In Rhino 8, the isocurve is not displayed

hello. I used Rhino 7 and bought Rhino 8 last week.
After creating a cube using the ‘box tool’ in Rhino 8, the isocurve is not displayed on the cube when viewed in shading mode.
Of course, ‘Show surface isocurve’ is checked.
Isocurves are not displayed for any shape of cube, but isocurves are displayed for other shapes (cones, cylinders, etc.).
The ‘Surface isocurve display’ check for shapes other than the cube works well.

The way I did it

  1. If you create a cube in Rhino 7 and then load it into Rhino 8, the isocurve of the cube is not displayed. (In Rhino 7, the isocurve is displayed on the cube.)
  2. I deleted and reinstalled Rhino 8, but the isocurve is not displayed on the cube.

How do I display an isocurve on a cube? It’s very uncomfortable because it doesn’t have an isocurve.

type useextrusions in the command line… choose polysurface


or check this thread, if you are already using polysurfaces-

I tried, but it’s the same thing. Is there another way?

You probably need this: