diff --git a/simul/.vscode/launch.json b/simul/.vscode/launch.json
new file mode 100644
index 0000000..5ddde67
--- /dev/null
+++ b/simul/.vscode/launch.json
@@ -0,0 +1,31 @@
+{
+    // Use IntelliSense to learn about possible attributes.
+    // Hover to view descriptions of existing attributes.
+    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "Debug executable 'simul'",
+            "type": "lldb",
+            "request": "launch",
+            "cargo": {
+                "args": [
+                    "run",
+                    "--bin=simul"
+                ]
+            },
+            "args": []
+        },
+        {
+            "name": "Debug unit tests in executable 'simul'",
+            "type": "lldb",
+            "request": "launch",
+            "cargo": {
+                "args": [
+                    "test",
+                    "--bin=simul"
+                ]
+            }
+        }
+    ]
+}
\ No newline at end of file
diff --git a/simul/Cargo.lock b/simul/Cargo.lock
index 017a1b2..bd24979 100644
--- a/simul/Cargo.lock
+++ b/simul/Cargo.lock
@@ -2,6 +2,12 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "autocfg"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
+
 [[package]]
 name = "bitflags"
 version = "2.11.0"
@@ -20,6 +26,43 @@ version = "0.2.184"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48f5d2a454e16a5ea0f4ced81bd44e4cfc7bd3a507b61887c99fd3538b28e4af"
 
+[[package]]
+name = "num-traits"
+version = "0.2.19"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "071dfc062690e90b734c0b2273ce72ad0ffa95f0c74596bc250dcfd960262841"
+dependencies = [
+ "autocfg",
+]
+
+[[package]]
+name = "obj-rs"
+version = "0.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8247fd8f66340ad9c969f96e63a80a2f74b04e5403d92584b75e046006f4c7e1"
+dependencies = [
+ "num-traits",
+ "serde",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.106"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8fd00f0bb2e90d81d1044c2b32617f68fcb9fa3bb7640c23e9c748e53fb30934"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.45"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41f2619966050689382d2b44f664f4bc593e129785a36d6ee376ddf37259b924"
+dependencies = [
+ "proc-macro2",
+]
+
 [[package]]
 name = "sdl3"
 version = "0.17.3"
@@ -58,9 +101,57 @@ dependencies = [
  "sdl3-sys",
 ]
 
