rm: unimplemented cylinder code

.gitignore

@@ -1,3 +1,4 @@
 /target
-output.png
+*.png
 .env
+!textures/*.png

scenes/bench.json

@@ -0,0 +1,38 @@
+{
+  "filename": "testing.png",
+  "image_width": 800,
+  "image_height": 600,
+  "max_depth": 50,
+  "camera": { 
+    "anti_alias_rate": 16,
+    "fov": 70.0,
+    "look_from": [-10, 1, 15],
+    "look_at": [-11.0, 7.0, 0.0], 
+    "vup": [0.0, 1.0, 0.0],
+    "defocus_angle": 0,
+    "focus_dist": 15.68
+  },
+  "materials": [
+    { "type": "lambertian", "albedo": [0.2, 0.2, 0.2], "prob": 0.8 },
+    { "type": "lambertian", "albedo": [0.9, 0.9, 0.0], "prob": 1.0, "fuzz": 0.1 },
+    { "type": "dielectric", "refraction_index": 1.5},
+    { "type": "normal"}
+ ],
+  "objects": [
+    { "type": "sphere", "center": [0.0, 0.0, -1.2], "radius": 0.5, "material": { "type": "metal", "albedo": [0.7, 0.4, 0.2], "prob": 1.0, "fuzz": 0.1 }},
+    { "type": "sphere", "center": [-1, 0, -1], "radius": 0.4, "material": 3},
+    { "type": "sphere", "center": [1, 0, -1], "radius": 0.5, "material": { "type": "metal", "albedo": [0.8, 0.6, 0.2], "prob": 1.0, "fuzz": 1.0 }},
+    { "type": "triangle", "p1": [-4, 0, -4], "p2": [0, 0, -4], "p3": [-2, 2, -4], "material": 1},
+    { "type": "triangle", "p1": [0, 0, -4], "p2": [4, 0, -4], "p3": [2, 2, -4], "material": 1},
+    { "type": "triangle", "p1": [-2, 2, -4], "p2": [2, 2, -4], "p3": [0, 4, -4], "material": 3},
+    { "type": "quad", "p1": [-20, -1, -20], "p2": [20, -1, -20], "p3": [20, 20, -20], "p4": [-20, 20, -20], "material": 0},
+    { "type": "quad", "p1": [-20, -1, 20], "p2": [-20, -1, -20], "p3": [-20, 20, -20], "p4": [-20, 20, 20], "material": 0},
+    { "type": "quad", "p1": [-20, -1, 20], "p2": [20, -1, 20], "p3": [20, -1, -20], "p4": [-20, -1, -20], "material": 0},
+    { "type": "quad", "p1": [20, -1, 20], "p2": [20, -1, -20], "p3": [20, 20, -20], "p4": [20, 20, 20], "material": 0},
+    { "type": "cube", "p1": [8, 0, 2], "p2": [12, 0, 2], "p3": [12, 4, 2], "p4": [8, 4, 2], "p5": [8, 0, -2], "p6": [12, 0, -2], "p7": [12, 4, -2], "p8": [8, 4, -2], "material": 3},
+    { "type": "circle", "center": [-9, 3, 0], "radius": 3, "normal": [0, 1, 0.5], "material": {"type": "metal", "albedo": [0.9, 0.9, 0.9], "prob": 1.0, "fuzz": 0.3}}
+ ]
+}
+
+
+

scenes/texture.json

@@ -0,0 +1,35 @@
+{
+  "filename": "textured.png",
+  "image_width": 1920,
+  "image_height": 1080,
+  "max_depth": 50,
+  "camera": { 
+    "anti_alias_rate": 2,
+    "fov": 50.0,
+    "look_from": [-3, 4, 10],
+    "look_at": [-3, 0.0, -10.0], 
+    "vup": [0.0, 1.0, 0.0],
+    "defocus_angle": 0,
+    "focus_dist": 15.68
+  },
+  "materials": [
+    { "type": "lambertian", "albedo": [0.2, 0.2, 0.2], "prob": 0.8 },
+    {"type": "texture", "source": "./textures/earthmap1k.png"},
+    {"type": "texture", "source": "./textures/bluegrid.png"}
+ ],
+  "objects": [
+    { "type": "sphere", "center": [0.0, 0.0, -1.2], "radius": 0.9, "material": 2},
+    { "type": "sphere", "center": [-2, 0, -1], "radius": 0.8, "material": 1},
+    { "type": "triangle", "p1": [0, 0, -4], "p2": [4, 0, -4], "p3": [2, 2, -4], "material": 2},
+    { "type": "triangle", "p1": [-2, 2, -4], "p2": [2, 2, -4], "p3": [0, 4, -4], "material": 1},
+    { "type": "quad", "p1": [-20, -1, -20], "p2": [20, -1, -20], "p3": [20, 20, -20], "p4": [-20, 20, -20], "material": 0},
+    { "type": "quad", "p1": [-20, -1, 20], "p2": [-20, -1, -20], "p3": [-20, 20, -20], "p4": [-20, 20, 20], "material": 0},
+    { "type": "quad", "p1": [-20, -1, 20], "p2": [20, -1, 20], "p3": [20, -1, -20], "p4": [-20, -1, -20], "material": 0},
+    { "type": "quad", "p1": [20, -1, 20], "p2": [20, -1, -20], "p3": [20, 20, -20], "p4": [20, 20, 20], "material": 0},
+    { "type": "quad", "p1": [-4, 3, -4], "p2": [-1, 3, -4], "p3": [-1, 6, -4], "p4": [-4, 6, -4], "material": 1},
+    { "type": "quad", "p1": [-8, 3, -4], "p2": [-5, 3, -4], "p3": [-5, 6, -4], "p4": [-8, 6, -4], "material": 2}
+ ]
+}
+
+
+

