Loft question + ideas

 From:  Michael Gibson
784.4 In reply to 784.3 
Hi Xavier, just be careful leaving that angle setting down so low, that will make really really dense meshes. Any model with very many surfaces in it will display pretty slow with that density.

re: shelling - in this case the surface offsetter does not like to have that kind of 90 degree internal pivot that you've got there since the last station is rotated 90 degrees from the previous one.

That creates a kind of twisting inside the surface and it creates some difficult calculations especially right near the pivot point.

One thing you can do is to get some additional guide curves along the sides to form the final upward curve, like this:

That's just 3 sections with the guide rails continuing up to meet in a point. You can then use sweep with 2 rails, or actually in this case Network seems to be better, to make this surface:

Here you can see with the control points turned on that the surface has a more gradual shift towards the end, not such an abrupt shift inside of it like the lofted one.

This new structure has the tip collapse down to a point. This is generally a more preferred way to have things set up rather than internal twists in a surface, but unfortunately there are also some bugs in this area of offsetting things that collapse down to a point.

This surface will shell, but unfortunately due to a bug the area right around the very tip is malformed. I'd like to get this bug fixed up but it is a bug in the geometry library that I'm using, it will probably take a little while before I'll be able to send it off to be fixed.

To finish this one you may need to either make the side curves not collapse down to an actual point and fix up that area with another piece added to it, or offset the stations and try to make the shell piece by doing a second Network surface...

- Michael