Ray Tracing 013Positionable Camera (FOV)

Summary

• Updated camera class with fov and aspect ratio parameters used to compute theta, half-width, half-height, and define the lower-left corner.
• Updated raytracer class to take a camera with the config-object or initialize a default camera.
• Updated with a set of new test spheres, a camera, and a few camera-preset buttons.
• Updated reset() function in engine class to reset raytracer config as well.