src/camera.rs

@@ -5,19 +5,19 @@ use crate::{ray::Ray, vec3::Vec3};
 #[derive(Debug)]
 pub struct Camera {
     // raytracing
-    pub anti_alias_rate: u32,
+    anti_alias_rate: u32,
-    pub pixel00_loc: Vec3,
+    pixel00_loc: Vec3,
-    pub pixel_delta_u: Vec3,
+    pixel_delta_u: Vec3,
-    pub pixel_delta_v: Vec3,
+    pixel_delta_v: Vec3,
 
     // camera
     dirty: bool,
-    pub fov: f32,
+    fov: f32,
-    pub look_from: Vec3,
+    look_from: Vec3,
-    pub look_at: Vec3,
+    look_at: Vec3,
     vup: Vec3,
-    pub defocus_angle: f32,
+    defocus_angle: f32,
-    pub focus_dist: f32,
+    focus_dist: f32,
 
     // camera helpers
     u: Vec3,
@@ -83,7 +83,7 @@ impl Camera {
         }
     }
 
-    pub fn init(&mut self, w: f32, hi: f32) {
+    pub fn init(&mut self, width: u32, height: u32) {
         if !self.dirty {
             return;
         }
@@ -97,13 +97,13 @@ impl Camera {
 
         // viewport
         let viewport_height = 2. * h * self.focus_dist;
-        let viewport_width = viewport_height * (w / hi);
+        let viewport_width = viewport_height * (width as f32 / height as f32);
         let viewport_u = viewport_width * self.u;
         let viewport_v = viewport_height * -self.v;
 
         // variables
-        self.pixel_delta_u = viewport_u / w;
+        self.pixel_delta_u = viewport_u / width;
-        self.pixel_delta_v = viewport_v / hi;
+        self.pixel_delta_v = viewport_v / height;
         self.pixel00_loc =
             self.look_from - (self.focus_dist * self.w) - viewport_u / 2. - viewport_v / 2.;
         self.dirty = false;
@@ -115,6 +115,14 @@ impl Camera {
         }
     }
 
+    pub fn get_anti_alias_rate(&self) -> u32 {
+        self.anti_alias_rate
+    }
+
+    pub fn get_pixel_tl(&self, x: u32, y: u32) -> Vec3 {
+        self.pixel00_loc + (x * self.pixel_delta_u) + (y * self.pixel_delta_v)
+    }
+
     pub fn get_ray(&self, pixel_tl: Vec3, x: u32, y: u32) -> Ray {
         let pixel_loc = pixel_tl
             + (x * self.pixel_delta_u / (self.anti_alias_rate + 1) as f32)

src/main.rs

@@ -8,26 +8,19 @@ mod scenes;
 mod vec3;
 
 use std::{env, fs};
-use std::sync::Arc;
 
-use crate::camera::Camera;
-use crate::objects::materials::dielectric::Dielectric;
-use crate::objects::materials::lambertian::{Lambertian, Metal};
-use crate::objects::sphere::Sphere;
-use crate::objects::traits::Hittable;
 use crate::ray::Ray;
 use crate::raytracer::render;
 use crate::scenes::scene::Scene;
 use crate::vec3::Vec3;
 use dotenv::dotenv;
-use rand::RngExt;
 
 // TODO: implement scene serialization
 fn main() {
     dotenv().ok();
     pretty_env_logger::init();
 
