On the other hand, the modern artist, even if he works by values rather than by chiaroscuro, must often wish to paint a scene that does involve shadows. We know that the scene may be filled with light and yet there will be certain places where the light is intercepted, so that shadows are formed. Our lawn in summer is aglow with warm light, but every tree and bush casts its shadow. Or the same spot in winter is covered with snow and the air is bright with cool light; yet here and there a trunk of a tree spreads a thin layer of shadow.