I want to sweep (loft?) from one of those two profiles to the other, following the yellow rail:



If I select the two profiles, choose "Sweep" and then select the rail, I get this:



which isn't really what I want.

Hi Andre,

maybe you could try to select the three curves and then run the Network command.

Regards
Stefan

... and when I do a sweep it works for me under beta4 (Windows).

Regards
Stefan

network 3 curves

loft 3 curves

loft 2 curves sorry ;)

Hi,
try this method.
Cheers
Barry

Hi Andre,

I don't know what you want to do, but, you have some other possibilities to do near what you want.

A revolve with rail revolve


A network



As I wrote, this simple methods don't give exact results but it depends if you want an exact sweep equivalent or a general result.

You can also sweep on your rail only the part where your curves don't have a common axe and then add a plan with edges to close the surface.

Hmm, I'll see if I can make one of those methods work.

This seems to have nothing to do with the two profiles touching each other, the same happens if I pull them apart:

Hi Andre,

re:
> If I select the two profiles, choose "Sweep" and then select the rail, I get this:
> <....>
> which isn't really what I want.

The reason you get that result is that Sweep functions by moving the profiles along the rail and also rotating them at each rail position so they are perpendicular to the rail curve.

Because your curve has a smaller radius of curvature than the length of the profiles, the profiles are going to bunch up on top of each other as they traverse the bend.

You can get an idea of what's happening if you use Transform > Array > Curve to duplicate a profile the curve, it uses a similar mechanism:



Or also here's a simpler view of the same kind of situation:



In the future I would like to make a variant of sweep that works by a pivoting method that would pivot profiles around a single rotation axis and just having it touch the rail instead of placing profiles perpendicular to the rail. But currently there is only the latter method for sweep.

There are a variety of different things you can use currently though.

If you remove one section of the profiles, the one that is the furthest away from the rail then there is barely enough room to sweep those pieces:





Then form the top and other areas by Construct > Planar rather than trying to use Sweep to form the top area:



And also use Construct > Planar to form the other sides as well:





Also some approaches using other tools instead of sweep have been described by others above.

- Michael

Hi Andre, also here is another illustration of how the profiles will be rotated as they travel along the rail curve, if this helps to explain why you are getting that bunched up result:





So if a profile sticks out too large of a distance away from the rail it's going to make the profiles criss-cross over each other:



In order to avoid bunching up the profiles need to extend no further than something like this length away from your rail curve:



- Michael

Yeah, I figured something like that. I got a better idea of how the sweep works, by moving around the profiles and editing the rail points, both of which will update the sweep in real time. This gives a good impression of what is happening. I was able to use yours and Phiro's method to get a good result now.