diff --git a/Cargo.lock b/Cargo.lock
index 1150ab5..a879c7a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1240,6 +1240,7 @@ dependencies = [
  "ops",
  "pretty_env_logger",
  "rand 0.10.1",
+ "rayon",
  "serde",
  "serde_json",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 96da94d..4e096d2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,11 +5,12 @@ edition = "2024"
 
 [dependencies]
 dotenv = "0.15.0"
-image = "0.25.10"
+image = {version = "0.25.10", features = ["png"]}
 is_close = "0.1.3"
 log = "0.4.29"
 ops = "0.6.0"
 pretty_env_logger = "0.5.0"
 rand = "0.10.1"
+rayon = "1.12.0"
 serde = {version = "1.0.228", features = ["derive"]}
 serde_json = "1.0.149"
diff --git a/scenes/failsMatBounds.json b/scenes/failsMatBounds.json
deleted file mode 100644
index b7d0a37..0000000
--- a/scenes/failsMatBounds.json
+++ /dev/null
@@ -1,22 +0,0 @@
-{
-  "camera": { 
-    "image_width": 1920,
-    "image_height": 1080,
-    "anti_alias_rate": 1,
-    "max_depth": 10,
-    "fov": 90.0,
-    "look_from": { "x": -10, "y": 5, "z": 10 },
-    "look_at": { "x": 0.0, "y": 0.0, "z": -1.0 }, 
-    "vup": { "x": 0.0, "y": 1.0, "z": 0.0 }
-  },
-  "materials": [
-    { "type": "metal", "albedo": { "x": 0.2, "y": 0.4, "z": 0.8 }, "prob": 1.0, "fuzz": 0.1 }
-
-  ],
-  "objects": [
-    { "type": "sphere", "center": { "x": 0, "y": 0.7, "z": -0.4 }, "radius": 0.2, "material": 1}
-  ]
-}
-
-
-
diff --git a/scenes/scene.json b/scenes/scene.json
index 8928587..39b0a36 100644
--- a/scenes/scene.json
+++ b/scenes/scene.json
@@ -1,12 +1,13 @@
 {
+  "filename": "output.png",
+  "image_width": 1920,
+  "image_height": 1080,
+  "max_depth": 50,
   "camera": { 
-    "image_width": 1920,
-    "image_height": 1080,
-    "anti_alias_rate": 2,
-    "max_depth": 50,
-    "fov": 90.0,
-    "look_from": [15, 4, 15],
-    "look_at": [0.0, 0.0, 0.0], 
+    "anti_alias_rate": 23,
+    "fov": 70.0,
+    "look_from": [-10, 4, 15],
+    "look_at": [-11.0, 0.0, 0.0], 
     "vup": [0.0, 1.0, 0.0],
     "defocus_angle": 0,
     "focus_dist": 15.68
@@ -28,7 +29,8 @@
     { "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": "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}}
  ]
 }
 
diff --git a/src/camera.rs b/src/camera.rs
index fdab07f..f965798 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -1,34 +1,23 @@
-use std::{f32::consts::PI, sync::Arc};
+use std::f32::consts::PI;
 
-use log::info;
-
-use crate::{
-    objects::{hit::Hit, traits::Hittable},
-    ray::Ray,
-    vec3::{Colour, Vec3},
-};
+use crate::{ray::Ray, vec3::Vec3};
 
 #[derive(Debug)]
 pub struct Camera {
-    // output
-    image_width: u32,
-    image_height: u32,
-
     // raytracing
-    anti_alias_rate: u32,
-    max_depth: u32,
-    pixel00_loc: Vec3,
-    pixel_delta_u: Vec3,
-    pixel_delta_v: Vec3,
+    pub anti_alias_rate: u32,
+    pub pixel00_loc: Vec3,
+    pub pixel_delta_u: Vec3,
+    pub pixel_delta_v: Vec3,
 
     // camera
     dirty: bool,
-    fov: f32,
-    look_from: Vec3,
-    look_at: Vec3,
+    pub fov: f32,
+    pub look_from: Vec3,
+    pub look_at: Vec3,
     vup: Vec3,
-    defocus_angle: f32,
-    focus_dist: f32,
+    pub defocus_angle: f32,
+    pub focus_dist: f32,
 