+[[package]]
+name = "serde"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9a8e94ea7f378bd32cbbd37198a4a91436180c5bb472411e48b5ec2e2124ae9e"
+dependencies = [
+ "serde_core",
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_core"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "41d385c7d4ca58e59fc732af25c3983b67ac852c1a25000afe1175de458b67ad"
+dependencies = [
+ "serde_derive",
+]
+
+[[package]]
+name = "serde_derive"
+version = "1.0.228"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d540f220d3187173da220f885ab66608367b6574e925011a9353e4badda91d79"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "simul"
 version = "0.1.0"
 dependencies = [
+ "obj-rs",
  "sdl3",
 ]
+
+[[package]]
+name = "syn"
+version = "2.0.117"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e665b8803e7b1d2a727f4023456bbbbe74da67099c585258af0ad9c5013b9b99"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
diff --git a/simul/Cargo.toml b/simul/Cargo.toml
index 5666a20..b082c1a 100644
--- a/simul/Cargo.toml
+++ b/simul/Cargo.toml
@@ -4,4 +4,5 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+obj-rs = "0.7.4"
 sdl3 = { version = "0.17.3", features = ["ttf", "image"] }
diff --git a/simul/assets/cube.mtl b/simul/assets/cube.mtl
new file mode 100644
index 0000000..31c5ac7
--- /dev/null
+++ b/simul/assets/cube.mtl
@@ -0,0 +1,12 @@
+# Blender 5.1.0 MTL File: 'None'
+# www.blender.org
+
+newmtl Material
+Ns 250.000000
+Ka 1.000000 1.000000 1.000000
+Kd 0.800000 0.800000 0.800000
+Ks 0.500000 0.500000 0.500000
+Ke 0.000000 0.000000 0.000000
+Ni 1.500000
+d 1.000000
+illum 2
diff --git a/simul/assets/cube.obj b/simul/assets/cube.obj
new file mode 100644
index 0000000..b9b58a5
--- /dev/null
+++ b/simul/assets/cube.obj
@@ -0,0 +1,46 @@
+# Blender 5.1.0
+# www.blender.org
+mtllib cube.mtl
+o Cube
+v 1.000000 1.000000 -1.000000
+v 1.000000 -1.000000 -1.000000
+v 1.000000 1.000000 1.000000
+v 1.000000 -1.000000 1.000000
+v -1.000000 1.000000 -1.000000
+v -1.000000 -1.000000 -1.000000
+v -1.000000 1.000000 1.000000
+v -1.000000 -1.000000 1.000000
+vn -0.0000 1.0000 -0.0000
+vn -0.0000 -0.0000 1.0000
+vn -1.0000 -0.0000 -0.0000
+vn -0.0000 -1.0000 -0.0000
+vn 1.0000 -0.0000 -0.0000
+vn -0.0000 -0.0000 -1.0000
+vt 0.875000 0.500000
+vt 0.625000 0.750000
+vt 0.625000 0.500000
+vt 0.375000 1.000000
+vt 0.375000 0.750000
+vt 0.625000 0.000000
+vt 0.375000 0.250000
+vt 0.375000 0.000000
+vt 0.375000 0.500000
+vt 0.125000 0.750000
+vt 0.125000 0.500000
+vt 0.625000 0.250000
+vt 0.875000 0.750000
+vt 0.625000 1.000000
+s 0
+usemtl Material
+f 5/1/1 3/2/1 1/3/1
+f 3/2/2 8/4/2 4/5/2
+f 7/6/3 6/7/3 8/8/3
+f 2/9/4 8/10/4 6/11/4
+f 1/3/5 4/5/5 2/9/5
+f 5/12/6 2/9/6 6/7/6
+f 5/1/1 7/13/1 3/2/1
+f 3/2/2 7/14/2 8/4/2
+f 7/6/3 5/12/3 6/7/3
+f 2/9/4 4/5/4 8/10/4
+f 1/3/5 3/2/5 4/5/5
+f 5/12/6 1/3/6 2/9/6
diff --git a/simul/src/m3x3.rs b/simul/src/m3x3.rs
index 2737220..0ea5c8a 100644
--- a/simul/src/m3x3.rs
+++ b/simul/src/m3x3.rs
@@ -2,43 +2,69 @@ use std::ops::Mul;
 
 use crate::v3::V3;
 
-pub struct M3x3([f64; 9]);
+#[derive(Clone, Copy, Debug)]
+pub struct M3x3([[f64; 3]; 3]);
 
 impl M3x3 {
+    pub fn init(v: f64) -> Self {
+        Self([[v; 3]; 3])
+    }
+
+    pub fn from_v3_rot(rot: V3) -> Self {
+        M3x3::new_rotate_x(rot.0) * M3x3::new_rotate_y(rot.1) * M3x3::new_rotate_z(rot.2)
+    }
+
     #[rustfmt::skip]
     pub fn new_rotate_x(angle: f64) -> Self {
         Self([
-            1.0,             0.0,              0.0,
-            0.0, f64::cos(angle), -f64::sin(angle),
-            0.0, f64::sin(angle),  f64::cos(angle),
+            [1.0,             0.0,              0.0],
+            [0.0, f64::cos(angle), -f64::sin(angle)],
+            [0.0, f64::sin(angle),  f64::cos(angle)],
         ])
     }
 
     #[rustfmt::skip]
     pub fn new_rotate_y(angle: f64) -> Self {
         Self([
-             f64::cos(angle), 0.0, f64::sin(angle),
-                         0.0, 1.0,             0.0,
-            -f64::sin(angle), 0.0, f64::cos(angle),
+            [ f64::cos(angle), 0.0, f64::sin(angle)],
+            [             0.0, 1.0,             0.0],
+            [-f64::sin(angle), 0.0, f64::cos(angle)],
         ])
     }
 
