Trying to figure out perlin noise

Cargo.toml

@@ -4,7 +4,6 @@ version = "0.1.0"
 authors = ["ishanjain28 <ishanjain28@gmail.com>"]
 edition = "2018"
 
-
 [features]
 default = ["gui"]
 gui = ["sdl2"]

src/demos/mod.rs

@@ -12,9 +12,11 @@ use std::{
 };
 
 mod checkered_motion_blur;
+mod perlin_noise_ball;
 mod two_spheres;
 
 pub use checkered_motion_blur::CheckeredMotionBlur;
+pub use perlin_noise_ball::PerlinNoiseBall;
 pub use two_spheres::TwoSpheres;
 
 #[derive(Debug)]

src/demos/perlin_noise_ball.rs

@@ -0,0 +1,61 @@
+use std::sync::Arc;
+
+use rand::{prelude::SmallRng, SeedableRng};
+
+use crate::{
+    demos::{Demo, ParallelHit},
+    materials::Lambertian,
+    shapes::Sphere,
+    texture::PerlinNoise,
+    types::Vec3,
+    BvhNode, Camera,
+};
+
+pub struct PerlinNoiseBall {}
+
+impl Demo for PerlinNoiseBall {
+    type DemoT = BvhNode<Arc<dyn ParallelHit>>;
+
+    fn name(&self) -> &'static str {
+        "perlin_noise"
+    }
+
+    fn world(&self) -> Self::DemoT {
+        let mut world: Vec<Arc<dyn ParallelHit>> = Vec::with_capacity(500);
+
+        let mut rng = rand::thread_rng();
+        let mut rng = SmallRng::from_rng(&mut rng).unwrap();
+
+        world.push(Arc::new(Sphere::new(
+            Vec3::new(0.0, -1000.0, 0.0),
+            1000.0,
+            Lambertian::new(PerlinNoise::new(&mut rng)),
+        )));
+
+        world.push(Arc::new(Sphere::new(
+            Vec3::new(0.0, 2.0, 0.0),
+            2.0,
+            Lambertian::new(PerlinNoise::new(&mut rng)),
+        )));
+
+        BvhNode::new(&mut rng, &mut world, 0.0, 1.0)
+    }
+
+    fn camera(&self, aspect_ratio: f64) -> Camera {
+        let lookfrom = Vec3::new(13.0, 2.0, 3.0);
+        let lookat = Vec3::new(0.0, 0.0, 0.0);
+        let aperture = 0.1;
+        let focus_distance = 10.0;
+        Camera::new(
+            lookfrom,
+            lookat,
+            Vec3::new(0.0, 1.0, 0.0),
+            20.0,
+            aspect_ratio,
+            aperture,
+            focus_distance,
+            0.0,
+            1.0,
+        )
+    }
+}

src/main.rs

@@ -23,7 +23,7 @@ use demos::Demo;
 
 use std::time::Instant;
 
-const NUM_SAMPLES: u8 = 25;
+const NUM_SAMPLES: u8 = 255;
 const VERTICAL_PARTITION: usize = 12;
 const HORIZONTAL_PARTITION: usize = 12;
 const WIDTH: usize = 1920;
@@ -68,7 +68,7 @@ fn run(mut width: usize, mut height: usize) -> Result<(), String> {
         .map_err(|e| e.to_string())?;
 
     let mut active_demo: &dyn Demo<DemoT = BvhNode<Arc<dyn ParallelHit>>> =
-        &demos::CheckeredMotionBlur {};
+        &demos::PerlinNoiseBall {};
     let mut should_update = true;
 
     loop {
@@ -93,6 +93,10 @@ fn run(mut width: usize, mut height: usize) -> Result<(), String> {
                             active_demo = &demos::TwoSpheres {};
                             should_update = true;
                         }
+                        Some(Keycode::Num3) => {
+                            active_demo = &demos::PerlinNoiseBall {};
+                            should_update = true;
+                        }
                         None => unreachable!(),
                         _ => (),
                     };
@@ -130,9 +134,11 @@ fn run(mut width: usize, mut height: usize) -> Result<(), String> {
 
 #[cfg(not(feature = "gui"))]
 fn run(width: usize, height: usize) -> Result<(), String> {
-    run_and_save_demo(demos::CheckeredMotionBlur {}, width, height);
+    //    run_and_save_demo(demos::CheckeredMotionBlur {}, width, height);
 
-    run_and_save_demo(demos::TwoSpheres {}, width, height);
+    //run_and_save_demo(demos::TwoSpheres {}, width, height);
+
+    run_and_save_demo(demos::PerlinNoiseBall {}, width, height);
 
     Ok(())
 }

src/materials/lambertian.rs

@@ -21,9 +21,9 @@ impl<T: Texture + Send + Sync> Material for Lambertian<T> {
         let scatter_direction = hit_rec.normal + random_point_in_unit_sphere(rng);
         let scattered_ray = Ray::new(hit_rec.p, scatter_direction, ray.time());
 
