diff --git a/assignment-1/src/main.rs b/assignment-1/src/main.rs
index dc1df78..4d01571 100644
--- a/assignment-1/src/main.rs
+++ b/assignment-1/src/main.rs
@@ -1,13 +1,15 @@
 mod input_file;
 mod ray;
 mod scene_data;
-mod view;
 mod vec3;
+mod view;
 
 use std::path::PathBuf;
 
 use anyhow::Result;
 use clap::Parser;
+use vec3::Vec3;
+use view::Rect;
 
 use crate::input_file::parse_input_file;
 
@@ -32,10 +34,24 @@ fn main() -> Result<()> {
 
   let scene = parse_input_file(&opt.input_path)?;
 
-  // Loop through every single pixel of the output file
-  for (px, py) in (0..scene.image_width).zip(0..scene.image_height) {
+  // Compute viewing directions
+  let u = Vec3::cross(scene.view_dir, scene.up_dir).unit();
+  let v = Vec3::cross(u, scene.view_dir).unit();
 
-  }
+  // Compute viewing window corners
+  // TODO: See slide 101
+  // Also need to reverse calculation for d based on hfov
+  let n = scene.view_dir.unit();
+  let d = 1.0;
+  let view_window = Rect {
+    upper_left: scene.eye_pos + n * d, // + ...
+    upper_right: scene.eye_pos + n * d,
+    lower_left: scene.eye_pos + n * d,
+    lower_right: scene.eye_pos + n * d,
+  };
+
+  // Loop through every single pixel of the output file
+  for (px, py) in (0..scene.image_width).zip(0..scene.image_height) {}
 
   Ok(())
 }
diff --git a/assignment-1/src/vec3.rs b/assignment-1/src/vec3.rs
index 77495da..4c7aee9 100644
--- a/assignment-1/src/vec3.rs
+++ b/assignment-1/src/vec3.rs
@@ -16,6 +16,7 @@ impl<T> Vec3<T> {
 }
 
 impl<T: Float> Vec3<T> {
+  /// Cross product on floats
   pub fn cross(u: Self, v: Self) -> Self {
     Vec3::new(
       u.y * v.z - u.z * v.y,
@@ -23,6 +24,16 @@ impl<T: Float> Vec3<T> {
       u.x * v.y - u.y * v.x,
     )
   }
+
+  pub fn norm(&self) -> T {
+    (self.x.powi(2) + self.y.powi(2) + self.z.powi(2)).sqrt()
+  }
+
+  /// Normalize
+  pub fn unit(&self) -> Self {
+    let norm = self.norm();
+    Vec3::new(self.x / norm, self.y / norm, self.z / norm)
+  }
 }
 
 /// Vector addition