diff --git a/geometry/src/aabb.rs b/geometry/src/aabb.rs
index bb2328f1..d6d56e49 100644
--- a/geometry/src/aabb.rs
+++ b/geometry/src/aabb.rs
@@ -54,6 +54,7 @@ impl Aabb {
         8. * self.half_size.x * self.half_size.y * self.half_size.z
     }
 
+    #[must_use]
     pub fn translate(&self, delta: &Vector3<f32>) -> Aabb {
         Aabb {
             center: self.center + delta,
@@ -61,6 +62,7 @@ impl Aabb {
         }
     }
 
+    #[must_use]
     pub fn enlarge(&self, delta: &Vector3<f32>) -> Aabb {
         Aabb {
             center: self.center,
@@ -73,13 +75,11 @@ impl Aabb {
         let snd_half_axis = (self.max()[plane.axis] - plane.distance) / 2.;
         debug_assert!(
             fst_half_axis >= 0.0,
-            "fst_half_axis is negative {}",
-            fst_half_axis
+            "fst_half_axis is negative {fst_half_axis}",
         );
         debug_assert!(
             snd_half_axis >= 0.0,
-            "snd_half_axis is negative {}",
-            snd_half_axis
+            "snd_half_axis is negative {snd_half_axis}",
         );
 
         let mut fst_center = self.center;
diff --git a/geometry/src/algorithms.rs b/geometry/src/algorithms.rs
index ab4e6a3f..4bedd351 100644
--- a/geometry/src/algorithms.rs
+++ b/geometry/src/algorithms.rs
@@ -252,6 +252,10 @@ mod tests_intersect_triangle_ray {
 }
 
 pub fn intersect_triangle_aabb(triangle: &Triangle, aabb: &Aabb) -> bool {
+    const U0: Vector3<f32> = Vector3::new(1., 0., 0.);
+    const U1: Vector3<f32> = Vector3::new(0., 1., 0.);
+    const U2: Vector3<f32> = Vector3::new(0., 0., 1.);
+
     let v0 = triangle.v0 - aabb.center;
     let v1 = triangle.v1 - aabb.center;
     let v2 = triangle.v2 - aabb.center;
@@ -260,10 +264,6 @@ pub fn intersect_triangle_aabb(triangle: &Triangle, aabb: &Aabb) -> bool {
     let f1 = v2 - v1;
     let f2 = v0 - v2;
 
-    const U0: Vector3<f32> = Vector3::new(1., 0., 0.);
-    const U1: Vector3<f32> = Vector3::new(0., 1., 0.);
-    const U2: Vector3<f32> = Vector3::new(0., 0., 1.);
-
     let test_axis = |axis: Vector3<f32>| {
         let p0 = v0.dot(&axis);
         let p1 = v1.dot(&axis);
diff --git a/geometry/src/ray.rs b/geometry/src/ray.rs
index 5693186e..4bb40d47 100644
--- a/geometry/src/ray.rs
+++ b/geometry/src/ray.rs
@@ -14,6 +14,7 @@ impl Ray {
         }
     }
 
+    #[must_use]
     pub fn extend(&self, t: f32) -> Ray {
         Ray {
             origin: self.origin,
@@ -25,6 +26,7 @@ impl Ray {
         self.origin + t * self.direction
     }
 
+    #[must_use]
     pub fn reverse(&self) -> Ray {
         Ray {
             origin: self.origin + self.direction,
diff --git a/kdtree/src/build_median.rs b/kdtree/src/build_median.rs
index 5608fbd7..cd902d26 100644
--- a/kdtree/src/build_median.rs
+++ b/kdtree/src/build_median.rs
@@ -7,6 +7,8 @@ use geometry::{
     triangle::Triangle,
 };
 