-        let mut p = hit_rec.p;
-        self.albedo.value(hit_rec.u, hit_rec.v, &mut p);
-
-        (p, Some(scattered_ray))
+        (
+            self.albedo.value(hit_rec.u, hit_rec.v, &hit_rec.p),
+            Some(scattered_ray),
+        )
     }
 }

src/texture/checker.rs

@@ -12,7 +12,7 @@ impl<T: Texture> Checker<T> {
 }
 
 impl<T: Texture> Texture for Checker<T> {
-    fn value(&self, u: f64, v: f64, p: &mut Vec3) {
+    fn value(&self, u: f64, v: f64, p: &Vec3) -> Vec3 {
         let sine_wave = f64::sin(10.0 * p.x()) * f64::sin(10.0 * p.y()) * f64::sin(10.0 * p.z());
 
         if sine_wave < 0.0 {

src/texture/mod.rs

@@ -1,11 +1,15 @@
 mod checker;
+mod perlin;
+mod perlin_noise;
 mod solid;
 
 pub use checker::Checker;
+pub use perlin::Perlin;
+pub use perlin_noise::PerlinNoise;
 pub use solid::Solid;
 
 use crate::types::Vec3;
 
 pub trait Texture {
-    fn value(&self, u: f64, v: f64, p: &mut Vec3);
+    fn value(&self, u: f64, v: f64, p: &Vec3) -> Vec3;
 }

src/texture/perlin.rs

@@ -0,0 +1,70 @@
+use crate::types::Vec3;
+use rand::{distributions::Uniform, Rng};
+
+const POINT_COUNT: usize = 256;
+
+pub struct Perlin {
+    points: Vec<f64>,
+
+    permute_x: Vec<usize>,
+    permute_y: Vec<usize>,
+    permute_z: Vec<usize>,
+}
+
+impl Perlin {
+    pub fn new<R: Rng + ?Sized>(rng: &mut R) -> Self {
+        let mut points = vec![0.0; POINT_COUNT];
+
+        for p in points.iter_mut() {
+            *p = rng.gen_range(0.0..=1.0)
+        }
+
+        let permute_x = Self::perlin_generate_permutation(rng);
+        let permute_y = Self::perlin_generate_permutation(rng);
+        let permute_z = Self::perlin_generate_permutation(rng);
+
+        Self {
+            points,
+            permute_x,
+            permute_y,
+            permute_z,
+        }
+    }
+
+    fn perlin_generate_permutation<R: Rng + ?Sized>(rng: &mut R) -> Vec<usize> {
+        let mut p = (0..POINT_COUNT).collect::<Vec<usize>>();
+        permute(rng, &mut p);
+        p
+    }
+
+    pub fn noise(&self, p: &Vec3) -> f64 {
+        let i = (4.0 * p.x()) as usize & 255;
+        let j = (4.0 * p.y()) as usize & 255;
+        let k = (4.0 * p.z()) as usize & 255;
+
+        //        if p.x() > 1.0 && p.y() > 1.0 && p.z() > 1.0 {
+        //            println!(
+        //                "p = {} i = {} j = {} k = {} pi = {} pj = {} pk = {} point = {}",
+        //                p,
+        //                i,
+        //                j,
+        //                k,
+        //                self.permute_x[i],
+        //                self.permute_x[j],
+        //                self.permute_x[k],
+        //                self.points[self.permute_x[i] ^ self.permute_y[j] ^ self.permute_z[k]]
+        //            );
+        //        }
+
+        self.points[self.permute_x[i] ^ self.permute_y[j] ^ self.permute_z[k]]
+    }
+}
+
+fn permute<R: Rng + ?Sized>(rng: &mut R, p: &mut [usize]) {
+    let l = p.len();
+
+    for i in (0..l).rev() {
+        let r = rng.gen_range(0..=i);
+        p.swap(i, r);
+    }
+}

src/texture/perlin_noise.rs

@@ -0,0 +1,21 @@
+use rand::Rng;
+
+use crate::{texture::Perlin, types::Vec3, Texture};
+
+pub struct PerlinNoise {
+    noise: Perlin,
+}
+
+impl PerlinNoise {
+    pub fn new<R: Rng + ?Sized>(rng: &mut R) -> Self {
+        Self {
+            noise: Perlin::new(rng),
+        }
+    }
+}
+
+impl Texture for PerlinNoise {
+    fn value(&self, _u: f64, _v: f64, p: &Vec3) -> Vec3 {
+        Vec3::new(1.0, 1.0, 1.0) * self.noise.noise(p)
+    }
+}

src/texture/solid.rs

@@ -11,7 +11,7 @@ impl Solid {
 }
 
 impl Texture for Solid {
-    fn value(&self, _u: f64, _v: f64, p: &mut Vec3) {
-        *p = self.color
+    fn value(&self, _u: f64, _v: f64, _p: &Vec3) -> Vec3 {
+        self.color
     }
 }