     // camera helpers
     u: Vec3,
@@ -44,12 +33,9 @@ fn deg_to_rad(deg: f32) -> f32 {
 }
 
 impl Camera {
-    pub fn new(image_width: u32, image_height: u32) -> Self {
+    pub fn new() -> Self {
         Self {
-            image_width,
-            image_height,
             anti_alias_rate: 1,
-            max_depth: 10,
             dirty: true,
             fov: 60.,
             pixel00_loc: Vec3::default(),
@@ -69,10 +55,7 @@ impl Camera {
     }
 
     pub fn new_full(
-        image_width: u32,
-        image_height: u32,
         anti_alias_rate: u32,
-        max_depth: u32,
         fov: f32,
         look_from: Vec3,
         look_at: Vec3,
@@ -81,10 +64,7 @@ impl Camera {
         focus_dist: f32,
     ) -> Self {
         Self {
-            image_width,
-            image_height,
             anti_alias_rate,
-            max_depth,
             pixel00_loc: Vec3::default(),
             pixel_delta_u: Vec3::default(),
             pixel_delta_v: Vec3::default(),
@@ -103,7 +83,11 @@ impl Camera {
         }
     }
 
-    fn init(&mut self) {
+    pub fn init(&mut self, w: f32, hi: f32) {
+        if !self.dirty {
+            return;
+        }
+
         // camera
         let theta = deg_to_rad(self.fov);
         let h = (theta / 2.).tan();
@@ -113,13 +97,13 @@ impl Camera {
 
         // viewport
         let viewport_height = 2. * h * self.focus_dist;
-        let viewport_width = viewport_height * (self.image_width as f32 / self.image_height as f32);
+        let viewport_width = viewport_height * (w / hi);
         let viewport_u = viewport_width * self.u;
         let viewport_v = viewport_height * -self.v;
 
         // variables
-        self.pixel_delta_u = viewport_u / self.image_width as f32;
-        self.pixel_delta_v = viewport_v / self.image_height as f32;
+        self.pixel_delta_u = viewport_u / w;
+        self.pixel_delta_v = viewport_v / hi;
         self.pixel00_loc =
             self.look_from - (self.focus_dist * self.w) - viewport_u / 2. - viewport_v / 2.;
         self.dirty = false;
@@ -131,6 +115,19 @@ impl Camera {
         }
     }
 
+    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)
+            + (y * self.pixel_delta_v / (self.anti_alias_rate + 1) as f32);
+        let ray_orig = if self.defocus_angle > 0. {
+            self.defocus_disk_sample()
+        } else {
+            self.look_from
+        };
+        let ray_dir = pixel_loc - ray_orig;
+        Ray::new(ray_orig, ray_dir)
+    }
+
     pub fn set_fov(&mut self, fov: f32) {
         if self.fov != fov {
             self.fov = fov;
@@ -138,13 +135,6 @@ impl Camera {
         }
     }
 
-    pub fn set_max_depth(&mut self, depth: u32) {
-        if self.max_depth != depth {
-            self.max_depth = depth;
-            self.dirty = true;
-        }
-    }
-
     pub fn set_anti_alias_rate(&mut self, rate: u32) {
         if self.anti_alias_rate != rate {
             self.anti_alias_rate = rate;
@@ -181,72 +171,8 @@ impl Camera {
         }
     }
 
