CSC418/2504: Assignment 3 solution


Original Work ?


5/5 - (4 votes)

[40 marks] Your first task is to implement a basic ray-tracer and render a simple scene using ray
casting and local shading. The starter code sets up a scene comprising of an ellipsoid and a plane,
being illuminated by a point light source. Your job is to render the scene by implementing code
fragments required for object intersections and Phong shading.

You will have to implement the following code fragments:
a. [10 marks] Ray casting.
b. [10 marks] Intersection code for ray-sphere intersection (it should also work for affinely
deformed spheres).
c. [10 marks] Intersection code for ray-square intersection (it should also work for affinely
deformed squares).
d. [10 marks] Phong shading for a point light source (including ambient, diffuse, and
specular components).

To demonstrate the working of your program, you should generate three different types of
1. a scene signature where each pixel shows a unique color identifier for the first object hit
(or background). This gives you an impression of the relative positions of the camera and
the objects.

2. a rendered scene with only the diffuse and ambient components of the Phong model.

3. a rendered scene with all three terms of the Phong model.
In addition to specifying your scene, the starter code has been written to generate two distinct
views (images) every time you run it. Thus, for each type of rendering above you will generate
two views, comprising a total of six images.

In your electronic submission, please call these
image files sig1, sig2, diffuse1, diffuse2, phong1 and phong2. Below are two
images of what the Phong rendered scene should look like. Finally, ray-tracing is computeintensive, so debug your code on small images, e.g., 200×200, and debug ray intersections using
the scene signature.

Also, when writing your code, keep in mind that your second task will build
upon this work so make sure your implementation is modular and re-usable. Make sure you read
the helper code carefully and only implement the functions that are necessary, i.e. try to avoid
creating unnecessary structures or classes.

Helper Code To get started, we have created a simple demo for you. The demo sets up the scene
and basic class structures required. Note that the helper code is written in C++ and does not use
OpenGL. It will also provide you with a template Makefile for compilation and linking of your
programs. To unpack and compile the helper code on CDF, download the file a3.tgz and use
the following commands
 tar xvfz a3.tgz
 cd a3/raytracerLinux
 make
 raytracer

[50 marks] Your second task is free-form. you may build upon the raytracer or OpenGL to
produce an animation, special ray-trace effects or an interactive game. Use your imagination and
any resources you want (as long as you cite them in your report). As a guideline to the scope
of what is expected:

Animation or interactive game: create a hierarchical scene with several control variables (degrees
of freedom). You may use simple primitives like cubes, cylinders etc. like in assignment 1 and 2
or more complex polygonal geometry that you model or import into your program. The scene
should have some articulation (jointed figures). Animate the scene by any combination of
techniques to control your control variables…. key-frames, a physical simulation, motion capture
data or user interaction.

If you use key-frames interpolate between key-frames (use cubic
interpolation for smoothness). Lights and cameras in your scene should be animatable as well.
Render the scene using your ray tracer or OpenGL. Collate the image frames into a movie file.

Advanced ray-tracing: Extend your ray-tracer to enable recursive ray tracing to show secondary
reflection with specularities (so you can see one object reflected in another) and shadows. Then
implement at least 5 of the features below:

 Handling a non-trivial compound object, containing quadratic surfaces (e.g., a cone or
cylinder). Spheres, ellipses, planes and patches thereof don’t count.
 Handling arbitrary surface mesh geometry.
 Anti-aliasing
 Glossy reflections
 Depth of field
 Extended light sources, in order to to produce soft shadows
 Texture-mapping (an interesting procedural texture is also acceptable).
 Adding environment mapping to item 7.
 Motion Blur
 Refraction (e.g. glass spheres)

[10 marks] Write a clear one page REPORT describing:
 your overall submission.
 program, and other submitted file structure.
 what you have implemented and what external resources you have used.
 the role of each member on the project.
[10 BONUS marks] overall wow factor (check out past winning wooden monkey entries).

Turning in your Solution:
All your code should remain in the directory a3/raytracer. In addition to your code, you must
complete the files CHECKLIST and REPORT contained in that directory. Failure to complete
these files will result in zero marks on your assignment.
Your code should be well commented if you want to receive full (or even partial) credit for it. To
pack and submit your solution, execute the following commands from the directory containing
your code (i.e., a3/raytracer):
 cd ../../
 tar cvfz a3-solution.tgz a3
 submit -c csc418h -a A3a a3-solution.tgz (if registered for CSC418)
 submit -c csc2504h -a A3a a3-solution.tgz (if registered for CSC2504)

This assignment will be demo’ed to the TA’s during an alloted time. You are welcome to work on
any platform but must be able to run your demo in front of the TA. Also your submitted files
must either run on CDF (Linux), or provide a self-contained windows compilation environment
(Do not expect the TA’s to fiddle with the project settings or search for 3rd party libraries to
compile your code).