Path Tracer--Got basic features right

• Anti-aliasing:

Added a random offset when each ray is generated.

   

I don't know why there are white lines on the white sphere.

• Depth of Field:

 Get the focused plane and shake the camera certain random amount in X and Y direction.

• Short Demo: 

Path tracer--Got the color right

I made mistakes in the Accumulate function for color accumulation.
Here is the corrected one rendered scene I got:

Path Tracer -- Always get flat shading

I implemented:

• calculateBSDF
• calculateFresnel
• calculateTransmissionDirection.
• stream compaction

But the rendered picture I got is always flat shading. And the color doesn't looks right.

The problem is that in remove_if function I accidentally remove all the rays that need to continue tracing. For the colors, that is because I used plus instead of multiply.

Correctted that I got this: