Description

In this project, you will implement a basic ray tracer.

Code

Skeleton code is available here. This code contains a number of files, including.

The methods that you need to implement are marked with 'TODO' in the code. These can be found in boolean.cpp, camera.cpp, phong_shader.cpp, plane.cpp, reflective_shader.cpp, render_world.cpp, and sphere.cpp. A code skeleton and driver framework is provided. You will need to implement object intersections, shading, and ray casting.

To run the tests, run ./ray_tracer <test-file>, where test-file is one of the provided test files. The tests can also be run with ./ray_tracer -p <test-file>, in which case the result is saved to output.png rather than rendered to the screen using OpenGL. The tests are designed to be implemented and debugged in order and are intended to help you debug your implementation. They will also be used for grading.

The code contains many comments explaining what needs to be done and what functions should do. Be sure to read through the code and comments before you begin implementing things.

Submission Instructions

You will submit your code as one file in one of these formats: tar, tar.gz, tar.bz2, or zip. Your submission should contain:

Extra Credit

Here are some ideas for extra credit:

You may also suggest another option by contacting the professor (by email or in office hours). In any case, you will need to explain briefly what you have done and how you did it (extra-notes.txt). The presence of extra-notes.txt indicates that extra credit has been done. For each file you add, briefly explain its purpose. For each file you modified, briefly explain why it was modified. Indicate which test cases are included, how to run them, and what we should see. No credit will be given for extra credit that is not demonstrated with at least two test cases, one of which should be nontrivial and challenging. Extra credit up to 10% of the total value of the project is possible. Changes made for extra credit should not alter the behavior of the original test cases.

Grading script

As with the first project, we are providing you with the grading script that we will be using to grade this project. You can run it like this: "./grading-script.sh .". The script works in the same way in the first project, although there are no timing tests with this project. There is a 10 second time limit on each test; this should be more than enough time for the tests provided. Be sure to test your project on one of the delta machines.

Note that extra credit projects will vary from student to student and are not graded using the script (except for the Booleans). These will be graded individually.

Checkpoints

This project has one checkpoint. Checkpoints are intended to encourage you to start your project early. At each checkpoint, you will submit your project just as you would when it is due. At the first checkpoint, your program will be graded out of 12 points. No extra credit is possible at checkpoints. When your project is due, it will be graded out of 38 points, and extra credit will be given for scores higher than that.

Test cases

The table below documents the tests. Along with a thumbnail showing what the result should look like, I make some potentially helpful notes about the test case. Click the thumbnail for a full-size image.

Thumbnail Notes
files/thumb-00.png 00.txt

5 points

pixel trace

Bare minimum to getting started: flat shading, sphere intersections, casting rays.
files/thumb-01.png 01.txt

5 points

Get the coordinate system oriented correctly, introduce colors.
files/thumb-02.png 02.txt

1 points

Test image size and camera settings.
files/thumb-03.png 03.txt

1 points

pixel trace

Test irregular camera orientation.
files/thumb-04.png 04.txt

1 points

Get basic plane intersections working.
files/thumb-05.png 05.txt

1 points

pixel trace

Add Phong shading (diffuse only) and handle point lights.
files/thumb-06.png 06.txt

1 points

pixel trace

Phong shading with sphere - diffuse only.
files/thumb-07.png 07.txt

1 points

Phong shading colored material and colored light. Diffuse only.
files/thumb-08.png 08.txt

1 points

pixel trace

Add specular.
files/thumb-09.png 09.txt

1 points

pixel trace

Both diffuse and specular.
files/thumb-10.png 10.txt

1 points

pixel trace

Move light off center; break symmetry.
files/thumb-11.png 11.txt

1 points

Colors with lights, diffuse, and specular.
files/thumb-12.png 12.txt

1 points

Phong shading with full scene.
files/thumb-13.png 13.txt

1 points

Add color to the lights; make sure things work with two lights.
files/thumb-14.png 14.txt

1 points

Add background shader, introduce ambient light.
files/thumb-15.png 15.txt

1 points

Shading test.
files/thumb-16.png 16.txt

1 points

Specular shading test - test exponent.
files/thumb-17.png 17.txt

1 points

Specular shading test - test exponent.
files/thumb-18.png 18.txt

1 points

Specular shading test - test exponent.
files/thumb-19.png 19.txt

1 points

Specular shading test - test exponent.
files/thumb-20.png 20.txt

5 points

pixel trace

Introduce basic shadows. This is also a bug test; there is a very bright light hidden under the ground.
files/thumb-21.png 21.txt

1 points

Bug test: objects behind the light.
files/thumb-22.png 22.txt

1 points

Bug test: object covering up the light. Since no light escapes, the image should only contain ambient light.
files/thumb-23.png 23.txt

1 points

pixel trace

Test recursion depth.
files/thumb-24.png 24.txt

1 points

Test recursion depth.
files/thumb-25.png 25.txt

1 points

Test recursion depth.

Below are the extra credit Boolean tests.

Thumbnail Notes
files/thumb-26.png 26.txt

1 points

pixel trace

Start implementing Booleans: basic union.
files/thumb-27.png 27.txt

1 points

Start implementing Booleans: basic intersection.
files/thumb-28.png 28.txt

1 points

pixel trace

Start implementing Booleans: basic difference. Check to make sure that complex objects can cast shadows on themselves.
files/thumb-29.png 29.txt

1 points

Handle nesting of Booleans.
files/thumb-30.png 30.txt

1 points

pixel trace

Bug test: check complex interaction of Booleans.
files/thumb-31.png 31.txt

1 points

pixel trace

Bug test: check complex interaction of Booleans.
files/thumb-32.png 32.txt

1 points

pixel trace

Bug test: check complex interaction of Booleans.
files/thumb-33.png 33.txt

1 points

pixel trace

Bug test: check complex interaction of Booleans.
files/thumb-34.png 34.txt

1 points

pixel trace

Bug test: check complex interaction of Booleans.
files/thumb-35.png 35.txt

1 points

Construct a bounded object from unbounded primitives.
files/thumb-36.png 36.txt

1 points

pixel trace

Complex Booleans and self-shadowing.
files/thumb-37.png 37.txt

1 points

pixel trace

Bug test: what happens if we construct a hollow piece of geometry and fill it with a camera, lights, and objects?