Full Version: ARC end points tangency

Hi All, I have a curve made of a series of arcs that I need to make sure the end point to end point of each arc to the next are tangent to each other is there a way to check this moi.

Attachments:
tangents.3dm

Image Attachments:
curves tangents.png 

---

Super down and dirty way could be to extrude a surface and turn off edges and just look real quick, then back up

Maybe the CCC command can show?

I usually just rebuild, but i dont know if you have requirements to “not change anything”

The old manual method would be to turn on points and take a look at end point and point before on each curve and see if they are inline

---

Hi Alex, sorry no there currently isn't a way to check that inside MoI.

I would recommend to load it into Rhino and use the gcon command in Rhino to do it now.

- Michael

---

Hi Alex.
Look at this method.
https://disk.yandex.ru/i/OwP4FXHBH4V7Qw

---

Fillet command can show you if there is any G0 continuity (corner) in your curves.
"join" your curves >>> Run the "fillet" command (do not confirm) >>> check and fix the corners >>> "separate"

---

Many thanks WN and MO both very good methods simple approach will have a play with it and get back further results.

All the best
Alex.

---

Work flow within MOI produces a perfect redrawn curve made from arcs and tangency between each set. Manually traced over guide curve very little deviation amazing result and very quick workflow.
Many thanks to WN and MO for knowledge bank and workflow its a winner.

Here is end result from 4axis CNC tube bender compliant curve - part bent without any problems.

MOI wins again in the workflow simplicity arena.

All the best for the festive and new year and the biggest thanks to all on this forum for the continued support and open knowledge sharing.

Image Attachments:
PART BENDS.jpg 

---

Some really cool work, Alex!

- Michael

---

Special Thanks to you Michael for creating this software which is a joy to use.
Have been working on this project will post more details as they progress international high profile sculpture location withheld at the moment. The pose outer shell was done in Blender but all the presentation based hard surface modelling and PDFs 100% done in MOI. Final renders a mix of blender and rhino. Was going to produce all the fabrication files through Solidworks but with new workflow can keep the DNA of this project entirely from MOI.
All the best for 2024 and keep doing what your doing so well.
Alex.

Image Attachments:
DUSK POSE.jpg  moi model.png  PDFS.png  SITE2.png 

---

Fabulous!
with the free Vizcom https://app.vizcom.ai
maybe transparency is not exactly the same! :)

---

Wow, that's really cool, can't wait to see more construction!

Thanks, - Michael

---

Alex, very impressive work, well done and congratulations on the progress thus far! I had no idea there was such a thing as a 4-axis CNC tube bender...I'm just happy working with manual benders and blacksmithing techniques. Someday it would be really neat to see a video of the construction and installation of this sculpture, but I can only imagine that you've got your hands full with the work itself.

--Larry

---

Very cool, Alex!

---

Thanks all for input and comments and Pilou the Vizcom image regen is pretty impressive from the black and white render AI certainly moving along. The above workflow works well for a reconstructing a 2d spline into a series of tangency arcs trying to do the same workflow for a 3d curve - does anyone know if its possible for the cont/arc tool to follow a 3d guide curve as in this image I can get it follow only in 1 viewport. any advice once again welcome.

Attachments:
3d curve.3dm

Image Attachments:
3d curve.jpg 

---

Hi Alex,

re:
> does anyone know if its possible for the cont/arc tool to follow a 3d guide curve as in this image
> I can get it follow only in 1 viewport. any advice once again welcome.

In MoI when you pick points in one of the ortho (Top/Front/Right) views, the points will generally be projected onto the view's grid plane going through the previous picked point.

This is so that when you are drawing in a 2D view you can know that points you get are on that plane.

This restriction is not applied when you pick points in the 3D view, that's why you're seeing a difference when using that view. So if you want to have several points in a draw tool follow a 3D path then pick them in the 3D view.

- Michael

---

Hi Alex,

I just tried doing it with Arc > Cont. That works, but you'll need to make small steps and work in the 3D viewport only. While picking the 2nd point of each arc move the 3D view around to get an overall sense of how closely it's following the freeform curve. From some angles it might look like a perfect fit, but from other viewpoints you'll see that there's actually a big gap.

Doing this with the built-in Rotate view control will be very painful because you need to rotate the view back and forth while picking the 2nd point of each arc. I'm using a SpaceMouse and that works pretty well for this.

One thing I noticed is that the resulting polyarc tends to kind of oscillate around the freeform curve. If you need it to look really smooth you might have to change the freeform curve so that it is more like a few long arcs and straight lines. Or you'll need to make really small steps which the people doing the bending probably won't like. Or you might need to find a fabricator with a CNC bender designed for doing freeform curves rather than just radii and angles.

- Peer

---

Thanks again for advice all working nicely

---