diff --git a/rtiww/src/main.cpp b/rtiww/src/main.cpp index 4c3cd4b..10a54f0 100644 --- a/rtiww/src/main.cpp +++ b/rtiww/src/main.cpp @@ -12,71 +12,72 @@ #include color ray_color(const ray &r, const hittable &world, int depth) { - hit_record rec; + hit_record rec; - // If we've exceeded the ray bounce limit, no more light is gathered. - if (depth <= 0) - return color(0,0,0); + // If we've exceeded the ray bounce limit, no more light is gathered. + if (depth <= 0) + return color(0, 0, 0); - if (world.hit(r, 0.000001, infinity, rec)) { - ray scattered; - color attenuation; - if (rec.mat_ptr->scatter(r, rec, attenuation, scattered)) - return attenuation * ray_color(scattered, world, depth-1); - return color(0,0,0); - } + if (world.hit(r, 0.000001, infinity, rec)) { + ray scattered; + color attenuation; + if (rec.mat_ptr->scatter(r, rec, attenuation, scattered)) + return attenuation * ray_color(scattered, world, depth - 1); + return color(0, 0, 0); + } - vec3 unit_direction = unit_vector(r.direction()); - auto 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); + vec3 unit_direction = unit_vector(r.direction()); + auto 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); } int main() { - // Image + // Image - const auto aspect_ratio = 16.0 / 9.0; - const int image_width = 400; - const int image_height = static_cast(image_width / aspect_ratio); - const int samples_per_pixel = 100; - const int max_depth = 50; + const auto aspect_ratio = 16.0 / 9.0; + const int image_width = 400; + const int image_height = static_cast(image_width / aspect_ratio); + const int samples_per_pixel = 100; + const int max_depth = 50; - // World + // World - hittable_list world; + hittable_list world; - auto material_ground = make_shared(color(0.8, 0.8, 0.0)); - auto material_center = make_shared(color(0.7, 0.3, 0.3)); - auto material_left = make_shared(color(0.8, 0.8, 0.8), 0.3); - auto material_right = make_shared(color(0.8, 0.6, 0.2), 1.0); + auto material_ground = make_shared(color(0.8, 0.8, 0.0)); + auto material_center = make_shared(1.5); + auto material_left = make_shared(1.5); + auto material_right = make_shared(color(0.8, 0.6, 0.2), 1.0); - world.add(make_shared(point3( 0.0, -100.5, -1.0), 100.0, material_ground)); - world.add(make_shared(point3( 0.0, 0.0, -1.0), 0.5, material_center)); - world.add(make_shared(point3(-1.0, 0.0, -1.0), 0.5, material_left)); - world.add(make_shared(point3( 1.0, 0.0, -1.0), 0.5, material_right)); + world.add( + make_shared(point3(0.0, -100.5, -1.0), 100.0, material_ground)); + world.add(make_shared(point3(0.0, 0.0, -1.0), 0.5, material_center)); + world.add(make_shared(point3(-1.0, 0.0, -1.0), 0.5, material_left)); + world.add(make_shared(point3(1.0, 0.0, -1.0), 0.5, material_right)); - // Camera + // Camera - camera cam; + camera cam; - // Render + // Render - std::cout << "P3\n" << image_width << " " << image_height << "\n255\n"; + std::cout << "P3\n" << image_width << " " << image_height << "\n255\n"; - for (int j = image_height-1; j >= 0; --j) { - std::cerr << "\rScanlines remaining: " << j << ' ' << std::flush; - for (int i = 0; i < image_width; ++i) { - color pixel_color(0, 0, 0); - for (int s = 0; s < samples_per_pixel; ++s) { - auto u = (i + random_double()) / (image_width-1); - auto v = (j + random_double()) / (image_height-1); - ray r = cam.get_ray(u, v); - pixel_color += ray_color(r, world, max_depth); - } - write_color(std::cout, pixel_color, samples_per_pixel); - } + for (int j = image_height - 1; j >= 0; --j) { + std::cerr << "\rScanlines remaining: " << j << ' ' << std::flush; + for (int i = 0; i < image_width; ++i) { + color pixel_color(0, 0, 0); + for (int s = 0; s < samples_per_pixel; ++s) { + auto u = (i + random_double()) / (image_width - 1); + auto v = (j + random_double()) / (image_height - 1); + ray r = cam.get_ray(u, v); + pixel_color += ray_color(r, world, max_depth); + } + write_color(std::cout, pixel_color, samples_per_pixel); } + } - std::cerr << "\nDone.