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RaytracingInOneWeekend
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Simple sphere with normals

master
Nigel Barink 2023-03-04 19:15:27 +01:00
parent b49588773f
commit f39ff66c94
1 changed files with 19 additions and 1 deletions
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20
src/program.cpp
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@ -4,9 +4,27 @@
#include <iostream>
double hit_sphere (const point3& center, double radius, const ray& r) {
vec3 oc = r.origin() - center;
auto a = dot(r.direction(), r.direction());
auto b = 2.0 * dot(oc, r.direction());
auto c = dot(oc, oc) - radius*radius;
auto discriminant = b*b - 4*a*c;
if ( discriminant < 0) {
return -1.0;
}else{
return (-b - sqrt(discriminant) ) / (2.0*a);
}
}
color ray_color(const ray& r){
auto t = hit_sphere(point3(0,0,-1), 0.5, r);
if(t > 0.0){
vec3 N = unit_vector(r.at(t) - vec3(0,0,-1));
return 0.5*color(N.x()+1, N.y()+1, N.z()+1);
}
vec3 unit_direction = unit_vector(r.direction());
auto t = 0.5*(unit_direction.y() + 1.0);
t = 0.5*(unit_direction.y() + 1.0);
return (1.0-t)*color(1.0, 1.0, 1.0) + t*color(0.5,0.7,1.0);
}