Hi, I’m hoping for some help in understanding how to approach simple surfaces in Rhino and getting high quality results. I often find that the surfaces I create don’t match the continuity of the input curves. Often this is visual; All of my inputs will be tangent/curvature, Rhino will say that my surface is also Curvature or Tangent, yet the result is subpar from a visual perspective and using Rhino’s environment maps.
For example, below I have created 4 simple curves and used the Sweep 1 rail command. My rail is Curvature continuous and my cross section curve is degree 2.
This results in a surface that has tension or a “seam” where there is none on the input curves. This can be seen when using the Emap diagnostic tools. (red circled area).
These seams exist where my input curves meet each other. Rhino says that my input curves are continuous. On the zebra stripes below, you can see the areas of tension.
Here’s what the control points for the surface look like:
Here’s what the surface looks like in keyshot. These seams/breaks are very visible.
What can I do to avoid these sorts of problems? It is very frustrating that I can’t get consistently visually good surfaces with very simple inputs. What am I doing wrong? Will a surface of this sort of geometry (two single curve straight sections blended with a double curve section) always result in a surface that looks like this, and I’m overthinking it?