Hi FlashFire, I'm still not sure if I understand what you mean by "pinching" - do you mean this visible crease in the model here:



That's just what it looks like when you have 2 surfaces that touch each other but are not tangent where they meet.

In order to have no creases like that you need to make surfaces that are at least tangent where they touch, the best ways to do that usually are by using the Fillet command (the fillet surface that is generated by that command is created to be tangent between the pieces it meets up with), or you can leave some empty area between them and fill it in with the Blend command.

In the future in v3 I want to add some additional kinds of continuity tools to do stuff like morph an existing surface to match smoothly to another surface, currently that tools is not in MoI though. If you export your model to Rhino you can use Rhino's MatchSrf command to do that though.


> Maybe I can set Moi to build larger scale models so that edges are easier to join?

It's not a matter of joining - those pieces are within distance tolerance to be joined.

But joining 2 surfaces at a common edge and having 2 surfaces be smooth at a common edge are different things.

This is an area where NURBS modeling is quite different from poly modeling - in poly modeling when you weld 2 polygon pieces together, smooth shading will automatically flow across those polygons. That's because the shading smoothing in polys is kind of a fake thing, it's applied to polygons even though the polygons are flat pieces and not actually smooth geometry. NURBS modeling on the other hand, makes things look exactly the same as the underlying surface geometry, and to make things look smooth to one another the surface geometry has to actually be smooth, it doesn't work just by joining any pieces and having smooth shading flow across.

You can pretty easily see the difference in shapes just by eyeballing your model, like this:






So note there that the surfaces are not smooth to one another, they meet in a kind of cusp shape like this:



A cusp shape like that makes for a visible shading crease between things.


Generally with things like this you're better off actually intentionally making the crease a bit more pronounced and then using fillet to round it off. Filleting can get confused if you have some portion of a surface which is actually very close to being smooth but then it becomes creased in other areas, which is what you have here since the edges in the other direction are a lot closer to being tangent to one another.


- Michael