-    // TODO: better cli parsing
+    // TODO: better cli parsing || add random flag to generate random scene
     let mut json_file = "./scenes/scene.json";
     let args: Vec<String> = env::args().collect();
     if args.len() > 1 {
@@ -36,93 +29,6 @@ fn main() {
 
     let json_str = fs::read_to_string(json_file).expect("Reading specified scene file failed!");
     let mut scene: Scene = serde_json::from_str(&json_str).unwrap();
+    let mut scene: Scene = Scene::random();
     render(&mut scene);
-    return;
-
-    // random spheres code; thought: make this available as cli flag?
-    let ground = Lambertian::rgb(-2.5, 0.5, 0.5, 1.);
-    let mut world: Vec<Arc<dyn Hittable>> = vec![Arc::new(Sphere::xyz(
-        0.,
-        -1000.,
-        0.,
-        1000.,
-        Arc::new(ground),
-    ))];
-
-    let mut rng = rand::rng();
-    let point = Vec3::new(4., 0.2, 0.);
-    for a in -11..11 {
-        for b in -11..11 {
-            let mat = rng.random_range((0.)..1.);
-            let center = Vec3::new(
-                a as f32 + 0.9 * rng.random_range((0.)..1.),
-                0.2,
-                b as f32 + 0.9 * rng.random_range((0.)..1.),
-            );
-
-            if (center - point).length() > 0.9 {
-                if mat < 0.8 {
-                    // diffuse
-                    world.push(Arc::new(Sphere::new(
-                        center,
-                        0.2,
-                        Arc::new(Lambertian::new(Vec3::random() * Vec3::random(), 1.)),
-                    )));
-                } else if mat < 0.95 {
-                    // metal
-                    world.push(Arc::new(Sphere::new(
-                        center,
-                        0.2,
-                        Arc::new(Metal::rgb(
-                            rng.random_range(0.5..1.),
-                            rng.random_range(0.5..1.),
-                            rng.random_range(0.5..1.),
-                            1.,
-                            rng.random_range((0.)..0.5),
-                        )),
-                    )));
-                } else {
-                    // glass
-                    world.push(Arc::new(Sphere::new(
-                        center,
-                        0.2,
-                        Arc::new(Dielectric::new(1.5)),
-                    )));
-                }
-            }
-        }
-    }
-
-    world.push(Arc::new(Sphere::xyz(
-        0.,
-        1.,
-        0.,
-        1.,
-        Arc::new(Dielectric::new(1.5)),
-    )));
-    world.push(Arc::new(Sphere::xyz(
-        -4.,
-        1.,
-        0.,
-        1.,
-        Arc::new(Lambertian::rgb(0.4, 0.2, 0.1, 1.)),
-    )));
-    world.push(Arc::new(Sphere::xyz(
-        4.,
-        1.,
-        0.,
-        1.,
-        Arc::new(Metal::rgb(0.7, 0.6, 0.5, 1., 0.)),
-    )));
-
-    let mut c = Camera::new();
-    c.set_fov(20.);
-    c.set_anti_alias_rate(23);
-    c.set_vup(Vec3::new(0., 1., 0.));
-    c.set_look_from(Vec3::new(13., 2., 3.));
-    c.set_look_at(Vec3::new(0., 0., 0.));
-    c.add_defocus_blur(0.6, 10.);
-
-    let mut s = Scene::new(c, world, "output.png".to_string(), 1920, 1080, 50);
-    render(&mut s);
 }

src/objects/circle.rs

@@ -1,4 +1,4 @@
-use std::sync::Arc;
+use std::{f32::consts::PI, sync::Arc};
 
 use crate::{
     objects::{materials::traits::Material, traits::Hittable},
@@ -45,8 +45,27 @@ impl Hittable for Circle {
 
         let p = r.at(t);
         if (p - self.center).length() < self.radius {
-            return Some(Hit::new(t, p, self.normal, self.material.clone(), self.normal.dot(&r.dir()) < 0.)); 
+            let uv = self.to_uv(&p);
+            return Some(Hit::new(
+                t,
+                p,
+                self.normal,
+                self.material.clone(),
+                self.normal.dot(r.dir()) < 0.,
+                *uv.x(),
+                *uv.y(),
+            ));
         }
         None
     }
+
+    fn to_uv(&self, point: &Vec3) -> Vec3 {
+        let p = *point - self.center;
+        // TODO: add rotated texture support
+        Vec3::new(
+            0.5 + p.y().atan2(*p.x()) / (2. * PI),
+            1. - (p.z() / self.radius).acos() / PI,
+            0.0,
+        )
+    }
 }

src/objects/cube.rs

@@ -41,4 +41,9 @@ impl Hittable for Cube {
     fn hit(&self, r: &Ray) -> Option<Hit> {
         Hit::hit_list(&self.faces, r)
     }
+
+    fn to_uv(&self, _point: &Vec3) -> Vec3 {
+        // TODO: map to [0.1] relative to specific face
+        todo!()
+    }
 }

src/objects/cylinder.rs

@@ -1,26 +0,0 @@
-use crate::{objects::traits::Hittable, vec3::Vec3};
-
-#[derive(Debug)]
-pub struct Cylinder {
-    radius: f32,
-    length: f32,
-    up: Vec3,
-    bottom_center: Vec3,
-}
-
-impl Cylinder {
-    pub fn new(radius: f32, length: f32, up: Vec3, bottom_center: Vec3) -> Self {
-        Self {
-            radius,
-            length,
-            up,
-            bottom_center,
-        }
-    }
-}
-
-impl Hittable for Cylinder {
-    fn hit(&self, r: &crate::ray::Ray) -> Option<super::hit::Hit> {
-        todo!()
-    }
-}