     #[rustfmt::skip]
     pub fn new_rotate_z(angle: f64) -> Self {
         Self([
-            f64::cos(angle), -f64::sin(angle), 0.0,
-            f64::sin(angle),  f64::cos(angle), 0.0,
-                        0.0,              0.0, 1.0,
+            [f64::cos(angle), -f64::sin(angle), 0.0],
+            [f64::sin(angle),  f64::cos(angle), 0.0],
+            [            0.0,              0.0, 1.0],
         ])
     }
 }
 
+impl Mul for M3x3 {
+    type Output = M3x3;
+
+    fn mul(self, rhs: M3x3) -> Self::Output {
+        let mut output = M3x3([[0.0; 3]; 3]);
+        for i in 0..3 {
+            for j in 0..3 {
+                let v = &mut output.0[i][j];
+                for k in 0..3 {
+                    *v += self.0[i][k] * rhs.0[k][j];
+                }
+            }
+        }
+        output
+    }
+}
+
 impl Mul<V3> for M3x3 {
     type Output = V3;
 
     fn mul(self, rhs: V3) -> Self::Output {
         let V3(x, y, z) = rhs;
-        let [xx, xy, xz, yx, yy, yz, zx, zy, zz] = self.0;
+        let [[xx, xy, xz], [yx, yy, yz], [zx, zy, zz]] = self.0;
         V3(
             x * xx + y * xy + z * xz,
             x * yx + y * yy + z * yz,
diff --git a/simul/src/main.rs b/simul/src/main.rs
index f0378fc..e60e8e7 100644
--- a/simul/src/main.rs
+++ b/simul/src/main.rs
@@ -1,7 +1,12 @@
 #![allow(unused)]
 
+use std::{collections::HashMap, f64::consts::PI, fs::File, io::BufReader};
+
+use obj::{Obj, load_obj};
+
 use crate::{
-    scene::Scene,
+    m3x3::M3x3,
+    scene::{Model, Scene},
     tri2::Tri2,
     tri3::Tri3,
     v2::V2,
@@ -17,23 +22,89 @@ mod v2;
 mod v3;
 mod window;
 
-pub struct App {}
+struct AssetStore {
+    assets: HashMap<String, Obj>,
+}
+
+impl AssetStore {
+    fn new() -> Self {
+        Self {
+            assets: HashMap::new(),
+        }
+    }
+
+    fn load<S: Into<String>>(&mut self, path: S) -> Obj {
+        let path = path.into();
+        if self.assets.contains_key(&path) {
+            return self.assets.get(&path).unwrap().clone();
+        }
+        let asset: Obj = load_obj(BufReader::new(File::open(&path).unwrap())).unwrap();
+        self.assets.insert(path, asset.clone());
+        asset
+    }
+
+    fn get<S: Into<String>>(&self, path: S) -> Option<Obj> {
+        let path = path.into();
+        self.assets.get(&path).cloned()
+    }
+}
+
+pub struct App {
+    assets: AssetStore,
+    rot: V3,
+}
+
+impl App {
+    pub fn new() -> Self {
+        Self {
+            assets: AssetStore::new(),
+            rot: V3::init(0.0),
+        }
+    }
+}
 
 impl<R: Renderer> window::App<R> for App {
-    fn update(&mut self, delta_time: std::time::Duration) {}
+    fn update(&mut self, delta_time: std::time::Duration) {
+        self.rot.0 += PI * 2.0 * delta_time.as_secs_f64() * 0.1;
+        self.rot.1 += PI * 2.0 * delta_time.as_secs_f64() * 0.1;
+    }
 
     fn render(&self, r: &mut R) {
-        r.draw_line(V2(0.0, 0.0), V2(0.6, 0.2), Color::RED);
-
         let mut scene = Scene::new();
 
