Ray Tracer Checkpoint 2 – Camera

For the second checkpoint we focus on the core functionality of the ray tracer; the actual ray-casting and collision detection.

I took an object-oriented design approach, keeping different components as separate as possible from one another. I ended up with the following design:

• Camera - represents the camera. Stores it's position, up, and forward vectors. Doesn't bother storing the right vector as that can be quickly determined with a cross product. Also contains the "render" method; it takes in a World object and does the ray-casting, returning a 2D array of Colour objects (the final image to be displayed).
• World - stores a list of 3D objects to be rendered. That's pretty much it. Also contains a method to transform all those objects based on a transformation matrix, but it isn't used yet.
• Object3D - represents an object to be rendered. It's an abstract class and contains one method that must be implemented by all child classes; intersect(Ray).
• Vector3 - represents a 3D vector, and implements all the standard vector math functions.
• Point3 - represents a 3D point. Essentially a vector, but without the vector math functions.
• Ray - a point (Point3) with direction (Vector3).
• Colour - stores a red, green, and blue value.

Designing it this way makes it really easy to add things in, like additional objects types (besides basic sphere and polygon) and improved camera functionality. This should be pretty awesome for future checkpoints.

Known Problems

I have a variable that sets how far away the "screen" that the rays shoot through is. Unfortunately, if I try to position the screen correctly (in between the camera position and the scene), everything that rendered is too small to see. Instead, I position it on the opposite side of the scene. I get desirable results, but it's such a hack that it makes me upset. It'll hopefully be fixed by next release.

Additionally, the actual drawing to the screen is currently done with OpenGL ( glRect ). I feel like using OpenGL for just that is a bit overkill, so I'll be looking into alternatives.

Results

Ray Casting, no extras

Ray Casting with Super Sampling

I rendered the super sampled image with a rather large offset value to show the results. In practice the value would probably be much smaller.