src/objects/hit.rs

@@ -12,16 +12,47 @@ pub struct Hit {
     n: Vec3,
     mat: Arc<dyn Material>,
     front_face: bool,
+    u: f32,
+    v: f32,
 }
 
 impl Hit {
-    pub fn new(t: f32, p: Vec3, n: Vec3, mat: Arc<dyn Material>, front_face: bool) -> Self {
+    pub fn new(
+        t: f32,
+        p: Vec3,
+        n: Vec3,
+        mat: Arc<dyn Material>,
+        front_face: bool,
+        u: f32,
+        v: f32,
+    ) -> Self {
         Self {
             t,
             p,
             n: if front_face { n } else { -n },
             mat,
             front_face,
+            u,
+            v,
+        }
+    }
+
+    pub fn from_minimal(
+        mh: MinimalHit,
+        n: Vec3,
+        mat: Arc<dyn Material>,
+        front_face: bool,
+        u: f32,
+        v: f32,
+    ) -> Self {
+        Self {
+            t: mh.t,
+            p: mh.p,
+            n,
+            mat,
+            front_face,
+            u,
+            v,
         }
     }
 
@@ -45,6 +76,10 @@ impl Hit {
         self.front_face
     }
 
+    pub fn uv(&self) -> (f32, f32) {
+        (self.u, self.v)
+    }
+
     // TODO: use front_face to discard back-hits for culling
     pub fn hit_list(hittables: &Vec<Arc<dyn Hittable>>, r: &Ray) -> Option<Hit> {
         let mut closest: Option<Hit> = None;
@@ -61,3 +96,22 @@ impl Hit {
         closest
     }
 }
+
+pub struct MinimalHit {
+    t: f32,
+    p: Vec3,
+}
+
+impl MinimalHit {
+    pub fn new(t: f32, p: Vec3) -> Self {
+        Self { t, p }
+    }
+
+    pub fn t(&self) -> f32 {
+        self.t
+    }
+
+    pub fn p(&self) -> &Vec3 {
+        &self.p
+    }
+}

src/objects/materials.rs

@@ -2,3 +2,4 @@ pub mod dielectric;
 pub mod lambertian;
 pub mod normal;
 pub mod traits;
+pub mod texture;

src/objects/materials/texture.rs

@@ -0,0 +1,80 @@
+use image::{DynamicImage, ImageReader};
+use log::trace;
+
+use crate::{
+    objects::{hit::Hit, materials::traits::Material},
+    ray::Ray,
+    vec3::Vec3,
+};
+
+// TODO: overhaul texture implementation so we can support textures for arbitrary materials.
+// Basically remove this struct, and instead make lambertian/metal/dielectric/take either a texture
+// or a flat colour
+// I think we can use an enum ColourSource with a function to fetch a specific colour depending on
+// if we have a texture/flat colour. and yeah.
+#[derive(Debug)]
+pub struct Texture {
+    source: DynamicImage,
+    width: u32,
+    height: u32,
+    stride: usize,
+}
+
+impl Texture {
+    pub fn new(texture: &str) -> Self {
+        let img = ImageReader::open(texture).unwrap().decode().unwrap(); // FIXME: unwraps
+        trace!(
+            "texture '{}' is {} by {} pixels, with {} bytes total",
+            texture,
+            img.width(),
+            img.height(),
+            img.as_bytes().len()
+        );
+        let stride = match img.color() {
+            // TODO: support other types of image
+            image::ColorType::L8 => todo!(),
+            image::ColorType::La8 => todo!(),
+            image::ColorType::Rgb8 => 3,
+            image::ColorType::Rgba8 => 4,
+            image::ColorType::L16 => todo!(),
+            image::ColorType::La16 => todo!(),
+            image::ColorType::Rgb16 => todo!(),
+            image::ColorType::Rgba16 => todo!(),
+            image::ColorType::Rgb32F => todo!(),
+            image::ColorType::Rgba32F => todo!(),
+            _ => 3,
+        };
+        Self {
+            width: img.width(),
+            height: img.height(),
+            source: img,
+            stride,
+        }
+    }
+
+    fn _idx(&self, u: f32, v: f32) -> usize {
+        let x: usize = (u * ((self.width - 1) as f32)) as usize; 
+        let y: usize = (v * ((self.height - 1) as f32)) as usize;
+
+        y * self.width as usize + x
+    }
+
+    fn _at(&self, u: f32, v: f32) -> Vec3 {
+        let b = self.source.as_bytes();
+        let idx = self._idx(u, v);
+
+        Vec3::from_u8(
+            b[self.stride * idx],
+            b[self.stride * idx + 2],
+            b[self.stride * idx + 1],
+        )
+    }
+}
+
+impl Material for Texture {
+    fn scatter(&self, hit: &Hit, _ray: &Ray) -> Option<(Option<Ray>, Vec3)> {
+        let (u, v) = hit.uv();
+        let col = self._at(u, 1. - v);
+        Some((None, col))
+    }
+}

