Multiple scaled curves from one curve

Rhino Rhino for Windows
1

Hi all,

Just looking to see if there is any command where you can take a curve and scale it by entering amount scaled (up or down) for each step and number of steps (something like the Adobe Illustrator blend tool, if anyone is familiar). I know I can go to transfrom -> scale and one by one input the scale amount, but wondering if there was a more efficient way? and if so, can it be combined with the array along curve, so that I get the scaled curves also arrayed along my curve?

thanks! :slight_smile:

2

Hi @CMo, Sound like you’re after the tween command.
http://docs.mcneel.com/rhino/5/help/en-us/index.htm#commands/tweencurves.htm#kanchor2573
After creating the tween curves between your start and end curve, perhaps flow along curve will do the rest of what you need:
http://docs.mcneel.com/rhino/5/help/en-us/index.htm#commands/flow.htm#kanchor1020
Michael VS

3

Hi Michael,

Thanks for the direction. I had to first measure curve and create a straight one of same distance to tween from end to end and then I could flow along curve with the scaled curves. So now I have another question along the same lines: let’s say I want each curve to rotate ever so slightly, so that from the first to the last (there are 20 in total), they rotate around the base curve 180degrees, each one in between rotating an equal amount until the last one if flipped around the curve…any command to do that? if i go to rotate i can’t set options for multiple items at intervals.
thanks again for your help!

4

Does ArrayPolar help?

5

Hi David,

I was able to do it with tween and flow along curve…but can’t figure out a tween that will rotate (essentially this is what it would be).

6

It looks like a task for Grasshopper : do you know it?

7

Is this what you want for the curves?

DC 01.3dm (67.0 KB)

Method:

  1. Create the set of curves using TweenCurves

  2. Create set of reference lines. This lines will be used for alignment. Make reference lines associated with first and last curves, then TweenCurves to fill in the res of the reference lines.

  3. Create set of target radial lines using ArrayPolar

  4. Orient the curves to the radial lines. For each curve use Orient command. Select curve, ref pt 1 is left end of associated reference line, ref pt 2 is right end of associated reference line, target pt 1 is inner end of appropriate radial line, target pt 2 is outer end of appropriate radial line. Repeat for each curve.

Slightly tedious but the example only took about ten minutes. If lots of curves then setting this up in Grasshopper may be worthwhile.

8

unfortunately i don’t know grasshopper…have looked at a few tutorials on it and i get lost…actually got lost a little in your explanation there a little bit! :wink:

but i just went through and rotated the curves around my central curve one by one, so no big deal. now am figuring out how to extrude curves along the curve (but that specific function gives me crazy results, not what i’m looking for). so just playing around and doing it manually.

thanks for your help