Why do spots appear when rendering 3ds max vray?

Question

3D

When rendering, using a physical vray camera, it turns out like this, on absolutely smooth surfaces:

Why is it such a bad quality?
And one more thing, why graininess appears in some places and the vrayToon effect does not work correctly:

PS There are no textures, the lighting is vraysun from the window.

Answer 1

This is a feature of global illumination. It looks like you put something like a photon map there. Accordingly, the renderer traces a set of random rays of light around the scene. Due to their insufficient number, such specks are obtained, each bright speck is a ray that hit the wall, they are simply smoothed out.
Increase the number of samples/rays.

Answer 2

here, apparently, there is an irradiance map-light cache and the primary settings are understated; critical though...