+use crate::split::ClippedTriangle;
+
 use super::{
     build::{KdBox, KdSplit, KdTreeBuilder},
     split::{clip_triangle, split_and_partition},
@@ -47,7 +49,7 @@ impl KdTreeBuilder for MedianKdTreeBuilder {
             .collect::<Vec<_>>();
         let planes = clipped_triangles
             .iter()
-            .flat_map(|clipped| clipped.perfect_splits())
+            .flat_map(ClippedTriangle::perfect_splits)
             .filter_map(|s| {
                 (s.axis == axis && s.distance > min && s.distance < max).then_some(Aap {
                     axis: s.axis,
diff --git a/kdtree/src/build_sah.rs b/kdtree/src/build_sah.rs
index 33b22213..2a5fcce5 100644
--- a/kdtree/src/build_sah.rs
+++ b/kdtree/src/build_sah.rs
@@ -89,7 +89,7 @@ impl KdTreeBuilder for SahKdTreeBuilder {
             .collect::<Vec<_>>();
         let mut splits = clipped_triangles
             .iter()
-            .flat_map(|clipped| clipped.perfect_splits())
+            .flat_map(ClippedTriangle::perfect_splits)
             .collect::<Vec<_>>();
         splits.sort_unstable_by(PerfectSplit::total_cmp);
         splits.dedup();
diff --git a/kdtree/src/lib.rs b/kdtree/src/lib.rs
index 638df3a5..c82c49c0 100644
--- a/kdtree/src/lib.rs
+++ b/kdtree/src/lib.rs
@@ -47,7 +47,7 @@ impl KdNode {
 impl Display for KdNode {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
-            KdNode::Leaf(triangle_indices) => write!(f, "{:?}", triangle_indices),
+            KdNode::Leaf(triangle_indices) => write!(f, "{triangle_indices:?}"),
             KdNode::Node { plane, left, right } => {
                 write!(
                     f,
diff --git a/pathtracer-cli/src/main.rs b/pathtracer-cli/src/main.rs
index 007c10d1..7999da45 100644
--- a/pathtracer-cli/src/main.rs
+++ b/pathtracer-cli/src/main.rs
@@ -129,7 +129,7 @@ fn main() {
         .into_par_iter()
         .map(|i| worker_thread(i, &work, iterations_per_thread, &tx));
     let printer = std::thread::spawn(move || printer_thread(args.threads, args.iterations, rx));
-    let buffer = buffers.reduce_with(|a, b| a.add(b)).unwrap();
+    let buffer = buffers.reduce_with(|a, b| a.add(&b)).unwrap();
     tx.send(time::Duration::ZERO).unwrap();
     printer.join().unwrap();
 
diff --git a/src/image_buffer.rs b/src/image_buffer.rs
index 3690b7c1..5974bde9 100644
--- a/src/image_buffer.rs
+++ b/src/image_buffer.rs
@@ -2,12 +2,13 @@ use std::path::Path;
 
 pub struct ImageBuffer(image::ImageBuffer<image::Rgb<f32>, Vec<f32>>);
 
-fn gamma_correct(x: &f32) -> f32 {
+fn gamma_correct(x: f32) -> f32 {
     const GAMMA_POWER: f32 = 1.0 / 2.2;
     1.0f32.min(x.powf(GAMMA_POWER))
 }
 
 impl ImageBuffer {
+    #[must_use]
     pub fn new(width: u32, height: u32) -> Self {
         ImageBuffer(image::ImageBuffer::new(width, height))
     }
@@ -23,6 +24,7 @@ impl ImageBuffer {
         self.0.height()
     }
 
+    #[must_use]
     pub fn div(&self, value: f32) -> Self {
         ImageBuffer(
             image::ImageBuffer::from_vec(
@@ -34,7 +36,8 @@ impl ImageBuffer {
         )
     }
 
-    pub fn add(&self, rhs: Self) -> Self {
+    #[must_use]
+    pub fn add(&self, rhs: &Self) -> Self {
         ImageBuffer(
             image::ImageBuffer::from_vec(
                 self.0.width(),
@@ -49,11 +52,11 @@ impl ImageBuffer {
         )
     }
 
