Loft corner to smooth

Problems55.3dm (41.2 KB)

In the attached I would like to create a loft from circle to the lines with the ellipse. I would like a rapid transition from the angles to curves.

How might the be accomplished.


Like so?

Something like that (better than anything I have gotten so far)—but I would actually like to get a quicker transition to a curve.


If I’m reading you correctly you’d like to have the half square half circle shape to become completely cylindrical much faster along the length of the transition? If that is what you are looking for you can simply move the circle closer to the half square/circle, but if you want a smooth transition you can extrude the circle and square/circle away from one another and use the blend surface command. The blend surface will result in a more organic looking shape.

The two frames that I have a fixed locations. I don’t want a circle farther up but rather a more rounded curve.

What did you do to get your shape?

I have been getting something that might eventually work but using those two shapes for a closed sweep2 using a line between the two.


I drew some perpendicular lines from the square corners to the circle, then some perpendicular lines from the circle to the square/circle. I then used those lines to split the original circle and square/circle, then lofted.

In the second example after splitting the curves I ran surface blend at G4 added alignment shapes at the split points and pulled the curvature handles around a bit.


In addition to OSTexo’s methods, and because the 2 planar curve are not parallel, you could create temp surfaces for the blend - one way is to create planar surfs with the 2 curves, then offset to build perpendicular surfaces at each curve to use for the blend surface.
The blend dialog gives you the option to adjust the handles in pairs so you can accurately adjust the shape transition. Then finish up with sweep2 for the gaps.

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The second method I showed consists of the circle and square/circle extruded away from the surface to be created and the entire surface set blended. Going up to G4 gives you the opportunity to really compress the blend on the square/circle side and preserve higher continuity unlike a loft or sweep.