How to move a camera using in a ray-tracer?

Question

I am currently working on ray-tracing techniques and I think I\'ve made a pretty good job; but, I haven\'t covered camera yet.

Until now, I used a plane fragment for vi

Answer 1

For rasterising renderers, you tend to need a transformation matrix because that's how you map directly from 3D coordinates to screen 2D coordinates.

For ray tracing, it's not necessary because you're typically starting from a known pixel coordinate in 2D space.

Given the eye position, a point in 3-space that's in the center of the screen, and vectors for "up" and "right", it's quite easy to calculate the 3D "ray" that goes from the eye position and through the specified pixel.

I've previously posted some sample code from my own ray tracer at https://stackoverflow.com/a/12892966/6782