Trouble creating surfaces

Hello, Im trying to create this Airstream body and cannot seem to get these surfaces to join. No matter what method I try (sweep rails, Curve network, loft) I cannot close the openings on both sides. Can anyone point me in the right direction please?

RickAirstream V613.3dm (2.8 MB)

A few things:

  1. for some reason if I explode and rejoin the surfaces there are far fewer naked edges. It is almost as if the shape was scaled at some point.
  2. The top surface has some additional arc in it edges. These are G1 continuity siruation. So, an additional surface needs to be used. I split the lower edge and then blend and network surf a couple times.

Now I am not sure the G1 continuity you want on the bottom edge. But this is what you get:

Hi Scott,
Thanks for the help and suggestions. Yes, the top surface was a copy from the bottom surface that was scaled. I wanted to use the same shape in hope that it would help create a nice blended edge on the top of the airstream. Im the bottom image that you sent looks to have a kink in the surface and I’d like to avoid that. Im working on a Mac and again, no matter what surfacing approach that I take, the surfaces will not join or look uneven. Perhaps there is a better modeling approach that Im not considering? Im happy with the rest of the shape. Its only this rounded roof cap that seems to be the challenge. Again, thanks for your time.

The problem is that the existing edges are not continuous. So these edges are being used, then the resulting surfaces will not be continuous either.

See on the vertical blend at the edge, there is a hollow in the curve. A reversal of curvature? It is this hollow that is causing the odd creasing in the blend surfaces.

I would say that the end caps do not make the turn around the corner enough if the sides are supposed to be straight.

Helo - I’d back up and simplify the denser end surfaces - it seems to me you have the right idea making ‘main’ shape surfaces at the sides and top and transition surfaces to round off the corners - you could do that on the ends as well. Also you need to decide where you want curvature continuity and where you want tangency - I just made it up here to so show you simpler surfaces…

Airstream V613_Maybe.3dm (200.0 KB)


Hi Pascal,
Thanks for your help. When you say make a simpler surface, do you mean rebuild? Or what steps did you take to simplify the surfaces that you have here?


@pascal Why are the corner surfaces 4 spans in the V direction when the adjacent sides and end surfaces are 1 span in the V direction?

How did you create the surfaces? It looks like there was a lot of surface trimming. It looks like this could be done a lot simpler.

This is not the best way to do it but I deleted your top and sides. Then I did LOFT to create new sides and top (RED). Then I did EDGESRF to create the edges (PURPLE)

That joints.

Airstream V613.3dm (3.2 MB)

I presume that you want the result to have smooth edges all around which I have not accomplished. For that your curve need to be smooth (GCON command).

You could build the side and edge using one loft.

@davidcockey - well, dinner was ready… I used Refine on MatchSrf to close that up there. But I had the same question… I used the existing side panel- it’s possible it is rational - I did not check.


Sorry for the delayed response gents. Thanks very much for all of your input.

I very much appreciate the help!