Program 4 - Transforms and Anti-aliasing

This assignment is due on Wednesday 5/23.

Overview:

Goals for assignment 4:

For this portion of your ray tracer, your program needs to:

• handle geometric transforms on all geometric types
• handle multiple lights
• implement the Fresnel effect by using the Schlick approximation to weight reflection and refraction
• use Beer’s law for colored translucent volumes (i.e. spheres)
• use anti-aliasing (stratified super samples per pixel)

In addition to your source code and build files, your repo should also contain:

• Your own .pov file and rendered image of a reflective and refractive scene. Be creative and create an interesting scene. Choose colors and an arrangement of geometry that you find pleasing.

Program execution:

Your program should have the following syntax:

raytrace render <input_filename> <width> <height> [-fresnel] [-ss=N] [-altbrdf]

assuming that your executable is named raytrace where the options are:

• input_filename = the name of the povray file to read and render
• width = the image width
• height = the image height
• -fresnel = use Schlick’s Approximation to simulate Fresnel reflection (optional argument) (new)
• -beers = use Beer’s law for colored translucent volumes (optional argument) (new)
• -ss=N = use super sampling with NxN samples (optional argument) (new)
• -altbrdf = use a brdf other than Blinn-Phong (optional argument)

and the command render indicates that we simply want to draw the entire scene.

Thus:

raytrace render example.pov 640 480

will render a 640x480 image file, output.png consisting of the scene defined in example.pov.

raytrace render example.pov 640 480 -ss=3

will render a 640x480 image file, output.png consisting of the scene defined in example.pov using 3x3 super-sampling.

Sample input files and images are given in the input files repository.

Diagnostic/Testing

In addition to the normal execution syntax, your program should support the following diagnostic/testing syntaxes with the given commandline arguments. You must also continue to support all Diagnostic/Testing syntaxes from the previous iteration(s) of the project.

raytrace printrays <input_filename> <width> <height> <x> <y> [-altbrdf]

Prints out information for each iteration of a recursive raytrace.

Pixel: [399, 280] Color: (125, 13, 125)
----
  Iteration type: Primary
             Ray: {0.0000 0.0000 12.0000} -> {0.1628 0.0830 -0.9832}
 Transformed Ray: {-1.0876 -0.2536 12.0000} -> {0.1125 0.0720 -0.9832}
      Hit Object: (ID #2 - Sphere)
    Intersection: {1.6662 0.8488 1.9397} at T = 10.2326
          Normal: {0.0818 0.0982 0.9918}
         Ambient: {0.2000, 0.0200, 0.2000}
         Diffuse: {0.2919, 0.0292, 0.2919}
        Specular: {0.0000, 0.0000, 0.0000}


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Grading breakdown:

• 50 handle geometric transforms
• 15 anti-aliasing
• 10 multiple lights
• 15 working schlick’s approximation
• 10 points working beer’s law