Tutorials: Fine tune the rendering of a pill bottle

This tutorial is a follow-up to the Inverse Falloff Law lighting tutorial. It shows how to make a few adjustments to the pill container scene in order to fine-tune and improve the rendering. This includes using the inverse square falloff law to adjust the darkness of the background, adjusting the diffuse channel of several materials, and also applying a reflective shader to a localized region of the ground object.