-    pub fn add_mut(&mut self, rhs: Self) {
+    pub fn add_mut(&mut self, rhs: &Self) {
         self.0
             .iter_mut()
             .zip(rhs.0.iter())
-            .for_each(|(a, b)| *a += *b)
+            .for_each(|(a, b)| *a += *b);
     }
 
     pub fn add_pixel_mut(&mut self, x: u32, y: u32, value: [f32; 3]) {
@@ -62,12 +65,13 @@ impl ImageBuffer {
         self.0[(x, y)][2] += value[2];
     }
 
+    #[must_use]
     pub fn gamma_correct(&self) -> Self {
         ImageBuffer(
             image::ImageBuffer::from_vec(
                 self.0.width(),
                 self.0.height(),
-                self.0.iter().map(gamma_correct).collect(),
+                self.0.iter().map(|x| gamma_correct(*x)).collect(),
             )
             .unwrap(),
         )
diff --git a/src/light.rs b/src/light.rs
index a0933f9c..e1625d15 100644
--- a/src/light.rs
+++ b/src/light.rs
@@ -1,7 +1,8 @@
-use crate::sampling::*;
 use nalgebra::Vector3;
 use rand::rngs::SmallRng;
 
+use crate::sampling::uniform_sample_unit_sphere;
+
 #[derive(Clone, Debug)]
 pub struct SphericalLight {
     pub center: Vector3<f32>,
diff --git a/src/material.rs b/src/material.rs
index 0de45d57..c6fcf324 100644
--- a/src/material.rs
+++ b/src/material.rs
@@ -1,7 +1,7 @@
-use crate::sampling::*;
 use nalgebra::{RealField, UnitVector3, Vector3};
-use rand::rngs::SmallRng;
-use rand::Rng;
+use rand::{rngs::SmallRng, Rng};
+
+use crate::sampling::cosine_sample_hemisphere;
 
 fn perpendicular(v: &Vector3<f32>) -> Vector3<f32> {
     if v.x.abs() < v.y.abs() {
diff --git a/src/pathtracer.rs b/src/pathtracer.rs
index 478a8b54..b281364f 100644
--- a/src/pathtracer.rs
+++ b/src/pathtracer.rs
@@ -1,8 +1,7 @@
-use crate::camera::*;
-use crate::image_buffer::ImageBuffer;
-use crate::raylogger::RayLoggerWithMeta;
-use crate::sampling::*;
-use crate::scene::*;
+use crate::{
+    camera::Pinhole, image_buffer::ImageBuffer, raylogger::RayLoggerWithMeta,
+    sampling::uniform_sample_unit_square, scene::Scene,
+};
 use geometry::ray::Ray;
 use nalgebra::{Vector2, Vector3};
 use rand::rngs::SmallRng;
@@ -15,7 +14,7 @@ fn trace_ray(
     _ray_logger: &mut RayLoggerWithMeta,
     max_bounces: u32,
     scene: &Scene,
-    ray: Ray,
+    ray: &Ray,
     accumulated_radiance: Vector3<f32>,
     accumulated_transport: Vector3<f32>,
     accumulated_bounces: u32,
@@ -25,11 +24,11 @@ fn trace_ray(
         return accumulated_radiance;
     }
 
-    let intersection = scene.intersect(&ray, 0.0, std::f32::MAX);
+    let intersection = scene.intersect(ray, 0.0, std::f32::MAX);
     if intersection.is_none() {
         //_ray_logger.log(&ray.extend(10.0)).unwrap();
         return accumulated_radiance
-            + accumulated_transport.component_mul(&environment_contribution(&ray));
+            + accumulated_transport.component_mul(&environment_contribution(ray));
     }
     let (triangle_index, intersection) = intersection.unwrap();
 
