Efficient Curve Tools?

Can anyone touch on the subject of bezier curves omission in Rhino? (if it’s there, I can’t seem to find it)
Coming from other application I find it so much easier and efficient to trace 2D photos using that tool
than any other tool I could find in Rhino.

It took me 3 times longer and double the amount of points (5 to 10) to get the same shape in Rhino compared to my usual 2d application.

I’m sure my technic will improve in time but it would be interesting to understand why not provide such a tool in such a complete application such as Rhino.

I’m attaching the image in question with the amount of points on the 2d App for reference.

The points you see in your image are only the segment end points the app is showing you - if they are degree 3 Bézier splines, they have two more control points between the end points that are not being shown. (a degree 3 single span Bézier spline must have degree+1 control points, i.e. 4)

You might try _HandleCurve in Rhino. It allows you to draw curve segments a little more like illustration programs.

I see your point :wink: Though it’s the lesser issue. I’ve seen videos of experienced users
working magic with this HandleCurve tool but I find it very hard to master for precision tracing.

Looking back at when I learned to use bezier curves I remember it was very intuitive.
With all the curve tools in Rhino, would it be so hard to add one more? Any reason why not?

I guess it depends on what you’re used to. I can’t stand the Illustrator-style of making curves and paths. But then I’m used to Rhino… YMMV.

Well Rhino is supposed to be CAD, which means it’s primarily oriented towards making designs for manufacturing–for cutting steel. Illustrator-style curves are NOT smooth enough to use as a basis for creating freeform geometry, even when built “properly,” which seems very difficult to do given the hours I’ve had to spend rebuilding graphics in Rhino for simple 2D cutting processes.

And I’m with Mitch, I can’t stand trying to use Illustrator myself.

That’s surprising to hear. For simple designs such as the image above, the curve produced by the
bezier tool is smoother with less point count (taking Helvetosaur comment into account) than I could produce using Rhino tools but as Helvetosaur said, YMMV, and my milage are limited in Rhino so I’ll keep practicing all tools.

I can see what you mean when it comes to complicated designs and the amount of control one
have over the curve. It would be hard to replicate and will get very old very fast using bezier curves, but for a fast starting point it seems to me the bezier curves has their place in the toolbox.

Making a smooth curve with the HandleCurve command is as easy as riding a unicycle and juggling at the same time.

I’ll take your word for it. Going to give it a good practice. Thx.

It’s not about point count, it’s about the actual “smoothness” of the segments of a freeform curve. In short, they’re not smooth enough, not for doing anything in 3D.

Hello -

Probably because when it comes to drawing high quality curves for surfacing, Rhino’s NURBS tools are much better - especially if G2 continuity is needed, which is most often the case. There would be a lot of interface work needed, all in order to make second-rate curves, and no one is standing in line here to take that on. (We tell users to look carefully at curves coming in from AI, because they may not be ideal for surfacing.)

-Pascal

A single span NURBS curve is exactly matches a Bezier curve of the same degree.

For degree 3 curves (typical Bezier) use a degree 3 NURBS curves with 4 control points.

Much appreciated! Probably saved boat load of clicking.
I do have 500 hundred similar items to bring over to Rhino before modeling it into the actual final shape.

With the bezier curve it would take me about 30 seconds to trace an average shape. Is the HandleCurve the best tool for the job or maybe something else?

For this particular one I made a polyline through 5 points, exploded the curve, changed the degree and traced each line to fit one curve. 2 Filet curves and joined. Really nice result but a bit longer than I would want to spend on one image. Tried the handle curve. could not make it work :disappointed:

This comes up all the time, so I made a little video on it, hope this helps!

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Thanks for posting. Definitely picked up a trick or two there. It really is the small stuff that gets you :roll_eyes: For that little bump I ended up doing a 3 unit fillet and worked my way from there.

I can see the blend curve coming very handy for the continuity of some curves. Thanks again!

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Best of luck with your project! As you can tell from the vid, you can really get in a groove and do one every 10-15 seconds, depending on tolerance, so hopefully those 500 assets you have to convert won’t take all summer.

Tracing those is the least of my worries. Some of those fins are so uniquely foiled I can see many
posts in my future pulling hair on how to create those smooth complicated surfaces without pushing and
pulling endless control points. That’s probably where my summer will go :grinning:

Not too much room for tolerance here, I can’t mass with years of magic for surfer dudes who rely on fins. That’s just bad karma.

Oh super cool! I actually do aerospace surfacing professionally, and I’ve been working on a whole series for my channel on best practices on drawing airfoils (hint, it’s a LOT like what I showed you already) and then how you can cleanly loft “elliptical” wings - really just any wing where either or both the leading edge or trailing edge are curved. I was chatting with @Stratosfear about this a few weeks back and we were both hashing out ways of really quickly lofting surfboard fins. You’re in for quite a challenge but feel free to hit me up. I lived in Santa Cruz for nine years, although I didn’t surf I’m aware of how finnicky those folks can be, how it can all come down to the intangible.

-Sky

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Thanks Sky! Checked out your channel, Great Stuff. Looking forward for some downtime to pickup more technics.

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I thought I could handle surf fins with grasshopper with ease. I expected Sweep 2 rails to align cvs evenly like surface loft. Instead I’m looking at point editing them or some other work around @pascal @sgreenawalt



Why? These commands do very different things. Can you post the inputs?

-Pascal