-    fn defocus_disk_sample(&self) -> Vec3 {
+    pub fn defocus_disk_sample(&self) -> Vec3 {
         let p = Vec3::random_in_unit_disk();
         self.look_from + (p.x() * self.defocus_disk_u) + (p.y() * self.defocus_disk_v)
     }
-
-    pub fn render(&mut self, hittables: &Vec<Arc<dyn Hittable>>) {
-        if self.dirty {
-            self.init()
-        }
-
-        let mut imgbuf = image::ImageBuffer::new(self.image_width, self.image_height);
-
-        // render
-        for j in 0..self.image_height {
-            info!("{}\tScanlines remaining.", (self.image_height - j));
-            for i in 0..self.image_width {
-                let pixel_tl =
-                    self.pixel00_loc + (i * self.pixel_delta_u) + (j * self.pixel_delta_v);
-
-                let mut pixel_colour = Colour::default();
-                for y in 1..(self.anti_alias_rate + 1) {
-                    for x in 1..(self.anti_alias_rate + 1) {
-                        let pixel_loc = pixel_tl
-                            + (x * self.pixel_delta_u / (self.anti_alias_rate + 1) as f32)
-                            + (y * self.pixel_delta_v / (self.anti_alias_rate + 1) as f32);
-                        let ray_orig = if self.defocus_angle > 0. {
-                            self.defocus_disk_sample()
-                        } else {
-                            self.look_from
-                        };
-                        let ray_dir = pixel_loc - ray_orig;
-                        let r = Ray::new(ray_orig, ray_dir);
-                        pixel_colour += self.ray_colour(hittables, &r, self.max_depth);
-                    }
-                }
-
-                let pixel = imgbuf.get_pixel_mut(i, j);
-                *pixel =
-                    (pixel_colour / (self.anti_alias_rate * self.anti_alias_rate) as f32).output();
-            }
-        }
-
-        info!("Writing image file...");
-        imgbuf.save("output.png").unwrap();
-    }
-
-    fn ray_colour(&self, hittables: &Vec<Arc<dyn Hittable>>, r: &Ray, depth: u32) -> Colour {
-        if depth == 0 {
-            return Colour::default();
-        }
-
-        let closest = Hit::hit_list(hittables, r);
-        if let Some(hit) = closest {
-            if let Some((scattered, att)) = hit.mat().scatter(&hit, r) {
-                if let Some(ray) = scattered {
-                    return att * self.ray_colour(hittables, &ray, depth - 1);
-                }
-                return att;
-            }
-            return Colour::default();
-        }
-
-        // background
-        let unit_dir = r.dir().get_unit();
-        let a = 0.5 * (unit_dir.y() + 1.);
-
-        (1.0 - a) * Colour::new(1., 1., 1.) + a * Colour::new(0.5, 0.7, 1.0)
-    }
 }
diff --git a/src/main.rs b/src/main.rs
index dc739fe..f11924b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@
 mod camera;
 mod objects;
 mod ray;
+mod raytracer;
 mod scenes;
 mod vec3;
 
@@ -15,6 +16,7 @@ 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;
@@ -29,7 +31,7 @@ fn main() {
     let json_file = "./scenes/scene.json";
     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();
-    scene.render();
+    render(&mut scene);
     return;
 
     // random spheres code; thought: make this available as cli flag?
@@ -108,14 +110,14 @@ fn main() {
         Arc::new(Metal::rgb(0.7, 0.6, 0.5, 1., 0.)),
     )));
 
-    let mut c = Camera::new(1920, 1080);
+    let mut c = Camera::new();
     c.set_fov(20.);
     c.set_anti_alias_rate(23);
-    c.set_max_depth(50);
     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.);
 
