F inal P roject
Raytracer with Antialiasing, Soft Shadows, Glossy Reflection and depth of field
For my final project, I have extended the Raytracer to support depth of field, Antialiasing, glossy reflection and soft shadows.

Antialiasing

This method is used to improve quality in images.   For Antialiasing I used the method describe in the book.   To be more exact I used the subpixel jittering algorithm with each subpixel being sampled randomly after subdivision. So what this does is instead of just getting the color of one pixel, the algorithm subdivides the pixel in a grid and treats each subdivision as a single pixel and at the end it gets the average color of all the subpixels. The number of subdivisions that I used for the ray tracer is 4x4 grid and the range of the random numbers is between 0 and 1.

 

                            No antialiasing                                                                       with antialiasing

               

Depth of Field

Depth of field is when a lens focuses on a subject at a distance, all subjects at that distance are sharply focused. Subjects that are not at the same distance are out of focus and theoretically are not sharp. For convenience, in my ray tracer I used the same number of jittered rays for the camera as the number of rays for antialiasing. The amount of jittering is set on the input file as part of the camera options. To get nice result the radius of the lens must be set to 0.01 – 0.5.

Without Depth of Field                                            front ball out of focus                              back balls out of focus

                              




Soft Shadows

Shadows are implemented by generating a secondary shadow ray from the intersection point to all the light sources and checking whether there are some other objects intersecting with the shadow ray or not. I have implemented Soft Shadows as it was describe in the book. This threats a point light as an area light.   To generate soft shadows, multiple shadow rays are generated towards a couple of jittered light sources around a certain light source. The returned illumination colors are averaged and assigned to the intersection point.

No Soft Shadows                                                            Soft Shadows                                  Soft Shadows and Antialiasing
                               

Glossy Reflection

Glossy refection work the same way as soft shadows but instead of jittering the ray coming from the light, the reflected ray is jitter. This is to simulate the reflection that is created from materials not are not perfect mirrors like metals.

        No Glossy Reflection                                                  Glossy Reflection

                

I Also have texture mapping and bump mapping

 

  Texture mapping and glossy reflection                      Texture mapping and bump mapping
                       

 

Another thing that I was thinking of adding to my ray tracer was path tracing and photon mapping but this didn’t work here is my attempt.

                   

             

 

And finally my final image