-        scene.draw_triangle(
-            Tri3(V3(0.0, 0.0, 0.0), V3(0.3, 0.3, 0.0), V3(0.3, 0.0, 0.0)),
-            Color::GREEN,
-            Color::BLACK,
+        // let mut model1 = Model::new();
+        // model1
+        //     .add_tri(
+        //         Tri3(V3(0.0, 0.0, 0.0), V3(0.3, 0.3, 0.0), V3(0.3, 0.0, 0.0)),
+        //         Color::RGB(200, 200, 200),
+        //     )
+        //     .rotate_by_m3x3(M3x3::from_v3_rot(self.rot))
+        //     .translate(V3(1.0, 0.0, 2.0))
+        //     .scale(V3(1.0, 1.0, 1.0));
+        //
+        // scene.draw_model(model1);
+
+        let mut model2 = Model::new();
+
+        let cube_obj = self.assets.get("assets/cube.obj").unwrap();
+        model2
+            .add_obj(&cube_obj, Color::RGB(165, 125, 165))
+            .rotate_by_m3x3(M3x3::from_v3_rot(self.rot))
+            .scale(V3(0.2, 0.2, 0.2))
+            .translate(V3(0.0, 0.0, 1.0));
+
+        scene.draw_model(model2);
+
+        // scene.draw_obj(&cube_obj, V3(0.1, 0.1, 0.1), Color::RGB(125, 125, 125));
+
+        scene.render(
+            r,
+            V3(0.0, 0.0, 0.0),
+            M3x3::from_v3_rot(V3(0.0, 0.0, 0.0)),
+            V3(0.0, 0.0, 1.0),
         );
 
-        scene.render(r, V3(0.0, 0.0, -1.0));
+        // r.draw_line(V2(0.0, 0.0), V2(0.6, 0.2), Color::RED);
     }
 
     fn event(&mut self, event: Event) {}
@@ -41,7 +112,8 @@ impl<R: Renderer> window::App<R> for App {
 
 fn main() {
     let mut window = Window::new();
-    let mut app = App {};
+    let mut app = App::new();
+    app.assets.load("assets/cube.obj");
 
     window.run(&mut app);
 }
diff --git a/simul/src/scene.rs b/simul/src/scene.rs
index a425405..bd01c56 100644
--- a/simul/src/scene.rs
+++ b/simul/src/scene.rs
@@ -1,4 +1,7 @@
+use obj::Obj;
+
 use crate::{
+    m3x3::M3x3,
     tri2::Tri2,
     tri3::Tri3,
     v3::V3,
@@ -6,7 +9,7 @@ use crate::{
 };
 
 pub struct Scene {
-    tris: Vec<(Tri3, Color, Color)>,
+    tris: Vec<(Tri3, V3, Color)>,
 }
 
 impl Scene {
@@ -14,7 +17,13 @@ impl Scene {
         Self { tris: Vec::new() }
     }
 
-    pub fn render(&self, r: &mut impl Renderer, camera_pos: V3) {
+    pub fn render(
+        &self,
+        r: &mut impl Renderer,
+        camera_pos: V3,
+        camera_rot: M3x3,
+        screen_rel_pos: V3,
+    ) {
         let mut indices_with_scores = self
             .tris
             .iter()
@@ -31,29 +40,102 @@ impl Scene {
         indices_with_scores.sort_by(|a, b| b.1.total_cmp(&a.1));
 
         for (i, _) in indices_with_scores {
-            let (tri3, outline_color, fill_color) = &self.tris[i];
+            let (tri3, normal, color) = &self.tris[i];
 
             // if !(tri3.0.2 >= -1.0 && tri3.1.2 >= -1.0 && tri3.2.2 >= -1.0) {
             //     continue;
             // }
 
-            // if tri3.normal().dot(tri3.0 - camera_pos) >= 0.0 {
+            // if normal.dot(camera_pos - tri3.0) < 0.0 {
             //     continue;
             // }
-            //
-            println!("{tri3:?}");
 
-            let tri2 = tri3.project_2d(camera_pos);
+            let tri2 = tri3.project_2d(camera_pos, camera_rot, screen_rel_pos);
 
-            println!("{tri2:?}");
-
-            r.draw_triangles(&[tri2], *fill_color);
-            r.draw_line(tri2.0, tri2.1, *outline_color);
-            r.draw_line(tri2.0, tri2.2, *outline_color);
+            r.draw_triangles(&[tri2], *color);
+            r.draw_line(tri2.0, tri2.1, Color::BLACK);
+            r.draw_line(tri2.1, tri2.2, Color::BLACK);
+            r.draw_line(tri2.2, tri2.0, Color::BLACK);
         }
     }
 
