How can I tie a simple knot

I want to model a simple knot like the picture I have shown.
Does anyone have any suggestions on how to model this? I am going to use more for a square shaped string, but I couldnt find any images like that.

Any ideas are appreciated, thank you.

Hello VioletRain, knots are a tricky topic, even simple ones.
When I had to do knots in the past I did a “control point” curve as path, aligned a closed curve as section for a “sweep 1 rail” on one end of the curve. Using “record history” before you do the sweep you can then fine tune your path or the section until the knot looks plausible.
Good luck!

Hi, one way to do it might be to create a straight line rebuild with enough points, then pipe with history, lock the pipe and do some heavy curve pointediting using the gumball.

…or use the curve below :wink:

SimpleKnot.3dm (161.6 KB)


Clement you are right, that would be easier, but he wants to do a square shaped string, which can not be done with the “pipe” command.

Hi Ramon, oh yeah, just seen it now after re-reading. Sweep1 should do it too using the curve i´ve posted and any shape as section. But try this to go from a pipe to a more square like shape:

  1. Use _Pipe
  2. Turn points on for the pipe surface
  3. On one side of the pipe circle, select the 4 corner points
  4. Use SelU to select all pipe circle corner points
  5. Type _Weight and use value of 10 or more



Thank you for the responses, I will be working on this next weekend so I might have some questions at that time.

Or, ChangeDegree to 1 in the V direction of the Pipe surface…


How do you turn control points on for your piped polysurface? _pointson doesnt work for polysurface
How do you change degree in just the v direction? There is a changedegree command, but it wont let me select the polysurface and when I select the curve it just wants a number.

This will only work if your pipe is created without end caps. In the _Pipe command set _Cap=_None, so the result is a surface. Then you can also use _ChangeDegree, keep the U degree as it is and enter 1 for the V degree to make it fully square.