-    c.render(&world);
+    let mut s = Scene::new(c, world, "output.png".to_string(), 1920, 1080, 50);
+    render(&mut s);
 }
diff --git a/src/objects.rs b/src/objects.rs
index 40f7466..b90ac27 100644
--- a/src/objects.rs
+++ b/src/objects.rs
@@ -1,7 +1,10 @@
+pub mod circle;
+pub mod cube;
+pub mod cylinder;
 pub mod hit;
 pub mod materials;
-pub mod sphere;
-pub mod triangle;
+pub mod mesh;
 pub mod quad;
-pub mod cube;
+pub mod sphere;
 pub mod traits;
+pub mod triangle;
diff --git a/src/objects/circle.rs b/src/objects/circle.rs
new file mode 100644
index 0000000..ee545fc
--- /dev/null
+++ b/src/objects/circle.rs
@@ -0,0 +1,52 @@
+use std::sync::Arc;
+
+use crate::{
+    objects::{materials::traits::Material, traits::Hittable},
+    ray::Ray,
+    vec3::Vec3,
+};
+
+use super::hit::Hit;
+
+#[derive(Debug)]
+pub struct Circle {
+    radius: f32,
+    center: Vec3,
+    normal: Vec3,
+    material: Arc<dyn Material>,
+}
+
+impl Circle {
+    pub fn new(radius: f32, center: Vec3, normal: Vec3, material: Arc<dyn Material>) -> Self {
+        Self {
+            radius,
+            center,
+            normal: normal.get_unit(),
+            material,
+        }
+    }
+}
+
+impl Hittable for Circle {
+    fn hit(&self, r: &Ray) -> Option<Hit> {
+        // check if ray parallel to plane
+        let dot = self.normal.dot(r.dir());
+        if dot == 0.0 {
+            return None;
+        }
+
+        // hitpoint on plane
+        let t = self.normal.dot(&(self.center - r.origin())) / dot;
+
+        // hits behind camera
+        if t < 0. {
+            return None;
+        };
+
+        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.)); 
+        }
+        None
+    }
+}
diff --git a/src/objects/cube.rs b/src/objects/cube.rs
index a2adb70..04e3e5b 100644
--- a/src/objects/cube.rs
+++ b/src/objects/cube.rs
@@ -41,9 +41,4 @@ impl Hittable for Cube {
     fn hit(&self, r: &Ray) -> Option<Hit> {
         Hit::hit_list(&self.faces, r)
     }
-
-    fn normal_at(&self, _p: &Vec3) -> Vec3 {
-        // TODO: normal calc for cube
-        todo!()
-    }
 }
diff --git a/src/objects/cylinder.rs b/src/objects/cylinder.rs
new file mode 100644
index 0000000..78d052d
--- /dev/null
+++ b/src/objects/cylinder.rs
@@ -0,0 +1,26 @@
+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!()
+    }
+}
diff --git a/src/objects/materials/dielectric.rs b/src/objects/materials/dielectric.rs
index ff6c1d7..bb1dad3 100644
--- a/src/objects/materials/dielectric.rs
+++ b/src/objects/materials/dielectric.rs
@@ -16,9 +16,7 @@ pub struct Dielectric {
 
 impl Dielectric {
     pub fn new(refraction_index: f32) -> Self {
-        Self {
-            refraction_index,
-        }
+        Self { refraction_index }
     }
 
     fn reflectance(cos: f32, refraction_index: f32) -> f32 {
@@ -46,7 +44,8 @@ impl Material for Dielectric {
         let cannot_refract = ri * sin_theta > 1.;
 
         let mut rng = rand::rng();
-        let dir = if cannot_refract || Dielectric::reflectance(cos_theta, ri) > rng.random::<f32>() {
+        let dir = if cannot_refract || Dielectric::reflectance(cos_theta, ri) > rng.random::<f32>()
+        {
             unit.reflect(hit.n())
         } else {
             unit.refract(hit.n(), ri)
diff --git a/src/objects/materials/lambertian.rs b/src/objects/materials/lambertian.rs
index 8420bc1..bfbba05 100644
--- a/src/objects/materials/lambertian.rs
+++ b/src/objects/materials/lambertian.rs
@@ -15,10 +15,7 @@ pub struct Lambertian {
 
 impl Lambertian {
     pub fn new(albedo: Colour, prob: f32) -> Self {
-        Self {
-            albedo,
-            prob,
-        }
+        Self { albedo, prob }
     }
 
     pub fn rgb(r: f32, g: f32, b: f32, prob: f32) -> Self {
@@ -53,11 +50,7 @@ pub struct Metal {
 
 impl Metal {
     pub fn new(albedo: Colour, prob: f32, fuzz: f32) -> Self {
-        Self {
-            albedo,
-            prob,
-            fuzz,
-        }
+        Self { albedo, prob, fuzz }
     }
 
     pub fn rgb(r: f32, g: f32, b: f32, prob: f32, fuzz: f32) -> Self {
diff --git a/src/objects/mesh.rs b/src/objects/mesh.rs
new file mode 100644
index 0000000..e69de29
diff --git a/src/objects/quad.rs b/src/objects/quad.rs
index db57ee5..5d3a3ea 100644
--- a/src/objects/quad.rs
+++ b/src/objects/quad.rs
@@ -69,9 +69,4 @@ impl Hittable for Quad {
             r,
         )
     }
-
-    fn normal_at(&self, _p: &Vec3) -> Vec3 {
-        // FIXME: might cause ownership issues
-        self.normal
-    }
 }
diff --git a/src/objects/sphere.rs b/src/objects/sphere.rs
index be6fb80..943e54e 100644
--- a/src/objects/sphere.rs
+++ b/src/objects/sphere.rs
@@ -2,12 +2,11 @@ use core::f32::math::sqrt;
 use std::fmt::{self, Debug};
 use std::sync::Arc;
 