src/objects/quad.rs

@@ -13,6 +13,10 @@ pub struct Quad {
     p4: Vec3,
     material: Arc<dyn Material>,
     normal: Vec3,
+
+    // helpers
+    t1: Triangle,
+    t2: Triangle,
 }
 
 impl Quad {
@@ -22,27 +26,12 @@ impl Quad {
             p2,
             p3,
             p4,
-            material,
+            material: material.clone(),
             normal: (p2 - p1).cross(&(p4 - p1)).get_unit(),
+            t1: Triangle::new(p1, p2, p4, material.clone()),
+            t2: Triangle::new(p2, p3, p4, material),
         }
     }
-
-    pub fn hit(
-        p1: Vec3,
-        p2: Vec3,
-        p3: Vec3,
-        p4: Vec3,
-        material: Arc<dyn Material>,
-        normal: Vec3,
-        r: &Ray,
-    ) -> Option<Hit> {
-        let isct1 = Triangle::hit(p1, p2, p4, material.clone(), normal, r);
-        let isct2 = Triangle::hit(p2, p3, p4, material.clone(), normal, r);
-        if isct1.is_some() {
-            return isct1;
-        }
-        isct2
-    }
 }
 
 impl Debug for Quad {
@@ -59,14 +48,22 @@ impl Debug for Quad {
 
 impl Hittable for Quad {
     fn hit(&self, r: &Ray) -> Option<Hit> {
-        Quad::hit(
+        let mh = self.t1.calculate_hit(r).or(self.t2.calculate_hit(r))?;
-            self.p1,
+        let uvw = self.to_uv(mh.p());
-            self.p2,
+
-            self.p3,
+        Some(Hit::from_minimal(
-            self.p4,
+            mh,
-            self.material.clone(),
             self.normal,
-            r,
+            self.material.clone(),
-        )
+            false,
+            *uvw.x(),
+            *uvw.y(),
+        ))
+    }
+
+    fn to_uv(&self, point: &Vec3) -> Vec3 {
+        let u = (*point - self.p1).dot(&(self.p2 - self.p1)) / (self.p2 - self.p1).length_squared();
+        let v = (*point - self.p1).dot(&(self.p4 - self.p1)) / (self.p4 - self.p1).length_squared();
+        Vec3::new(u, v, 0.)
     }
 }

src/objects/sphere.rs

@@ -1,4 +1,5 @@
 use core::f32::math::sqrt;
+use std::f32::consts::PI;
 use std::fmt::{self, Debug};
 use std::sync::Arc;
 
@@ -14,7 +15,6 @@ pub struct Sphere {
     material: Arc<dyn Material>,
 }
 
-
 impl Debug for Sphere {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Sphere")
@@ -59,13 +59,26 @@ impl Hittable for Sphere {
             let t = if tl > 0.001 { tl } else { tr };
             let p = r.at(t);
             let out_n = (p - self.center) / self.radius;
+            let uv = self.to_uv(&p);
             Some(Hit::new(
                 t,
                 p,
                 (p - self.center).get_unit(),
                 self.material.clone(),
                 out_n.dot(r.dir()) < 0.,
+                *uv.x(),
+                *uv.y(),
             ))
         }
     }
+
+    fn to_uv(&self, point: &Vec3) -> Vec3 {
+        let p = *point - self.center;
+        // TODO: add rotated texture support
+        Vec3::new(
+            0.5 + p.y().atan2(*p.x()) / (2. * PI),
+            1. - (p.z() / self.radius).acos() / PI,
+            0.0,
+        )
+    }
 }

src/objects/traits.rs

@@ -2,7 +2,9 @@ use std::fmt::Debug;
 
 use crate::Ray;
 use crate::objects::hit::Hit;
+use crate::vec3::Vec3;
 
 pub trait Hittable: Debug + Send + Sync {
+    fn to_uv(&self, point: &Vec3) -> Vec3; 
     fn hit(&self, r: &Ray) -> Option<Hit>;
 }

src/objects/triangle.rs

@@ -1,4 +1,4 @@
-use crate::objects::hit::Hit;
+use crate::objects::hit::{Hit, MinimalHit};
 use crate::objects::traits::Hittable;
 use crate::ray::Ray;
 use crate::{objects::materials::traits::Material, vec3::Vec3};
@@ -11,50 +11,66 @@ pub struct Triangle {
     p3: Vec3,
     material: Arc<dyn Material>,
     normal: Vec3,
+
+    // barycentric helpers
+    v0: Vec3,
+    v1: Vec3,
+    d00: f32,
+    d01: f32,
+    d11: f32,
+    denom: f32,
+    a4: f32,
 }
 
