I’ve compiled and executed the Shadow example(https://examples.vtk.org/site/Cxx/Rendering/Shadows/).
However, Shadows were correct only when the window aspect ratio is 1.
The window size can be adjusted at Shadows.cxx:58 renderWindow->SetSize(640, 480);
.
I set the window size to 400x400 and got correct shadows.
However, to 1600x400, the shadows became elliptical and invalid black regions were created.
Both images are created from the same source code except for the window size settings (Shadows.cxx:58).
How can I avoid this problem?