\n"; + std::cerr << "\nDone.\n"; return 0; } diff --git a/rtiww/src/material.h b/rtiww/src/material.h index 7735998..c3837e5 100644 --- a/rtiww/src/material.h +++ b/rtiww/src/material.h @@ -13,46 +13,62 @@ public: color &attenuation, ray &scattered) const = 0; }; - - class lambertian : public material { public: - lambertian(const color& a) : albedo(a) {} + lambertian(const color &a) : albedo(a) {} - virtual bool scatter( - const ray& r_in, const hit_record& rec, color& attenuation, ray& scattered - ) const override { - auto scatter_direction = rec.normal+random_in_unit_sphere(); + virtual bool scatter(const ray &r_in, const hit_record &rec, + color &attenuation, ray &scattered) const override { + auto scatter_direction = rec.normal + random_in_unit_sphere(); - // Catch degenerate scatter direction - if (scatter_direction.near_zero()) - scatter_direction = rec.normal; + // Catch degenerate scatter direction + if (scatter_direction.near_zero()) + scatter_direction = rec.normal; - scattered = ray(rec.p, scatter_direction); - attenuation = albedo; - return true; - } + scattered = ray(rec.p, scatter_direction); + attenuation = albedo; + return true; + } public: - color albedo; + color albedo; }; class metal : public material { public: - metal(const color& a, double f) : albedo(a), fuzz(f<1 ? f: 1) {} + metal(const color &a, double f) : albedo(a), fuzz(f < 1 ? f : 1) {} - virtual bool scatter( - const ray& r_in, const hit_record& rec, color& attenuation, ray& scattered - ) const override { - vec3 reflected = reflect(unit_vector(r_in.direction()), rec.normal); - scattered = ray(rec.p, reflected + fuzz*random_in_unit_sphere()); - attenuation = albedo; - return true; - } + virtual bool scatter(const ray &r_in, const hit_record &rec, + color &attenuation, ray &scattered) const override { + vec3 reflected = reflect(unit_vector(r_in.direction()), rec.normal); + scattered = ray(rec.p, reflected + fuzz * random_in_unit_sphere()); + attenuation = albedo; + return true; + } public: - color albedo; - double fuzz; + color albedo; + double fuzz; +}; + +class dielectric : public material { +public: + dielectric(double index_of_refraction) : ir(index_of_refraction) {} + + virtual bool scatter(const ray &r_in, const hit_record &rec, + color &attenuation, ray &scattered) const override { + attenuation = color(1.0, 1.0, 1.0); + double refraction_ratio = rec.front_face ? (1.0 / ir) : ir; + + vec3 unit_direction = unit_vector(r_in.direction()); + vec3 refracted = refract(unit_direction, rec.normal, refraction_ratio); + + scattered = ray(rec.p, refracted); + return true; + } + +public: + double ir; }; #endif // MATERIAL_H_ diff --git a/rtiww/src/vec3.h b/rtiww/src/vec3.h index c38b002..869cc68 100644 --- a/rtiww/src/vec3.h +++ b/rtiww/src/vec3.h @@ -124,4 +124,11 @@ vec3 random_in_hemisphere(const vec3 &normal) { vec3 reflect(const vec3 &v, const vec3 &n) { return v - 2 * dot(v, n) * n; } +vec3 refract(const vec3 &v, const vec3 &n, double etai_over_etat) { + auto cos_theta = fmin(dot(-v, n), 1.0); + vec3 r_out_perp = etai_over_etat * (v + cos_theta * n); + vec3 r_out_parallel = -sqrt(fabs(1.0 - r_out_perp.length_squared())) * n; + return r_out_perp + r_out_parallel; +} + #endif // RTIWW_VEC3_H