 impl Triangle {
     pub fn new(p1: Vec3, p2: Vec3, p3: Vec3, material: Arc<dyn Material>) -> Self {
+        // barycentric helpers cached to save computations
+        let v0 = p2 - p1;
+        let v1 = p3 - p1;
+        let d00 = v0.dot(&v0);
+        let d01 = v0.dot(&v1);
+        let d11 = v1.dot(&v1);
+        let a4 = (p3 - p1).cross(&(p2 - p1)).length();
+
         Self {
             p1,
             p2,
             p3,
             material,
             normal: (p2 - p1).cross(&(p3 - p1)).get_unit(),
+            v0,
+            v1,
+            d00,
+            d01,
+            d11,
+            denom: d00 * d11 - d01 * d01,
+            a4,
         }
     }
 
-    pub fn hit(
+    pub fn calculate_hit(&self, r: &Ray) -> Option<MinimalHit> {
-        p1: Vec3,
-        p2: Vec3,
-        p3: Vec3,
-        material: Arc<dyn Material>,
-        normal: Vec3,
-        r: &Ray,
-    ) -> Option<Hit> {
         // check if ray parallel to plane
-        let dot = normal.dot(r.dir());
+        let dot = self.normal.dot(r.dir());
         if dot == 0.0 {
             return None;
         }
 
-        let d = (-normal).dot(&p1);
+        let d = (-self.normal).dot(&self.p1);
         // hitpoint on plane
-        let t = -(normal.dot(&(r.origin() + d))) / dot;
+        let t = -(self.normal.dot(&(r.origin() + d))) / dot;
         // hits behind camera
         if t < 0. {
             return None;
         };
 
         let p = r.at(t);
-        let a4 = (p3 - p1).cross(&(p2 - p1)).length();
+        let a3 = (self.p3 - p).cross(&(self.p2 - p)).length();
-        let a3 = (p3 - p).cross(&(p2 - p)).length();
+        let a2 = (self.p3 - p).cross(&(self.p1 - p)).length();
-        let a2 = (p3 - p).cross(&(p1 - p)).length();
+        let a1 = (self.p2 - p).cross(&(self.p1 - p)).length();
-        let a1 = (p2 - p).cross(&(p1 - p)).length();
 
-        let diff = (a4 - a1 - a2 - a3).abs();
+        let diff = (self.a4 - a1 - a2 - a3).abs();
         if diff < 0.001 {
-            Some(Hit::new(t, p, normal, material, normal.dot(&r.dir()) < 0.))
+            Some(MinimalHit::new(t, p))
         } else {
             None
         }
@@ -74,13 +90,26 @@ impl Debug for Triangle {
 
 impl Hittable for Triangle {
     fn hit(&self, r: &Ray) -> Option<Hit> {
-        Triangle::hit(
+        let mh = self.calculate_hit(r)?;
-            self.p1,
+        let uvw = self.to_uv(mh.p());
-            self.p2,
+
-            self.p3,
+        Some(Hit::from_minimal(
-            self.material.clone(),
+            mh,
             self.normal,
-            r,
+            self.material.clone(),
-        )
+            self.normal.dot(r.dir()) < 0.,
+            *uvw.x(),
+            *uvw.y(),
+        ))
+    }
+
+    fn to_uv(&self, point: &Vec3) -> Vec3 {
+        let v2 = *point - self.p1;
+        let d20 = v2.dot(&self.v0);
+        let d21 = v2.dot(&self.v1);
+
+        let v = (self.d11 * d20 - self.d01 * d21) / self.denom;
+        let w = (self.d00 * d21 - self.d01 * d20) / self.denom;
+        Vec3::new(1. - v - w, v, w)
     }
 }

src/raytracer.rs

@@ -1,8 +1,8 @@
 use image::{ExtendedColorType, ImageEncoder, codecs::png::PngEncoder};
-use log::{error, info};
+use log::{error, info, trace};
 use rayon::iter::IntoParallelIterator;
 use rayon::prelude::*;
-use std::{fs::File, sync::Arc};
+use std::{fs::File, sync::Arc, time::Instant};
 
 use crate::{
     objects::{hit::Hit, traits::Hittable},
@@ -24,52 +24,55 @@ pub fn write_image(filename: &str, pixels: &[u8], width: u32, height: u32) {
 }
 
 pub fn render(scene: &mut Scene) {
-    let camera = &mut scene.camera;
+    scene.init();
-    camera.init(scene.image_width as f32, scene.image_height as f32);
 
     // TODO: currently splits per vertical line, but could be more granular (per chunk)
-    let mut pixels = vec![0 as u8; (scene.image_width * scene.image_height * 3) as usize];
+    let mut pixels = vec![0_u8; (scene.get_image_width() * scene.get_image_height() * 3) as usize];
     let scanlines: Vec<(usize, &mut [u8])> = pixels
-        .chunks_mut(scene.image_width as usize * 3)
+        .chunks_mut(scene.get_image_width() as usize * 3)
         .enumerate()
         .collect();
 