-    pub fn draw_triangle(&mut self, tri: Tri3, outline_color: Color, fill_color: Color) {
-        self.tris.push((tri, outline_color, fill_color));
+    pub fn draw_model(&mut self, model: Model) {
+        self.tris.extend(model.tris());
+    }
+
+    pub fn draw_triangle(&mut self, tri: Tri3, color: Color) {
+        self.tris.push((tri, tri.normal(), color));
+    }
+}
+
+pub struct Model {
+    tris: Vec<(Tri3, V3, Color)>,
+}
+
+impl Model {
+    pub fn new() -> Self {
+        Self { tris: Vec::new() }
+    }
+
+    pub fn tris(&self) -> impl Iterator<Item = (Tri3, V3, Color)> {
+        self.tris.iter().copied()
+    }
+
+    pub fn translate(&mut self, offset: V3) -> &mut Self {
+        for tri in &mut self.tris {
+            tri.0 = tri.0.translate(offset);
+        }
+        self
+    }
+
+    pub fn rotate_by_m3x3(&mut self, rot: M3x3) -> &mut Self {
+        for tri in &mut self.tris {
+            tri.0 = tri.0.rotate_by_m3x3(rot);
+        }
+        self
+    }
+
+    pub fn scale(&mut self, scale: V3) -> &mut Self {
+        for tri in &mut self.tris {
+            tri.0 = tri.0.scale(scale);
+        }
+        self
+    }
+
+    pub fn add_tri(&mut self, tri: Tri3, color: Color) -> &mut Self {
+        self.tris.push((tri, tri.normal(), color));
+        self
+    }
+
+    pub fn add_obj(&mut self, obj: &Obj, color: Color) -> &mut Self {
+        let count = obj.indices.len() / 3;
+        for i in 0..count {
+            let v0 = obj.vertices[obj.indices[i * 3] as usize];
+            let v1 = obj.vertices[obj.indices[i * 3 + 1] as usize];
+            let v2 = obj.vertices[obj.indices[i * 3 + 2] as usize];
+
+            self.tris.push((
+                Tri3(
+                    V3(
+                        v0.position[0] as _,
+                        v0.position[1] as _,
+                        v0.position[2] as _,
+                    ),
+                    V3(
+                        v1.position[0] as _,
+                        v1.position[1] as _,
+                        v1.position[2] as _,
+                    ),
+                    V3(
+                        v2.position[0] as _,
+                        v2.position[1] as _,
+                        v2.position[2] as _,
+                    ),
+                ),
+                V3(v0.normal[0] as _, v0.normal[1] as _, v0.normal[2] as _),
+                color,
+            ));
+        }
+        self
     }
 }
diff --git a/simul/src/tri3.rs b/simul/src/tri3.rs
index cc159fd..c0af797 100644
--- a/simul/src/tri3.rs
+++ b/simul/src/tri3.rs
@@ -1,4 +1,4 @@
-use crate::{tri2::Tri2, v3::V3};
+use crate::{m3x3::M3x3, tri2::Tri2, v3::V3};
 
 #[derive(Clone, Copy, Debug)]
 pub struct Tri3(pub V3, pub V3, pub V3);
@@ -20,20 +20,27 @@ impl Tri3 {
         )
     }
 
-    pub fn rotate(&self, rot: V3) -> Self {
-        self.map(|v| v.rotate(rot))
+    pub fn rotate_by_v3(&self, rot: V3) -> Self {
+        self.map(|v| v.rotate_by_v3(rot))
+    }
+    pub fn rotate_by_m3x3(&self, rot: M3x3) -> Self {
+        self.map(|v| v.rotate_by_m3x3(rot))
     }
 
