Total internal reflection

This commit is contained in:
Armin Friedl 2022-07-30 18:46:04 +02:00
parent 8f7a44935a
commit 7ca342d5a4
2 changed files with 17 additions and 8 deletions

View file

@ -46,9 +46,9 @@ int main() {
hittable_list world; hittable_list world;
auto material_ground = make_shared<lambertian>(color(0.8, 0.8, 0.0)); auto material_ground = make_shared<lambertian>(color(0.8, 0.8, 0.0));
auto material_center = make_shared<dielectric>(1.5); auto material_center = make_shared<lambertian>(color(0.1, 0.2, 0.5));
auto material_left = make_shared<dielectric>(1.5); auto material_left = make_shared<dielectric>(1.5);
auto material_right = make_shared<metal>(color(0.8, 0.6, 0.2), 1.0); auto material_right = make_shared<metal>(color(0.8, 0.6, 0.2), 0.0);
world.add( world.add(
make_shared<sphere>(point3(0.0, -100.5, -1.0), 100.0, material_ground)); make_shared<sphere>(point3(0.0, -100.5, -1.0), 100.0, material_ground));

View file

@ -58,12 +58,21 @@ public:
virtual bool scatter(const ray &r_in, const hit_record &rec, virtual bool scatter(const ray &r_in, const hit_record &rec,
color &attenuation, ray &scattered) const override { color &attenuation, ray &scattered) const override {
attenuation = color(1.0, 1.0, 1.0); attenuation = color(1.0, 1.0, 1.0);
double refraction_ratio = rec.front_face ? (1.0 / ir) : ir; double refraction_ratio = rec.front_face ? (1.0/ir) : ir;
vec3 unit_direction = unit_vector(r_in.direction()); vec3 unit_direction = unit_vector(r_in.direction());
vec3 refracted = refract(unit_direction, rec.normal, refraction_ratio); double cos_theta = fmin(dot(-unit_direction, rec.normal), 1.0);
double sin_theta = sqrt(1.0 - cos_theta*cos_theta);
scattered = ray(rec.p, refracted); bool cannot_refract = refraction_ratio * sin_theta > 1.0;
vec3 direction;
if (cannot_refract)
direction = reflect(unit_direction, rec.normal);
else
direction = refract(unit_direction, rec.normal, refraction_ratio);
scattered = ray(rec.p, direction);
return true; return true;
} }