Ray Tracing Update

  Specular reflection is added and the ray tracing depth is 2. 

The above image after diffuse reflection was removed. To see the other effects clear, I have adjust the image using OpenCV APIs. All the pixels is of 32 bit float format when rendering and transformed to be a RGB image with 8 bit per channel.

 Shadow rays is added. Two light sources.

 Diffuse reflection is removed.

 Soft shadow is supported. 16x16 shadow rays were emitted when rendering the soft shadow.

Diffuse reflection is removed.

I also implemented pixel multisampling. All the original images are rendering in 1080P but after I downsampled them to be half HD, the zigzag border became not obvious.