-    pub fn project_2d(&self, camera_pos: V3) -> Tri2 {
+    pub fn project_2d(&self, camera_pos: V3, camera_rot: M3x3, screen_rel_pos: V3) -> Tri2 {
         Tri2(
-            self.0.project_2d(camera_pos),
-            self.1.project_2d(camera_pos),
-            self.2.project_2d(camera_pos),
+            self.0.project_2d(camera_pos, camera_rot, screen_rel_pos),
+            self.1.project_2d(camera_pos, camera_rot, screen_rel_pos),
+            self.2.project_2d(camera_pos, camera_rot, screen_rel_pos),
         )
     }
 
     pub fn translate(&self, offset: V3) -> Self {
-        self.map(|v| v + offset)
+        self.map(|v| v.translate(offset))
+    }
+
+    pub fn scale(&self, scale: V3) -> Self {
+        self.map(|v| v.scale(scale))
     }
 
     pub fn points(&self) -> [V3; 3] {
diff --git a/simul/src/v2.rs b/simul/src/v2.rs
index 57ff770..1c34a80 100644
--- a/simul/src/v2.rs
+++ b/simul/src/v2.rs
@@ -19,8 +19,7 @@ impl V2 {
     pub fn reduce<F: Fn(f64, f64) -> f64>(&self, initial: f64, func: F) -> f64 {
         let acc = initial;
         let acc = func(acc, self.0);
-        let acc = func(acc, self.1);
-        acc
+        func(acc, self.1)
     }
 
     pub fn normal(&self) -> V2 {
diff --git a/simul/src/v3.rs b/simul/src/v3.rs
index d46ed89..f059eda 100644
--- a/simul/src/v3.rs
+++ b/simul/src/v3.rs
@@ -26,25 +26,31 @@ impl V3 {
         let acc = initial;
         let acc = func(acc, self.0);
         let acc = func(acc, self.1);
-        let acc = func(acc, self.0);
-        acc
+        func(acc, self.0)
     }
 
-    pub fn cross(&self, rhs: Self) -> Self {
+    pub fn cross(&self, rhs: V3) -> Self {
         let V3(ax, ay, az) = self;
         let V3(bx, by, bz) = rhs;
         V3(ay * bz - az * by, az * bx - ax * bz, ax * by - ay * bx)
     }
 
-    pub fn rotate(&self, rot: Self) -> Self {
+    pub fn rotate_by_v3(&self, rot: V3) -> Self {
         M3x3::new_rotate_z(rot.2)
             * (M3x3::new_rotate_y(rot.1) * (M3x3::new_rotate_x(rot.0) * *self))
     }
 
-    pub fn project_2d(&self, camera_pos: V3) -> V2 {
+    pub fn rotate_by_m3x3(&self, rot: M3x3) -> Self {
+        rot * *self
+    }
+
+    /// See https://en.wikipedia.org/wiki/3D_projection#Mathematical_formula
+    /// for details on the implementation.
+    pub fn project_2d(&self, camera_pos: V3, camera_rot: M3x3, screen_rel_pos: V3) -> V2 {
+        let a = *self;
         let c = camera_pos;
-        let d = *self - c;
-        let e = V3(0.0, 0.0, 0.0) - c;
+        let d = (a - c).rotate_by_m3x3(camera_rot);
+        let e = screen_rel_pos - c;
         V2(e.2 / d.2 * d.0 + e.0, e.2 / d.2 * d.1 + e.1)
     }
 
@@ -52,8 +58,12 @@ impl V3 {
         self.zip(rhs, |a, b| a * b).reduce(0.0, |acc, v| acc + v)
     }
 
-    pub fn translate(&self, trans: V3) -> V3 {
-        *self + trans
+    pub fn translate(&self, offset: Self) -> Self {
+        *self + offset
+    }
+
+    pub fn scale(&self, scale: Self) -> Self {
+        self.zip(scale, |a, b| a * b)
     }
 
     pub fn len(&self) -> f64 {
diff --git a/simul/src/window.rs b/simul/src/window.rs
index b69f7fc..99daf7d 100644
--- a/simul/src/window.rs
+++ b/simul/src/window.rs
@@ -88,7 +88,7 @@ impl Window {
             time_before = time_now;
             app.update(delta_time);
 
-            self.canvas.set_draw_color(Color::RGB(20, 20, 20));
+            self.canvas.set_draw_color(Color::RGB(30, 30, 30));
             self.canvas.clear();
             app.render(self);
             self.canvas.present();