This is an old exercise from the Autodesk Alias docs.
I’d already tried it back when I started making my first models with Surface Psycho, but I couldn’t get anywhere.
Today I gave it another shot and pulled it off.
Now I think I could even manage to add the fillets and make it almost a Class A model, these are all primary surfaces.
With Surface Psycho it’s all about the order you do things; first you do some stuff, then you do the rest. #CAD #nurbs #Blender3d #SurfacePsycho #b3d

The more variable I add in order to control patches, the more complicated it gets... just trying to get tangency between surfaces with a nice control cage is a nightmare, and I don’t even want to talk about G2 continuity, that’s basically hell... But at least I’ve learned to tweak every part of the surface, from a single vertex to the final result. Maybe one day I’ll pick up a new trick or two... #surfacePsycho #b3d #blender3d #CAD #nurbs

Hi, in the video you can see how to control patch shapes using the loft section curves. As you can see, by adjusting the tension you can selectively tweak the profiles, and that then changes the loft patch. This way, by modulating the tension of individual rows of the control cage, I can get patches with varying tension instead of them all being the same. It’s just an idea to show how is the surfaces control with #SurfacePsycho. Cheers. #b3d #blender3d #CAD #nurbs

This image, it seems something trivial, but in reality it is a Nubrs model, with a higher quality than those I have done in the past, this model in fact has regular Nurbs patches, with pretty nice continuity G2/G3, But I'm still learning. #b3d #Blender3d #blender #nurbs #CAD #classA #SurfacePsycho

Tips on using Surface Psycho's "Crop or Extend Patch" and SP’s Rise or "Lower Degree Bezier Patch", then I made instances with Alt+D now the copies share the same set of CVs. Making instances is really handy.
Now, as you can see in the video, splitting the big surface into three parts gives me a more even and better distribution of CVs, while I still have control over all three patches that can be tweaked with the loft curves. #b3d #surfacepsycho #CAD #Blender3D #nurbs #engineering

But with the latest version of #FreeCAD, I can no longer import the curves that are inside IGES and STEP. Is there another way to do it now? #fc3d #CAD #nurbs