Rhino plugin should be available to some Rhino users next week. It is powered with the same xn kernel, so it has the same capacity as XNurbes SolidWorks addin. (While the Rhino plugin is very simple, developing the plugin with Rhino SDK takes much more time than we expected: The slow progress is partly caused by Rhino SDK … So Rhino users cannot just blame us for the delay.)
Last week, we also released a new SolidWorks version, and we tested your model with it – it produces a better result for your Multiblend. (That version significantly improves the achieved tangent deviation, so does the Rhino plugin.)
If you redesign the whole tunnel using XNurbs, you can easily get G2 (see the attached screenshots and model. XNurbs replaces sweeps.). (You could get better surfaces if you would use better curves and layout.)
Multiblend.STEP (333.5 KB)
You can add more internal constraints to control the shape generated, e.g., points, curves, point cloud, curve networks… (The inner guiding points/curves don’t need to be perfect or precise, as XNurbs will automatically optimize and “correct” the guiding points/curves. So you can just draw the inner points/curves on the fly.) The above example show the use of a guiding curve. Of course, you can use any constraints, e.g., a curve network etc. The following show the use of internal points.