s_discriminant Struct Reference

This struct stores the necessary data to evaluate a ray-sphere intersection. To do that, it relies in geometry, trigonometry and the Pythagorean theorem. It's important to mention that discriminant means the number that says whether the ray intersects the sphere at all. For a detailed description, refer to: https://www.scratchapixel.com/ lessons/3d-basic-rendering/minimal-ray-tracer-rendering-simple-shapes/ ray-sphere-intersection.html. More...

#include <shapes.h>

Data Fields
double	a
double	b
double	c
double	t1
double	t2
double	discriminant

Detailed Description

This struct stores the necessary data to evaluate a ray-sphere intersection. To do that, it relies in geometry, trigonometry and the Pythagorean theorem. It's important to mention that discriminant means the number that says whether the ray intersects the sphere at all. For a detailed description, refer to: https://www.scratchapixel.com/ lessons/3d-basic-rendering/minimal-ray-tracer-rendering-simple-shapes/ ray-sphere-intersection.html.

Parameters

a	Stores a value from quadratic equation. This value is useful to identify if a ray is parallel or not to y axis of a given cylinder.
b	Stores b value from quadratic equation derived from geometry rules.
c	Stores c value from quadratic equation derived from geometry rules.
t1	Stores the distance from ray's origin up to the intersection of a given ray with shape's surface. If there is only one, it means the ray intersects the shape in only one point.
t2	Stores the distance from ray's origin up to the intersection of a given ray with shape's surface. The combination of positive and negative numbers of t1 and t2 will determine where the ray is intersecting the shape.
discriminant	Stores the information about how the ray intersects a given shape. If discriminant isless than 0, then the ray doesn't intersect the shape. If discriminant is 0, the ray intersects the shape in one place only. If the discriminant is higher than 0, the ray intersects the shape in two places.