Grasshopper

generative modeling for Rhino

# Curve along curve

Hi everyone!
A quick question. I am trying to create a sine like curve that follows along a given curve. So I started by diving the curve and using those points. But in the end I am getting the points but their numbering is what I have to change. I know there is something that allows you to change the arrangement/ numbering points. Please help!

These are the points I get

But this is how I want the curve to go:

*Also, how come when I change the values for the plane normal it only affects between 0 and 1???

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### Replies to This Discussion

Hi Deepti,

what do you mean by "numbering"?

A Sine function has a period of 2*pi. If you want to speed up or slow down this frequency, you have to multiply a value to the variable PRIOR to calling the sine function. For example:

Sin(t)

gives you a wave with a period of 2*pi, whereas:

Sin(t*2)

gives you a wave with a period of only pi. Multiplying t with numbers higher than one will speed up the wave, while numbers between zero and one will slow down the wave:

Sin(t*0.1)

by reducing the t value to a tenth of its original value, the sine wave is slowed down to a period of 20*pi.

----

If you want to adjust the amplitude of the wave, you have to multiply AFTER the sine function. The default sine:

Sin(t)

will go from -1.0 to +1.0 on the vertical axis, whereas:

5 * Sin(t)

extends from -5.0 to +5.0

--
David Rutten
david@mcneel.com
Thanks for the reply David! But as you can see in the images, I didnt try to build it so far using the sine function [well because I dont know how to make it follow along a curve]. So how does the pi factor come in?
Use the weave component with the two list, that will produce the "numbering" thing that you are looking for.

Also i think that someone already do what you are doing but using the sin component or formula (like the one David explain).
OMG! Yaaay Thank you so much Manuel! :D
Hey Manuel,
I tried searching the forums but couldnt find any discussion about sin component...Do you by any chance know the link to it? Because I want to learn how it can be done...
Many Thanks
I created something that might be helpful to your inquiry. Tell me what you think.
Attachments:
Thank you!

Hello everyone.

I am a newcomer to grasshopper and I found the forum method of learning just wonderful.

Working through the primer and some personal investigations I have been playing with curves through points and variables which effect them. Lots of fumbling and person frustrations aside, I seen this post and having looked at your Definition, Josef and your theory Deepthi and David I am most intrigued.

Still getting to grips with the idea of a "Weave". I have some questions for you.

I understand that adding a multiply you can adjust the amplitude of the wave. How could I vary the amplitude across the wave with regards to "sinewavecurves" definition?

I attached an image to better illustrate my theory.

Any push in the right direction would be greatly appreciated.

Best patrick

Attachments:

It's been a while Patrick, as I've graduated and don't have access to rhino anymore. However, as I recall, there are graph buttons that allow you to project any number of formulas into a line like your picture. Once you put in the correct equation, it would then just be a matter of mapping the output to the .ghx already supplied here.