Toon Shader Shadows


I have been fiddling with Blender’s internal toon shaders. As you can see, I’ve attached a lamp to a light bulb object. The light fixture’s cage casts a shadow on the ceiling, which I kind of like. However, that shadow doesn’t soften as it gets further away from the cage. Notice the black area on the side of the chair. That’s the shadow from the cage. So here’s the question: How do I cause the strength of the shadow to decrease as it gets further away from the object casting the shadow? In real life, the edges of the shadow would get soft and the shadow itself less dark. Since this is a toon image, I’d prefer not to have soft edges, but certainly a fainter shadow, and eventually no shadow at all.