+    let now = Instant::now();
     scanlines.into_par_iter().for_each(|(i, chunk)| {
         render_chunk(chunk, scene, i as u32);
     });
+    info!(
+        "rendering took {}.{} seconds.",
+        now.elapsed().as_secs(),
+        now.elapsed().subsec_nanos()
+    );
 
     info!("Writing image file...");
     write_image(
-        &scene.filename,
+        &scene.get_filename(),
         &pixels,
-        scene.image_width,
+        scene.get_image_width() as u32,
-        scene.image_height,
+        scene.get_image_height() as u32,
     );
 }
 
 pub fn render_chunk(chunk: &mut [u8], scene: &Scene, y: u32) {
-    let camera = &scene.camera;
+    let camera = &scene.get_camera();
+    let aa_rate = &scene.get_camera().get_anti_alias_rate();
 
-    for i in 0..scene.image_width {
+    for i in 0..scene.get_image_width() {
-        let pixel_tl = camera.pixel00_loc + (i * camera.pixel_delta_u) + (y * camera.pixel_delta_v);
+        let pixel_tl = camera.get_pixel_tl(i, y);
-        // THOUGHT: the above seems more efficient (esp for larger aa rates) but can test for a
-        // get_ray_no_tl() function and compare performance.
 
         let mut pixel_colour = Colour::default();
-        for y in 1..(camera.anti_alias_rate + 1) {
+        for y in 1..(aa_rate + 1) {
-            for x in 1..(camera.anti_alias_rate + 1) {
+            for x in 1..(aa_rate + 1) {
                 let r = camera.get_ray(pixel_tl, x, y);
-                pixel_colour += ray_colour(&scene.objects, &r, scene.max_depth);
+                pixel_colour += ray_colour(&scene.get_objects(), &r, scene.get_max_depth());
             }
         }
 
-        let (r, g, b) =
+        let (r, g, b) = (pixel_colour / (aa_rate * aa_rate) as f32).output();
-            (pixel_colour / (camera.anti_alias_rate * camera.anti_alias_rate) as f32).output();
         chunk[(i * 3) as usize] = r;
         chunk[(i * 3) as usize + 1] = g;
         chunk[(i * 3) as usize + 2] = b;
     }
-    info!("Line {}\tfinished.", y);
+    trace!("Line {}\tfinished.", y);
 }
 
 pub fn ray_colour(hittables: &Vec<Arc<dyn Hittable>>, r: &Ray, depth: u32) -> Colour {

src/scenes/material_def.rs

@@ -2,7 +2,7 @@ use std::sync::Arc;
 
 use serde::Deserialize;
 
-use crate::objects::materials::{dielectric::Dielectric, lambertian::{Lambertian, Metal}, normal::Normal, traits::Material};
+use crate::objects::materials::{dielectric::Dielectric, lambertian::{Lambertian, Metal}, normal::Normal, texture::Texture, traits::Material};
 
 
 #[derive(Deserialize)]
@@ -12,6 +12,7 @@ pub(crate) enum MaterialDef {
     Metal(Metal),
     Dielectric(Dielectric),
     Normal(Normal),
+    Texture(RawTexture),
 }
 
 impl MaterialDef {
@@ -21,7 +22,13 @@ impl MaterialDef {
             MaterialDef::Metal(m) => Arc::new(m),
             MaterialDef::Dielectric(d) => Arc::new(d),
             MaterialDef::Normal(n) => Arc::new(n),
+            MaterialDef::Texture(t) => Arc::new(Texture::new(&t.source)), 
         }
     }
 }
 
+#[derive(Deserialize)]
+pub(crate) struct RawTexture {
+    pub source: String,
+}
+

src/scenes/scene.rs

@@ -1,23 +1,35 @@
 use std::sync::Arc;
 
+use rand::RngExt;
 use serde::Deserialize;
 
 use crate::{
     camera::Camera,
-    objects::{materials::traits::Material, traits::Hittable},
+    objects::{
+        materials::{
+            dielectric::Dielectric,
+            lambertian::{Lambertian, Metal},
+            traits::Material,
+        },
+        sphere::Sphere,
+        traits::Hittable,
+    },
     scenes::{hittable_def::HittableDef, material_def::MaterialDef, raw_camera::RawCamera},
+    vec3::Vec3,
 };
 
