diff options
| -rw-r--r-- | src/main.zig | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/src/main.zig b/src/main.zig index 387e3f7..a501847 100644 --- a/src/main.zig +++ b/src/main.zig @@ -195,8 +195,14 @@ const DielectricMaterial = struct { _ = rand; const refraction_ratio = if (record.front_face) 1.0 / mat.ir else mat.ir; const unit_dir = r_in.dir.normalized(); - const refracted = refract(unit_dir, record.normal, refraction_ratio); - scattered.* = Ray{ .origin = record.p, .dir = refracted }; + + const cos_theta = @min(unit_dir.mul(-1.0).dot(record.normal), 1.0); + const sin_theta = @sqrt(1.0 - cos_theta * cos_theta); + // sin(theta') = refraction_ratio * sin(theta) <= 1 + const can_refract = refraction_ratio * sin_theta <= 1.0; + + const dir = if (can_refract) refract(unit_dir, record.normal, refraction_ratio) else reflect(unit_dir, record.normal); + scattered.* = Ray{ .origin = record.p, .dir = dir }; attenuation.* = Color{ .x = 1.0, .y = 1.0, .z = 1.0 }; return true; } @@ -386,9 +392,9 @@ pub fn main() !void { // World const material_ground = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 0.8, .y = 0.8, .z = 0.0 } } }; - const material_center = Material{ .dielectric = DielectricMaterial{ .ir = 1.5 } }; - const material_left = Material{ .dielectric = DielectricMaterial{ .ir = 1.1 } }; - const material_right = Material{ .metal = MetalMaterial{ .albedo = Color{ .x = 0.8, .y = 0.6, .z = 0.2 }, .fuzz = 1.0 } }; + const material_center = Material{ .diffuse = DiffuseMaterial{ .albedo = Color{ .x = 0.1, .y = 0.2, .z = 0.5 } } }; + const material_left = Material{ .dielectric = DielectricMaterial{ .ir = 1.5 } }; + const material_right = Material{ .metal = MetalMaterial{ .albedo = Color{ .x = 0.8, .y = 0.6, .z = 0.2 }, .fuzz = 0.0 } }; const sphere1 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 0.0, .y = -100.5, .z = -1.0 }, .radius = 100.0, .material = &material_ground } }; const sphere2 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = 0.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_center } }; const sphere3 = Hittable{ .sphere = Sphere{ .center = Point3{ .x = -1.0, .y = 0.0, .z = -1.0 }, .radius = 0.5, .material = &material_left } }; |