Ellipse axes

[jackamus]

Is there a way to keep two objects selected whilst moving one relative to the other?

It is possible to move an ellipse to line up its major or minor axes on a line but it is not possible to align a line with an ellipse's axes.

 

If this is isn't possible then it would be useful to be able to do that. Another way would be for an ellipse's axes to be selectable  or not as desired.

[A_B_C]

Well, the first one is perfectly possible, as long as your objects are both (converted to) curves (see my video):

• Select both of your objects with the Move Tool.
• Select the Node Tool and draw a selection marquee around the nodes of the object you want to move relative to the other.
• Grab one of the selected nodes and drag your object where you want to have it.
• Select the Move Tool. Both of your objects are still selected.

And I think, the second one is possible too, provided that I understand what you meant to say. What do you mean by “aligning a line with an ellipse axis”? Is that the same as “drawing the axes of an ellipse”? If so, you will simply have to do the following (see my second video):

• Given an ellipse, select the Pen Tool and engage Snap to Geometry of Selected Curves from the context toolbar.
• Now, when you move the Pen Tool cursor along the path of the ellipse, you will see that the yellow dot indicating the snapping point will become bigger at certain points. These are the intersection points of the axes of the ellipse with the ellipse.

Hope that makes sense … 

Alex

 

First video: Relative-Move-Under-Selection.mov

Second video: Axes.mov

 

 

[firstdefence]

@jackamus I think you need to upload a few screenshots to explain better what you mean by Axes  are we talking centre points, tangental? and also what you mean by ellipse? are we talking circles or ovals or both? or are you just using the ellipse as a shape example?

 

In relation to? do you mean to rotate around another ellipses centre point and be able to move it not just around but in and out without that ellipses centre point moving, so in effect the centre point is locked to another ellipse? and you could rotate it in an elliptical orbit.

[jackamus]

Thanks ABC.

Using you first video, with the attached file, when I try to pull the whole ellipse using one of the minor axis nodes, only the node moves. I'm trying to align the line with the minor axis of the ellipse. I can do by moving the ellipse but I don't want to move the ellipse - only the line.

Video 2

As I move the cursor round the ellipse lthe major and minor nodes do not appear. Check out my attachment.

Ellipse allignment.afdesign

[A_B_C]

Okay, then you will have to do the following:

• Activate both objects, the line and the ellipse using the Move Tool.
• Select the Node Tool and make sure that Snap to Geometry of Selected Objects is engaged on the context toolbar of the Node Tool.
• Now, first snap one endpoint of your line to one minor axis node of the ellipse.
• Then, snap the other endpoint of your line to the other minor axis node of the ellipse.
• It remains to extend your line while keeping its intersection with the ellipse precisely at the minor axis nodes.
• In order to do so, activate only the line with the Move Tool.
• Select the Node Tool, hold down Shift and drag one endpoint of the line. The line will be extended, but keep its intersection points with the minor axis nodes of the ellipse.
• Repeat with the other endpoint of the line.

But the key to the method is that you engage Snap to Geometry of Selected Objects on the context toolbar of the node tool. Don’t forget to do this, for otherwise the indicated method won’t work!

 

Does it work?

Alex 

 

Line-to-Minor-Axis-of-Ellipse.mov

 

[jackamus]

Gotcha! All is well now. Thanks.

[A_B_C]

You’re welcome … 

[R C-R]

For what very little it is worth, if your shape is an ellipse made with the Ellipse Tool instead of a curve, it is even easier. Just make sure "Snap to shape key points" & snapping are enabled in the Snapping Manager (or in the popup Snapping menu on the toolbar) & moving the line end nodes with the Node Tool will snap to the end points of either of the Ellipse shape's axes. Then you can use the Shift-drag method to extend the line as above.