additional materials

src/hittable.rs

@@ -50,7 +50,7 @@ impl HitRecord {
         Self::new(
             Point3::null(),
             Vec3::null(),
-            Arc::new(Metal::new(&Color::null())),
+            Arc::new(Metal::new(&Color::null(), 0.0)),
             0.0,
             false,
         )

src/main.rs

@@ -19,7 +19,7 @@ use std::env;
 use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::Arc;
 use vec3::{Color, Point3, Vec3};
-use material::{Material, Lambertian, Metal, Mirror};
+use material::{Material, Lambertian, Metal, Dielectric};
 
 fn ray_color(r: &Ray, world: &HittableList, depth: u32) -> Color {
     let mut rec = HitRecord::empty();
@@ -50,7 +50,7 @@ fn main() {
 
     // Image
     let aspect_ratio = 16.0 / 9.0;
-    let image_width = 1000;
+    let image_width = 1920;
     let image_height = (image_width as f64 / aspect_ratio) as u32;
     let samples_per_pixel = 100_u32;
     let max_depth = 50;
@@ -60,9 +60,12 @@ fn main() {
 
     let material_ground = Arc::new(Lambertian::new(&Color::new(0.8, 0.8, 0.0)));
     let material_center = Arc::new(Lambertian::new(&Color::new(0.7, 0.1, 0.2)));
+    //let material_center = Arc::new(Dielectric::new(1.5));
     let material_blue = Arc::new(Lambertian::new(&Color::new(0.2, 0.1, 0.7)));
-    let material_metal = Arc::new(Metal::new(&Color::new(0.8, 0.8, 0.8)));
-    let _material_mirror = Arc::new(Mirror::new(&Color::new(0.99, 0.99, 0.99)));
+    let material_metal = Arc::new(Metal::new(&Color::new(0.8, 0.8, 0.8), 0.1));
+    let material_metal_fuzz = Arc::new(Metal::new(&Color::new(0.8, 0.8, 0.8), 1.0));
+    let material_mirror = Arc::new(Metal::new(&Color::new(0.8, 0.8, 0.8), 0.0));
+    let material_dielectric = Arc::new(Dielectric::new(1.5));
 
 
 
@@ -72,24 +75,24 @@ fn main() {
         material_ground.clone(),
     )));
     world.add(Box::<Sphere>::new(Sphere::new(
-        Point3::new(0.0, -0.1, -1.0),
-        0.4,
+        Point3::new(0.0, 0.0, -1.0),
+        0.5,
         material_center.clone(),
     )));
     world.add(Box::<Sphere>::new(Sphere::new(
-        Point3::new(-1.0, 0.0, -1.0),
+        Point3::new(-1.0, -0.15, -1.0),
         0.5,
-        material_metal.clone(),
+        material_dielectric.clone(),
     )));
     world.add(Box::<Sphere>::new(Sphere::new(
-        Point3::new(1.3, 0.3, -1.5),
-        0.8,
-        material_metal.clone(),
+        Point3::new(1.0, 0.0, -1.0),
+        -0.4,
+        material_dielectric.clone(),
     )));
     world.add(Box::<Sphere>::new(Sphere::new(
         Point3::new(-1.5, 1.3, -1.7),
         0.4,
-        material_metal.clone(),
+        material_mirror.clone(),
     )));
     world.add(Box::<Sphere>::new(Sphere::new(
         Point3::new(-0.5, 0.5, 1.0),

src/material.rs

@@ -12,12 +12,17 @@ pub struct Lambertian {
 
 pub struct Metal {
     albedo: Color,
+    fuzz: f64,
 }
 
 pub struct Mirror {
     albedo: Color,
 }
 
+pub struct Dielectric {
+    ir: f64,
+}
+
 
 pub trait Material: Sync + Send {
     fn scatter(&self,r_in: &Ray, rec: &HitRecord, attenuation: &mut Color, scattered: &mut Ray) -> bool;
@@ -46,9 +51,10 @@ impl Material for Lambertian {
 }
 
 impl Metal {
-    pub fn new(a: &Color) -> Self {
+    pub fn new(a: &Color, f: f64) -> Self {
         Metal {
             albedo: *a,
+            fuzz: f,
         }
     }
 }
@@ -57,7 +63,7 @@ impl Material for Metal {
     fn scatter(&self, r_in: &Ray, rec: &HitRecord, attenuation: &mut Color, scattered: &mut Ray) -> bool {
         let reflected = Vec3::reflect(&Vec3::unit_vector(r_in.direction()), &rec.normal);
 
-        *scattered = Ray::new(rec.p, reflected);
+        *scattered = Ray::new(rec.p, reflected + self.fuzz*Vec3::random_in_unit_sphere());
         *attenuation = self.albedo.clone();
 
         return Vec3::dot(scattered.direction(), rec.normal) > 0.0;
@@ -91,3 +97,36 @@ impl Material for Mirror {
         };
     }
 }
+
+impl Dielectric {
+    pub fn new(index_of_refraction: f64) -> Self {
+        Dielectric {
+            ir: index_of_refraction,
+        }
+    }
+
+    fn reflectance(cosine: f64, ref_idx: f64) -> f64 {
+        let r0 = ((1.0-ref_idx) / (1.0+ref_idx)).powi(2);
+        return r0 + (1.0-r0)*(1.0 - cosine).powi(5);
+    }
+}
+
+impl Material for Dielectric {
+    fn scatter(&self, r_in: &Ray, rec: &HitRecord, attenuation: &mut Color, scattered: &mut Ray) -> bool {
+        *attenuation = Color::new(1.0, 1.0, 1.0);
+        let refraction_ratio = if rec.front_face { 1.0 / self.ir } else { self.ir };
+
+        let unit_direction = Vec3::unit_vector(r_in.direction());
+        let cos_theta = Vec3::dot(-1.0 * unit_direction, rec.normal).min(1.0);
+        let sin_theta = (1.0 - cos_theta*cos_theta).sqrt();
+
+        let mut direction = Vec3::refract(&unit_direction, &rec.normal, refraction_ratio); // can reflect
+
+        if refraction_ratio * sin_theta > 1.0 || Dielectric::reflectance(cos_theta, refraction_ratio) > utility::random_f64() { // must reflect
+            direction = Vec3::reflect(&unit_direction, &rec.normal);
+        }
+
+        *scattered = Ray::new(rec.p, direction);
+        return true;
+    }
+}

src/vec3.rs

@@ -50,6 +50,13 @@ impl Vec3 {
         *v - 2.0*Self::dot(*v, *n) * *(n)
     }
 
+    pub fn refract(uv: &Self, n: &Self, etai_over_etat: f64) -> Self {
+        let cos_theta = Self::dot(-1.0 * *uv, *n).min(1.0); // Minimum aus 1.0 und Punktprodukt
+        let r_out_perp = etai_over_etat * (*uv + cos_theta * *n);
+        let r_out_parallel = -(1.0 - r_out_perp.length_squared()).abs().sqrt() * *n;
+        return r_out_perp + r_out_parallel;
+    }
+
     pub fn near_zero(&self) -> bool {
         let s = 1e-8;
         return (self.e[0].abs() < s) && (self.e[1].abs() < s) && (self.e[2].abs() < s);