Smoothness of spheres

Hi everyone.

I use CorelCad with my 3D printer and have noticed that certain shapes are not as smooth as I would like. What I'm talking about is, for example, a sphere appears to be made up of sections rather than a smooth ball. Is there a setting in CorelCad to adjust this resolution? I can't find it.

By the way, the model in CorelCad also shows the sphere in this way.

Thanks for the help.