topic Re: How can I create a good transition between the two surface bodies? in Fusion Design, Validate & Document Forum

How can I create a good transition between the two surface bodies?

Quefelsees — Wed, 14 Jan 2026 14:56:39 GMT

Hello all,

I want to join this wing to the fuselage smoothly. Since I cannot match the forms body exactly to the wing airfoil I somehow need to make a transition. I tried to fit it as well as I could but of course it will never match exactly.

What's a good way to join/blend them together?

Also in the process of unwelding the crease of the fuselage I created two NGons. I don't know how to fix that if that needs fixing at all. Shelling the fuselage fails as "sharp shell" and takes quite long with the "rounded shell" option though.

Re: How can I create a good transition between the two surface bodies?

TrippyLighting — Wed, 14 Jan 2026 15:12:04 GMT

See the video.
I would carefully modify the T-Spline to get a better transition. I would also keep the loft limited to tangency, not curvature continuity.

(view in My Videos)

Re: How can I create a good transition between the two surface bodies?

Quefelsees — Wed, 14 Jan 2026 17:41:19 GMT

Well, that's embarrassing... I guess this goes under the category of "there are no dumb questions" haha. Thank you!

I modified the form a little after doing exactly what you did. However back then the loft would intersect itself and wasn't able to be computed. I guess I somehow fixed it and didn't realize.

Is there btw any way of aligning the t splines, looking from the front/back (y-z-plane) into the same x-z-plane? So that the x-z-face of the fuselage would be flat?

Re: How can I create a good transition between the two surface bodies?

TrippyLighting — Wed, 14 Jan 2026 19:40:21 GMT

@Quefelsees wrote:

Is there btw any way of aligning the t splines, looking from the front/back (y-z-plane) into the same x-z-plane? So that the x-z-face of the fuselage would be flat?

Yep. There is a Flatten function in Modify->Flatten in the T-Spline menu. Yu can flatten toward a parallel plane, or exactly onto a plane.

Or you can scale to zero in one direction, depending on where your cursor is positioned that might be easier. That's an "old" Sub-D modeling trick that works in Maya, Blender etc.

Nice progress BTW!

Re: How can I create a good transition between the two surface bodies?

Quefelsees — Wed, 14 Jan 2026 22:33:09 GMT

Got it! That's a neat trick. Thanks for sharing.

Thank you, I appreciate it! Means a lot!

Re: How can I create a good transition between the two surface bodies?

Quefelsees — Thu, 15 Jan 2026 16:15:41 GMT

Aaaaannnnnd I broke it...

I just did some minor changes to the fuselage forms body and now the loft isn't working anymore with G1 tangency. G0 works but that does not look good of course. It's always intersecting itself in a weird way (see image) and I can't figure out why. @TrippyLighting can you maybe take another look? I'd appreciate it so much!

Re: How can I create a good transition between the two surface bodies?

TrippyLighting — Thu, 15 Jan 2026 18:16:36 GMT

The loft needs more "breathing room" so I trimmed away more of the wing. I also extruded a bit more of the T-Splines toward the wing and removed the crease on one edge so the profile is round. I split the wing surface into two halves and lofted each separately. I would not touch this anymore as edits will get trickier as the model progresses.
The Wing/Fuselage transition is very tricky to model!

Re: How can I create a good transition between the two surface bodies?

Quefelsees — Thu, 15 Jan 2026 22:10:14 GMT

Thank you so much! It really is very tricky. Thanks to you I can now finally go on with the rest of the project (I hope)!