CSCI 480/580 Lecture 9 - In-Class Problems

A camera view ray intersects a surface at the 3D point $\mathbf{x}$. For each light source, we will generate a shadow ray and use closest_intersect to find whether there's an object blocking the light source. The closest_intersect function is called as follows:

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closest_intersect(objs, Ray(orig, dir), tmin, tmax)

The objs argument is just a list of objects in the scene - we'll assume that's taken care of.

1. For a directional light source in direction $\vec{\ell}$, give the ray orig, ray dir, tmin and tmax for the shadow ray. Note: in this class we will follow the convention that $\vec{\ell}$ points towards the directional light source and thus points opposite the direction that light is actually "traveling".
2. For a point light source at 3D position $\mathbf{s}$, give the ray orig, ray dir, tmin and tmax for the shadow ray.