Classes
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vector.h -- vector of three scalars, also used for colour
matrix.h -- matrix class, currently not used
quaternion.h -- quaternion class for camera rotation

container.h  -- container for shapes, base class for octree and kd-tree
octree.h -- Octree space subdivision structure for acceleration of ray-shape intersection search
kdtree.h  -- KdTree space subdivision structure

scene.h -- scene objects: Ray, Light, Camera and shapes
raytracer.h -- ray tracer class
common.h -- Float definition (float/double) and some helper functions


Container Usage
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(Container|Octree|KdTree) top;
scene.setTop(top)  // top object in hierarchy
top.optimize()     // build optimization structure

Rework camera
-------------
Sampler - generate points in screen plane
Camera - transform point from sampler to a ray