hi michael
the belt is flat. I mean if I can turn it so that it has the position as shown in the picture.

Hi suman, how did you model the curled up belt that you are showing there with the rotation arrow around it, was it done using sweep or something like that?

Or are you using curve-to-curve flow for the result that you show there?

If you are using curve-to-curve flow and the twisting of the result is not what you want, you may want to instead construct a sort of ribbon surface using something like Sweep - to do that you would draw in a line along your path and use Construct > Sweep to generate your target surface, then draw a base plane underneath your starting shape and use surface to surface Flow for deforming the belt (that's where you select a base surface and a target surface rather than curves), and you can rotate the line before doing the sweep to control the twisting.

It could be easier to help you if you would post a 3DM model file with your current results in it, that would make it easier to understand what you're currently doing.

- Michael

Hi suman,

You can create the "belt" by doing Sweep by having a Profile at each end.
See 3DM file.

HTH, Colin

Hi suman, here's an example of the kind of thing you'll need to draw on the left here - here I've drawn a path curve starting in the Top view, and then turning on its control points and adjusting them (particularly in the z direction to adjust their height), to get a sort of looped path curve. Because of the edits to the points in the Z direction the path curve also goes up and down, it's not just a 2D flat curve.

Then in order to control the sweep you will probably want to place several line segments along the path and these line segments will be used as the profile curves for a sweep. Make the line segments all copies from a single one so they're all the same length and adjust the rotation of any one of them by selecting it and running the Transform > Rotate > Rotate Axis command. The "Rotate axis" command asks you for a line for the pivot to rotate around, make sure both "Straight snap" and "Object snap" are on so that you can make that rotation axis line snap on to the path curve tangent so you can rotate the lines around the curve tangent at their base points.

This is all some pretty advanced 3D editing techniques and so it may take you some practice to get used to building 3D curves and editing the rotation of lines along a 3D path like I've described here. Also it can help to use History - to do that do the sweep and then edit the path and/or lines after the sweep is in place, then the sweep will update.

The way I did it, is I started with just one single line at the start of the path and did the sweep, then compared the banking to your desired screenshot and added in some more key lines in areas where the default banking was not very close to the kind of banking that you wanted.

Now with this surface in place you can use "surface to surface" flow to apply deformed shapes on to it.



- Michael

Then in order to do the Flow, you need to set up a base plane off to the side, with objects to deform resting on that base plane. You'll select the objects to deform, run the Flow command, then select the base plane at the first prompt, and the curled sweep surface at the second prompt where it says to pick the target surface. The locations where you pick on each surface is significant, click in a similar spot near the end of one edge on both surfaces when you pick them. So the setup for the flow would look something like this with the base plane under your objects to deform:



Then the result is like this:




It can be helpful to use the "UnwrapCurve" plug-in to get a good length for the base plane so that it will match the actual length of the twisted surface and not do extra stretching or compression: http://moi3d.com/forum/index.php?webtag=MOI&msg=5136.1

The prep work for making the curled surface is probably the hardest part, since that involves making adjustments to both the path curve and all the profile line curves on it using 3D manipulation tools rather than only doing 2D work. But once you produce a base surface that is curled how you want it then you can use Flow and that will let you apply all kinds of flat shapes onto it so for the individual shapes you get to do those as flat 2D shapes. So this approach at least helps to condense the 3D type work to the sweep construction.

Hope this helps illustrate what you would need to do!

- Michael