-
+use crate::Vec3;
 use crate::objects::hit::Hit;
 use crate::objects::materials::traits::Material;
 use crate::objects::traits::Hittable;
 use crate::ray::Ray;
-use crate::Vec3;
 
 pub struct Sphere {
     center: Vec3,
@@ -63,14 +62,10 @@ impl Hittable for Sphere {
             Some(Hit::new(
                 t,
                 p,
-                self.normal_at(&p),
+                (p - self.center).get_unit(),
                 self.material.clone(),
                 out_n.dot(r.dir()) < 0.,
             ))
         }
     }
-
-    fn normal_at(&self, p: &Vec3) -> Vec3 {
-        (*p - self.center).get_unit()
-    }
 }
diff --git a/src/objects/traits.rs b/src/objects/traits.rs
index bfc1c4e..2a33df5 100644
--- a/src/objects/traits.rs
+++ b/src/objects/traits.rs
@@ -1,10 +1,8 @@
 use std::fmt::Debug;
 
-use crate::objects::hit::Hit;
 use crate::Ray;
-use crate::Vec3;
+use crate::objects::hit::Hit;
 
 pub trait Hittable: Debug + Send + Sync {
     fn hit(&self, r: &Ray) -> Option<Hit>;
-    fn normal_at(&self, p: &Vec3) -> Vec3;
 }
diff --git a/src/objects/triangle.rs b/src/objects/triangle.rs
index 051d212..c0b1f64 100644
--- a/src/objects/triangle.rs
+++ b/src/objects/triangle.rs
@@ -54,7 +54,7 @@ impl Triangle {
 
         let diff = (a4 - a1 - a2 - a3).abs();
         if diff < 0.001 {
-            Some(Hit::new(t, p, normal, material, normal.dot(&-r.dir()) > 0.))
+            Some(Hit::new(t, p, normal, material, normal.dot(&r.dir()) < 0.))
         } else {
             None
         }
@@ -83,9 +83,4 @@ impl Hittable for Triangle {
             r,
         )
     }
-
-    fn normal_at(&self, _p: &Vec3) -> Vec3 {
-        // FIXME: might cause ownership issues
-        self.normal
-    }
 }
diff --git a/src/ray.rs b/src/ray.rs
index 6f651d4..bf65407 100644
--- a/src/ray.rs
+++ b/src/ray.rs
@@ -7,10 +7,7 @@ pub struct Ray {
 
 impl Ray {
     pub fn new(origin: Vec3, dir: Vec3) -> Self {
-        Self {
-            origin,
-            dir,
-        }
+        Self { origin, dir }
     }
 
