Target output for Program 4.

Hi folks,

Here is the output I am getting so far for prog4. I have also included ellipsoids in the output below.

Part1: Load Textures

Part2: Modulations: 1) C = Ct & A = At; 2) C = CfCt & A = At; 3) C = CfCt & A = AfAt

Part3: With Transparency

Part4: Sorting (Ellipsoid with earth texture has material alpha = 1)

https://drive.google.com/open?id=1QyoSQIJNSkfxxqk5QHBomf9UpfdXzeia

Cheers,
Ajinkya