 #[derive(Debug)]
 pub struct Scene {
-    pub camera: Camera, // FIXME: should not be public
+    camera: Camera,
-    pub objects: Vec<Arc<dyn Hittable>>,
+    objects: Vec<Arc<dyn Hittable>>,
+
     // image
-    pub filename: String,
+    filename: String,
-    pub image_width: u32,
+    image_width: u32,
-    pub image_height: u32,
+    image_height: u32,
+
     // raytracing // TODO: think about organisation of these vars, also in Camera
-    pub max_depth: u32,
+    max_depth: u32,
 }
 
 impl Scene {
@@ -38,6 +50,129 @@ impl Scene {
             max_depth,
         }
     }
+
+    pub fn random() -> Self {
+        let ground = Lambertian::rgb(-2.5, 0.5, 0.5, 1.);
+        let mut world: Vec<Arc<dyn Hittable>> = vec![Arc::new(Sphere::xyz(
+            0.,
+            -1000.,
+            0.,
+            1000.,
+            Arc::new(ground),
+        ))];
+
+        let mut rng = rand::rng();
+        let point = Vec3::new(4., 0.2, 0.);
+        for a in -11..11 {
+            for b in -11..11 {
+                let mat = rng.random_range((0.)..1.);
+                let center = Vec3::new(
+                    a as f32 + 0.9 * rng.random_range((0.)..1.),
+                    0.2,
+                    b as f32 + 0.9 * rng.random_range((0.)..1.),
+                );
+
+                if (center - point).length() > 0.9 {
+                    if mat < 0.8 {
+                        // diffuse
+                        world.push(Arc::new(Sphere::new(
+                            center,
+                            0.2,
+                            Arc::new(Lambertian::new(Vec3::random() * Vec3::random(), 1.)),
+                        )));
+                    } else if mat < 0.95 {
+                        // metal
+                        world.push(Arc::new(Sphere::new(
+                            center,
+                            0.2,
+                            Arc::new(Metal::rgb(
+                                rng.random_range(0.5..1.),
+                                rng.random_range(0.5..1.),
+                                rng.random_range(0.5..1.),
+                                1.,
+                                rng.random_range((0.)..0.5),
+                            )),
+                        )));
+                    } else {
+                        // glass
+                        world.push(Arc::new(Sphere::new(
+                            center,
+                            0.2,
+                            Arc::new(Dielectric::new(1.5)),
+                        )));
+                    }
+                }
+            }
+        }
+
+        world.push(Arc::new(Sphere::xyz(
+            0.,
+            1.,
+            0.,
+            1.,
+            Arc::new(Dielectric::new(1.5)),
+        )));
+        world.push(Arc::new(Sphere::xyz(
+            -4.,
+            1.,
+            0.,
+            1.,
+            Arc::new(Lambertian::rgb(0.4, 0.2, 0.1, 1.)),
+        )));
+        world.push(Arc::new(Sphere::xyz(
+            4.,
+            1.,
+            0.,
+            1.,
+            Arc::new(Metal::rgb(0.7, 0.6, 0.5, 1., 0.)),
+        )));
+
+        let mut c = Camera::new();
+        c.set_fov(20.);
+        c.set_anti_alias_rate(2);
+        c.set_vup(Vec3::new(0., 1., 0.));
+        c.set_look_from(Vec3::new(13., 2., 3.));
+        c.set_look_at(Vec3::new(0., 0., 0.));
+        c.add_defocus_blur(0.6, 10.);
+
+        Self {
+            camera: c,
+            objects: world,
+            filename: "random.png".to_string(),
+            image_width: 1920,
+            image_height: 1080,
+            max_depth: 50,
+        }
+    }
+
+    pub fn get_camera(&self) -> &Camera {
+        &self.camera
+    }
+
+    pub fn get_image_width(&self) -> u32 {
+        self.image_width
+    }
+
+    pub fn get_image_height(&self) -> u32 {
+        self.image_height
+    }
+
+    pub fn get_objects(&self) -> &Vec<Arc<dyn Hittable>> {
+        &self.objects
+    }
+
+    pub fn get_max_depth(&self) -> u32 {
+        self.max_depth
+    }
+
+    pub fn get_filename(&self) -> &String {
+        &self.filename
+    }
+
+    pub fn init(&mut self) {
+        self.camera
+            .init(self.get_image_width(), self.get_image_height());
+    }
 }
 
 #[derive(Deserialize)]

src/vec3.rs

@@ -29,6 +29,14 @@ impl Vec3 {
         }
     }
 
+    pub fn from_u8(r: u8, b: u8, g: u8) -> Self {
+        Self {
+            x: r as f32 / 255.,
+            y: g as f32 / 255.,
+            z: b as f32 / 255.,
+        }
+    }
+
     pub fn random() -> Self {
         let mut rng = rand::rng();
         Self {
@@ -436,16 +444,20 @@ impl Div<Vec3> for Vec3 {
         }
     }
 }
+
+impl Div<u32> for Vec3 {
+    type Output = Self;
+
+    fn div(self, u: u32) -> Self::Output {
+        self / u as f32
+    }
+}
+
 impl Div<i32> for Vec3 {
     type Output = Self;
 
     fn div(self, i: i32) -> Self::Output {
-        let f: f32 = i as f32;
+        self / i as f32
-        Self {
-            x: self.x / f,
-            y: self.y / f,
-            z: self.z / f,
-        }
     }
 }