     pub fn at(&self, t: f32) -> Vec3 {
diff --git a/src/raytracer.rs b/src/raytracer.rs
new file mode 100644
index 0000000..b2b4167
--- /dev/null
+++ b/src/raytracer.rs
@@ -0,0 +1,96 @@
+use image::{ExtendedColorType, ImageEncoder, codecs::png::PngEncoder};
+use log::{error, info};
+use rayon::iter::IntoParallelIterator;
+use rayon::prelude::*;
+use std::{fs::File, sync::Arc};
+
+use crate::{
+    objects::{hit::Hit, traits::Hittable},
+    ray::Ray,
+    scenes::scene::Scene,
+    vec3::Colour,
+};
+
+pub fn write_image(filename: &str, pixels: &[u8], width: u32, height: u32) {
+    match File::create(filename) {
+        Ok(out) => {
+            let enc = PngEncoder::new(out);
+            if let Err(e) = enc.write_image(pixels, width, height, ExtendedColorType::Rgb8) {
+                error!("Failed writing image: {}", e);
+            }
+        }
+        Err(e) => error!("Failed to create image file: {} ", e),
+    }
+}
+
+pub fn render(scene: &mut Scene) {
+    let camera = &mut scene.camera;
+    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 scanlines: Vec<(usize, &mut [u8])> = pixels
+        .chunks_mut(scene.image_width as usize * 3)
+        .enumerate()
+        .collect();
+
+    scanlines.into_par_iter().for_each(|(i, chunk)| {
+        render_chunk(chunk, scene, i as u32);
+    });
+
+    info!("Writing image file...");
+    write_image(
+        &scene.filename,
+        &pixels,
+        scene.image_width,
+        scene.image_height,
+    );
+}
+
+pub fn render_chunk(chunk: &mut [u8], scene: &Scene, y: u32) {
+    let camera = &scene.camera;
+
+    for i in 0..scene.image_width {
+        let pixel_tl = camera.pixel00_loc + (i * camera.pixel_delta_u) + (y * camera.pixel_delta_v);
+        // 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 x in 1..(camera.anti_alias_rate + 1) {
+                let r = camera.get_ray(pixel_tl, x, y);
+                pixel_colour += ray_colour(&scene.objects, &r, scene.max_depth);
+            }
+        }
+
+        let (r, g, b) =
+            (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 {} finished.", y);
+}
+
+pub fn ray_colour(hittables: &Vec<Arc<dyn Hittable>>, r: &Ray, depth: u32) -> Colour {
+    if depth == 0 {
+        return Colour::default();
+    }
+
+    let closest = Hit::hit_list(hittables, r);
+    if let Some(hit) = closest {
+        if let Some((scattered, att)) = hit.mat().scatter(&hit, r) {
+            if let Some(ray) = scattered {
+                return att * ray_colour(hittables, &ray, depth - 1);
+            }
+            return att;
+        }
+        return Colour::default();
+    }
+
+    // background
+    let unit_dir = r.dir().get_unit();
+    let a = 0.5 * (unit_dir.y() + 1.);
+
+    (1.0 - a) * Colour::new(1., 1., 1.) + a * Colour::new(0.5, 0.7, 1.0)
+}
diff --git a/src/scenes/hittable_def.rs b/src/scenes/hittable_def.rs
index ff547c1..dd6f3af 100644
--- a/src/scenes/hittable_def.rs
+++ b/src/scenes/hittable_def.rs
@@ -5,8 +5,8 @@ use serde::Deserialize;
 
 use crate::{
     objects::{
-        cube::Cube, materials::traits::Material, quad::Quad, sphere::Sphere, traits::Hittable,
-        triangle::Triangle,
+        circle::Circle, cube::Cube, materials::traits::Material, quad::Quad, sphere::Sphere,
+        traits::Hittable, triangle::Triangle,
     },
     scenes::material_def::MaterialDef,
     vec3::Vec3,
@@ -19,11 +19,11 @@ pub(crate) enum HittableDef {
     Triangle(RawTriangle),
     Quad(RawQuad),
     Cube(RawCube),
+    Circle(RawCircle),
 }
 
 impl HittableDef {
     pub(crate) fn into_arc(self, materials: &Vec<Arc<dyn Material>>) -> Option<Arc<dyn Hittable>> {
-        // THOUGHT: i think this can be done better; in the map/filter call in scnene.deserialize?
         match self {
             HittableDef::Sphere(s) => {
                 let material = s.material.into_arc(materials);
@@ -55,6 +55,13 @@ impl HittableDef {
                     None => None,
                 }
             }
+            HittableDef::Circle(c) => {
+                let material = c.material.into_arc(materials);
+                match material {
+                    Some(m) => Some(Arc::new(Circle::new(c.radius, c.center, c.normal, m))),
+                    None => None,
+                }
+            }
         }
     }
 }
@@ -96,6 +103,14 @@ pub(crate) struct RawCube {
     pub material: RawMaterial,
 }
 
