Rhino 6.30 (2020-10-14) cannot display SubD objects in the raytraced display mode. When I view the SubD objects in the raytraced display mode, the viewport is uniformly white, while the status bar shows progress in rendering. When I tumble the raytraced view, sometimes arctic display mode appears for a small fraction of a second.
Rhino 7 displays SubD objects in the raytraced mode as clouds of dots (shown in the following screenshot). The latest release of Rhino 7 (7.0.20301.12003, 2020-10-27) crashed when I viewed non-SubD object in the raytraced mode. Previous release of Rhino 7 crashed when I viewed SubD objects in the raytraced mode. The outline of the raytraced viewport sometimes trembles chaotically in Rhino 7.
No matter what I display in the raytraced mode of Rhino 6 or 7, Rhino temporarily freezes. It takes me at least one minute to escape from the raytraced display mode because Rhino temporarily freezes. Rhino 7 intermittently shows “Not Responding” message in its window title. (In my opinion, there should be a stop button in the raytraced display mode.)
The rendering panel has ‘reset to defaults’ button. This button does not improve the raytraced display mode in Rhino 6 or Rhino 7.
I use Quadro K2000M graphics card (NVIDIA driver 426.78, 2020-6-24). My laptop has 2GB of dedicated video RAM and 15.8GB of shared video RAM.