Thanks, Michael. I did notice the gap, so I straightened the surface points along the join. Even without the gap it would not shell in Moi. It did in Rhino though, so maybe the tolerances in Rhino are looser for this option, although the general tolerance I had set to .001, the same as MoI.

I guess trimming larger surfaces is the way to go. I still think in a Solidworks way. In SW to create this surface I would have created helper planes along the edges then used a patch with surface continuity to the helper planes. Is there a similar method I can use in MoI as I am still struggling a bit with MoI and complex surfaces? I created this surface with a sweep, with maintain tangent set, which probably accounts for severely curved edge, which is causing the problem.

This canopy is particularly difficult as the aircraft windshield and side widows are flat. The frame where the sliding canopy joins it is basically flat sided. On this model of the Tempest where they introduced the bubble canopy, the bubble part has to transition to basically straight edges at the front, so it closes with the windscreen frame. I guess that they made the mold with wood and just sandpapered it until it fitted!

Hi Steve,

> In SW to create this surface I would have created helper
> planes along the edges then used a patch with surface continuity
> to the helper planes. Is there a similar method I can use in
> MoI as I am still struggling a bit with MoI and complex surfaces?

Since MoI does not currently have a patch with continuity or match continuity command, that particular approach doesn't really work very well in MoI - currently in MoI it tends to be better to build one big full surface instead of a half surface that's then mirrored.

It's a lot easier to get a smooth piece if you build the full thing all at once, see here for an example:
http://moi3d.com/forum/index.php?webtag=MOI&msg=1398.18
http://moi3d.com/forum/index.php?webtag=MOI&msg=1398.19

- Michael

So for a case like this a shell/offset friendly version would be something like some sections like this:



Then build a loft or whatever through those to make a larger and more evenly shaped surface:



Then that can be trimmed by a side profile or by the fuselage body to cut away the excess:





Building a full surface instead of only a half piece will make it easier to get a fully smooth end result, and by building it as an extended and more evenly formed surface it will be a lot better quality for doing offsets since it won't have any tightly curved spots or areas that change curvature very rapidly in a small area like the "pole" zone of the previous 3-sided sweep will generate - trying to directly surface a 3 sided thing like that where one side is a lot longer than the others and swoops inwards in a 90 degree bend tends to make bad shaping in the tip area.

3DM model also attached.

- Michael

Thats great. Thanks, Michael.

If you are interested, this is how far I've got:

It's looking good Steve!

- Michael