellipse contour smaller.

[PhilM]

Mathematically speaking a shape with constant offset distance from an ellipse is not itself an ellipse, except when the first ellipse is a circle.

When you affinely deform a circle or an ellipse (for example when stretching one using the Selector tool) the result is always either another circle or an ellipse.

Therefore a stretched ellipse or circle cannot have a constant offset from another ellipse and only a contour, of one form or another, will do what the OP is asking for.

QED!

Phil

[Egg Bramhill]

Agree Phil, the contour tool maintains the equi-distance, were Gary's method doesn't. I agree with Gary that you can get odd effects with the contour tool but the best way around this is to create the inner elipse first and contour it out.

Diagram showing the contour tool method top, Garys method bottom.

[Acorn]

Agree Phil, the contour tool maintains the equi-distance, were Gary's method doesn't. I agree with Gary that you can get odd effects with the contour tool but the best way around this is to create the inner elipse first and contour it out.
Diagram showing the contour tool method top, Garys method bottom.

What fun!

I've just found another Xara degeneracy.
Create an ellipse and contour it - I set 5 outer steps.
With Lock aspect ratio off, reduce the height to as close to zero as you can.
What shapes can you make?
If you type in small number, like 10mp or smaller, the weirdness begins.

Acorn