+#[derive(Deserialize)]
+pub(crate) struct RawCircle {
+    radius: f32,
+    center: Vec3,
+    normal: Vec3,
+    material: RawMaterial,
+}
+
 #[derive(Deserialize)]
 #[serde(untagged)]
 pub(crate) enum RawMaterial {
diff --git a/src/scenes/raw_camera.rs b/src/scenes/raw_camera.rs
index c8b2e98..c8a4af9 100644
--- a/src/scenes/raw_camera.rs
+++ b/src/scenes/raw_camera.rs
@@ -4,15 +4,9 @@ use crate::{camera::Camera, vec3::Vec3};
 
 #[derive(Deserialize)]
 pub struct RawCamera {
-    // output
-    image_width: u32,
-    image_height: u32,
-
     // raytracing
     #[serde(default)]
     anti_alias_rate: u32,
-    #[serde(default)]
-    max_depth: u32,
 
     // camera
     #[serde(default)]
@@ -32,10 +26,7 @@ pub struct RawCamera {
 impl Default for RawCamera {
     fn default() -> Self {
         Self {
-            image_width: 400,
-            image_height: 300,
             anti_alias_rate: 1,
-            max_depth: 10,
             fov: 70.,
             look_from: Vec3::new(0., 0., 0.),
             look_at: Vec3::new(0., 0., -1.),
@@ -49,10 +40,7 @@ impl Default for RawCamera {
 impl From<RawCamera> for Camera {
     fn from(raw: RawCamera) -> Self {
         Camera::new_full(
-            raw.image_width,
-            raw.image_height,
             raw.anti_alias_rate,
-            raw.max_depth,
             raw.fov,
             raw.look_from,
             raw.look_at,
diff --git a/src/scenes/scene.rs b/src/scenes/scene.rs
index 458a29c..527966a 100644
--- a/src/scenes/scene.rs
+++ b/src/scenes/scene.rs
@@ -10,14 +10,33 @@ use crate::{
 
 #[derive(Debug)]
 pub struct Scene {
-    pub camera: Camera,
-    pub _materials: Vec<Arc<dyn Material>>,
+    pub camera: Camera, // FIXME: should not be public
     pub objects: Vec<Arc<dyn Hittable>>,
+    // image
+    pub filename: String,
+    pub image_width: u32,
+    pub image_height: u32,
+    // raytracing // TODO: think about organisation of these vars, also in Camera
+    pub max_depth: u32,
 }
 
 impl Scene {
-    pub fn render(&mut self) {
-        self.camera.render(&self.objects);
+    pub fn new(
+        camera: Camera,
+        objects: Vec<Arc<dyn Hittable>>,
+        filename: String,
+        image_width: u32,
+        image_height: u32,
+        max_depth: u32,
+    ) -> Self {
+        Self {
+            camera,
+            objects,
+            filename,
+            image_width,
+            image_height,
+            max_depth,
+        }
     }
 }
 
@@ -26,6 +45,10 @@ struct SceneDef {
     pub camera: RawCamera,
     pub materials: Vec<MaterialDef>,
     pub objects: Vec<HittableDef>,
+    pub filename: String,
+    pub image_width: u32,
+    pub image_height: u32,
+    pub max_depth: u32,
 }
 
 impl<'de> Deserialize<'de> for Scene {
@@ -46,8 +69,11 @@ impl<'de> Deserialize<'de> for Scene {
             .collect();
         Ok(Self {
             camera: Camera::from(conc.camera),
-            _materials: mats,
             objects: objs,
+            filename: conc.filename,
+            image_width: conc.image_width,
+            image_height: conc.image_height,
+            max_depth: conc.max_depth,
         })
     }
 }
diff --git a/src/vec3.rs b/src/vec3.rs
index 582988a..8dcba26 100644
--- a/src/vec3.rs
+++ b/src/vec3.rs
@@ -122,7 +122,7 @@ impl Vec3 {
         r_out_perp + r_out_parr
     }
 
-    pub fn output(self) -> image::Rgb<u8> {
+    pub fn output(self) -> (u8, u8, u8) {
         // gamma correction
         let r = if self.x > 0. {
             sqrt(self.x).clamp(0., 1.)
@@ -144,7 +144,7 @@ impl Vec3 {
         let ig = (255.599 * g) as u8;
         let ib = (255.599 * b) as u8;
 
-        image::Rgb([ir, ig, ib])
+        (ir, ig, ib)
     }
 
     pub fn clone(&self) -> Self {