Rotate an ellipse along a curve

Replies to This Discussion

Permalink Reply by Joseph Oster on August 27, 2017 at 2:41pm

You didn't internalize your 'Geo' param ("Curve along which the elipse should be rotated").

Not quite sure what you mean by rotate, but maybe you want to start with a 'PFrame' at each point?

Attachments:

• Rotationalongcurve_2017Aug27a.gh, 10 KB

Permalink Reply by Pag_ on August 27, 2017 at 2:53pm

Sorry I forgot. Here it goes again.

Attachments:

• Rotation along curve.gh, 6 KB

Permalink Reply by Joseph Oster on August 27, 2017 at 3:18pm

Using your curve instead of mine - same effect, 3D view:

Attachments:

• Rotationalongcurve_2017Aug27b.gh, 9 KB

Permalink Reply by Pag_ on August 27, 2017 at 3:34pm

Thanks, but I need it to be in the xy plane. 

Permalink Reply by Ethan Gross on August 27, 2017 at 2:42pm

You didn't internalize your geometry so I created my own ellipse and curve but you should get the idea.

Attachments:

• Rotationalongcurve b.gh, 8 KB

Permalink Reply by Pag_ on August 27, 2017 at 3:01pm

Hi I just checked it and it just works when it is a ellipses that is along the curve but it doesn't work when the center of the ellipses is the end point of the curve. I send you the definition with the new addition that you kindly helped me with.

Attachments:

• Rotation along curve.gh, 7 KB

Permalink Reply by Birk Binnard on August 27, 2017 at 3:23pm

The attached file is not quite right but might be close to what you want. The idea is to create planes for the ellipses that are perpendicular to the circle. What my solution does is create points along the circle (the Divide object), find the tangent to each point (Eval), use these points & tangents as points and normals to construct planes (Pl), and then draw an ellipse on each plane (Ellipse).

The problem is that, for some reason I do not understand, the first ellipse has the wrong orientation. Since I have no idea why this happens I have no idea how to fix it.  Hopefully someone else here knows why this is happening (and how to fix it.)

An even more peculiar thing is that if the number of ellipses is even, another ellipse shows up oriented incorrectly on the opposite side of the circle.

Attachments:

• Rotationalongcurve-bb.gh, 9 KB

Permalink Reply by Pag_ on August 27, 2017 at 3:27pm

I will look at it thanks!

Permalink Reply by Joseph Oster on August 27, 2017 at 3:52pm

Or... maybe you want to create a 'RevSrf' out of each ellipse and string them along lengthwise, like beads?

Attachments:

• Rotationalongcurve_2017Aug27c.gh, 14 KB

Permalink Reply by Pag_ on August 27, 2017 at 5:44pm

I would need this in 2d. Ethan Gross definition works, but the ellipses which have center point on the endpoints of the curve are not rotating in the right direction, only the ones that have a linear section on either side. 

Permalink Reply by Ethan Gross on August 27, 2017 at 6:14pm

It looks like you tried to mate Joseph and my solution with unpleasant results, so working with that, I made some changes. I also used my own curve for demonstration purposes because yours is about 8000 meters long, while the ellipses are tiny.

Attachments:

• Rotationalongcurve c.gh, 11 KB

Permalink Reply by Pag_ on August 27, 2017 at 8:30pm

Thank you very much! It works amazingly!! Thank you all for your help!