@@ -94,7 +93,7 @@ fn trace_ray(
         _ray_logger,
         max_bounces,
         scene,
-        next_ray,
+        &next_ray,
         accumulated_radiance,
         accumulated_transport,
         accumulated_bounces + 1,
@@ -121,7 +120,7 @@ pub fn render(
                 &mut logger,
                 max_bounces,
                 scene,
-                ray,
+                &ray,
                 Vector3::zeros(),
                 Vector3::new(1.0, 1.0, 1.0),
                 0,
diff --git a/src/raytracer.rs b/src/raytracer.rs
index cea41bda..ab0e5bbb 100644
--- a/src/raytracer.rs
+++ b/src/raytracer.rs
@@ -1,8 +1,7 @@
-use crate::camera::*;
-use crate::image_buffer::ImageBuffer;
-use crate::light::*;
-use crate::material::*;
-use crate::scene::*;
+use crate::{
+    camera::Pinhole, image_buffer::ImageBuffer, light::SphericalLight, material::Material,
+    scene::Scene,
+};
 use geometry::ray::Ray;
 use nalgebra::{UnitVector3, Vector2, Vector3};
 
diff --git a/src/scene.rs b/src/scene.rs
index d5fcd4b5..e73d2369 100644
--- a/src/scene.rs
+++ b/src/scene.rs
@@ -1,10 +1,18 @@
-use crate::{camera::*, light::*, material::*};
 use geometry::{algorithms::TriangleRayIntersection, ray::Ray, triangle::Triangle};
 use kdtree::{build::build_kdtree, build_sah::SahKdTreeBuilder, KdTree};
 use nalgebra::{UnitVector3, Vector2, Vector3};
 use std::{collections::BTreeMap, sync::Arc};
 use wavefront::{mtl, obj};
 
+use crate::{
+    camera::Camera,
+    light::SphericalLight,
+    material::{
+        BlendMaterial, DiffuseReflectiveMaterial, FresnelBlendMaterial, Material,
+        SpecularReflectiveMaterial, SpecularRefractiveMaterial,
+    },
+};
+
 #[derive(Clone, Debug, PartialEq)]
 pub struct TriangleNormals {
     pub n0: Vector3<f32>,
@@ -104,11 +112,11 @@ fn triangle_materials_from_obj_and_mtl(
     obj: &obj::Obj,
     mtl: &mtl::Mtl,
 ) -> Vec<Arc<dyn Material + Send + Sync>> {
-    let materials = BTreeMap::from_iter(
-        mtl.materials
-            .iter()
-            .map(|m| (m.name.as_str(), blend_from_mtl(m))),
-    );
+    let materials = mtl
+        .materials
+        .iter()
+        .map(|m| (m.name.as_str(), blend_from_mtl(m)))
+        .collect::<BTreeMap<_, _>>();
     obj.chunks
         .iter()
         .flat_map(|chunk| {
diff --git a/wavefront/src/mtl.rs b/wavefront/src/mtl.rs
index 0a18ba61..69d7e4f8 100644
--- a/wavefront/src/mtl.rs
+++ b/wavefront/src/mtl.rs
@@ -84,45 +84,45 @@ pub fn mtl(input: &str) -> Mtl {
         }
 
