Consider the two photographs below:

Question 1

In the image on the left, the hand casts a "hard shadow". In the image on the right, the shadow is much "fuzzier" -- a "soft shadow". What is causing the difference between these two shadows? Your answer should not only describe the characteristics of the light sources that created these shadows, but also describe how these properties result in the effects shown in the picture.

Question 2

You'll notice that in the image on the left, the shadowed region is not completely black. Why might that be?

Question 3

We've seen in class how to create hard shadows using both rasterization and recursive ray tracing. How would you model soft shadows using these two rendering techniques?