         if let Ok((_, _)) = tagged("newlight", rest, line) {
-            lights.push(Default::default())
+            lights.push(Light::default());
         } else if let Ok((_, x)) = tagged("lightposition", vec3, line) {
-            lights.last_mut().unwrap().position = x
+            lights.last_mut().unwrap().position = x;
         } else if let Ok((_, x)) = tagged("lightcolor", vec3, line) {
-            lights.last_mut().unwrap().color = x
+            lights.last_mut().unwrap().color = x;
         } else if let Ok((_, x)) = tagged("lightradius", float, line) {
-            lights.last_mut().unwrap().radius = x
+            lights.last_mut().unwrap().radius = x;
         } else if let Ok((_, x)) = tagged("lightintensity", float, line) {
-            lights.last_mut().unwrap().intensity = x
+            lights.last_mut().unwrap().intensity = x;
         } else if let Ok((_, _)) = tagged("newcamera", rest, line) {
-            cameras.push(Default::default())
+            cameras.push(Camera::default());
         } else if let Ok((_, x)) = tagged("cameraposition", vec3, line) {
-            cameras.last_mut().unwrap().position = x
+            cameras.last_mut().unwrap().position = x;
         } else if let Ok((_, x)) = tagged("cameratarget", vec3, line) {
-            cameras.last_mut().unwrap().target = x
+            cameras.last_mut().unwrap().target = x;
         } else if let Ok((_, x)) = tagged("cameraup", vec3, line) {
-            cameras.last_mut().unwrap().up = x
+            cameras.last_mut().unwrap().up = x;
         } else if let Ok((_, x)) = tagged("camerafov", float, line) {
-            cameras.last_mut().unwrap().fov = x
+            cameras.last_mut().unwrap().fov = x;
         } else if let Ok((_, name)) = tagged("newmtl", rest, line) {
             materials.push(Material::new(name.to_string()));
         } else if let Ok((_, x)) = tagged("kd", vec3, line) {
-            materials.last_mut().unwrap().diffuse_reflection = x
+            materials.last_mut().unwrap().diffuse_reflection = x;
         } else if let Ok((_, x)) = tagged("ks", vec3, line) {
-            materials.last_mut().unwrap().specular_reflection = x
+            materials.last_mut().unwrap().specular_reflection = x;
         } else if let Ok((_, x)) = tagged("reflat0deg", float, line) {
-            materials.last_mut().unwrap().reflection_0_degrees = x
+            materials.last_mut().unwrap().reflection_0_degrees = x;
         } else if let Ok((_, x)) = tagged("reflat90deg", float, line) {
-            materials.last_mut().unwrap().reflection_90_degrees = x
+            materials.last_mut().unwrap().reflection_90_degrees = x;
         } else if let Ok((_, x)) = tagged("indexofrefraction", float, line) {
-            materials.last_mut().unwrap().index_of_refraction = x
+            materials.last_mut().unwrap().index_of_refraction = x;
         } else if let Ok((_, x)) = tagged("transparency", float, line) {
-            materials.last_mut().unwrap().transparency = x
+            materials.last_mut().unwrap().transparency = x;
         } else if let Ok((_, _)) = tagged("specularroughness", float, line) {
             // TODO: not supported
         } else if let Ok((_, _)) = tagged("map_kd", rest, line) {
             // TODO: not supported
         } else {
-            panic!("Unexpected line: \"{}\"", line)
+            panic!("Unexpected line: \"{line}\"");
         }
     }
 
diff --git a/wavefront/src/obj.rs b/wavefront/src/obj.rs
index 79e129bf..4d783236 100644
--- a/wavefront/src/obj.rs
+++ b/wavefront/src/obj.rs
@@ -119,23 +119,23 @@ pub fn obj(input: &str) -> Obj {
         }
 
         if let Ok((_, x)) = tagged("mtllib", rest, line) {
-            mtl_lib = Path::new(x)
+            mtl_lib = Path::new(x);
         } else if let Ok((_, x)) = tagged("usemtl", rest, line) {
-            chunks.push(Chunk::new(x.to_string()))
+            chunks.push(Chunk::new(x.to_string()));
         } else if let Ok((_, x)) = tagged("v", vec3, line) {
-            vertices.push(x)
+            vertices.push(x);
         } else if let Ok((_, x)) = tagged("vn", vec3, line) {
-            normals.push(x)
+            normals.push(x);
         } else if let Ok((_, x)) = tagged("vt", vec2, line) {
-            texcoords.push(x)
+            texcoords.push(x);
         } else if let Ok((_, x)) = tagged("f", triangle, line) {
-            chunks.last_mut().unwrap().faces.push(x)
+            chunks.last_mut().unwrap().faces.push(x);
         } else if let Ok((_, _)) = tagged("o", rest, line) {
             // TODO: not supported
         } else if let Ok((_, _)) = tagged("s", rest, line) {
             // TODO: not supported
         } else {
-            panic!("Unexpected line: \"{}\"", line)
+            panic!("Unexpected line: \"{line}\"");
         }
     }