First quick pass at loading OBJ files.

Cargo.toml

@@ -7,9 +7,12 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-sdl2 = "0.32"
+alga = "0.9"
+itertools = "0.8"
+obj = "0.9"
 quickcheck = "0.9"
 quickcheck_macros = "0.8"
+sdl2 = "0.32"
 
 [dependencies.nalgebra]
 version = "0.19"

src/main.rs

@@ -7,15 +7,17 @@ use std::time::Duration;
 
 use nalgebra::{Point3, Vector3};
 
+
 use std::cmp::min;
 use std::rc::Rc;
+use std::path::Path;
 
 use vanrijn::camera::partial_render_scene;
 use vanrijn::colour::{ColourRgbF, NamedColour};
 use vanrijn::image::{ClampingToneMapper, ImageRgbF, ImageRgbU8, ToneMapper};
 use vanrijn::materials::{LambertianMaterial, PhongMaterial, ReflectiveMaterial};
-use vanrijn::mesh::Triangle;
+use vanrijn::mesh::{load_obj, Triangle};
-use vanrijn::raycasting::{Plane, Sphere};
+use vanrijn::raycasting::{Intersect, Plane, Sphere};
 use vanrijn::scene::Scene;
 
 fn update_texture(image: &ImageRgbU8, texture: &mut Texture) {
@@ -59,9 +61,20 @@ pub fn main() -> Result<(), Box<dyn std::error::Error>> {
     )?;
     let mut output_image = ImageRgbF::<f64>::new(image_width, image_height);
 
-    let scene = Scene {
+    let scene = Arc::new(Scene {
-        camera_location: Point3::new(0.0, 0.0, 0.0),
+        camera_location: Point3::new(-2.0, 1.0, -5.0),
-        objects: vec![
+        objects: load_obj(
+            Path::new("/home/matthew/Downloads/bunny.obj"),
+            Arc::new(ReflectiveMaterial {
+                colour: ColourRgbF::from_named(NamedColour::Yellow),
+                diffuse_strength: 0.05,
+                reflection_strength: 0.9,
+            }),
+        )
+        .unwrap()
+        .into_iter()
+        .map(|triangle| Box::new(triangle) as Box<dyn Intersect<f64>>)
+        .chain(vec![
             Box::new(Plane::new(
                 Vector3::new(0.0, 1.0, 0.0),
                 -2.0,
@@ -69,17 +82,17 @@ pub fn main() -> Result<(), Box<dyn std::error::Error>> {
                     colour: ColourRgbF::new(0.55, 0.27, 0.04),
                     diffuse_strength: 0.1,
                 }),
-            )),
+            )) as Box<dyn Intersect<f64>>,
             Box::new(Sphere::new(
-                Point3::new(1.25, -0.5, 6.0),
+                Point3::new(-6.25, -0.5, 1.0),
                 1.0,
-                Rc::new(LambertianMaterial {
+                Arc::new(LambertianMaterial {
                     colour: ColourRgbF::from_named(NamedColour::Green),
                     diffuse_strength: 0.1,
                 }),
             )),
             Box::new(Sphere::new(
-                Point3::new(-1.25, -0.5, 6.0),
+                Point3::new(-4.25, -0.5, 2.0),
                 1.0,
                 Rc::new(ReflectiveMaterial {
                     colour: ColourRgbF::from_named(NamedColour::Blue),
@@ -88,7 +101,7 @@ pub fn main() -> Result<(), Box<dyn std::error::Error>> {
                 }),
             )),
             Box::new(Sphere::new(
-                Point3::new(0.0, 1.5, 6.0),
+                Point3::new(-5.0, 1.5, 1.0),
                 1.0,
                 Rc::new(PhongMaterial {
                     colour: ColourRgbF::from_named(NamedColour::Red),
@@ -97,20 +110,9 @@ pub fn main() -> Result<(), Box<dyn std::error::Error>> {
                     specular_strength: 1.0,
                 }),
             )),
-            Box::new(Triangle {
+        ])
-                vertices: [
+        .collect(),
-                    Point3::new(1.25, -0.5, 6.0),
+    });
-                    Point3::new(-1.25, -0.5, 6.0),
-                    Point3::new(0.0, 1.5, 6.0),
-                ],
-                normals: [Vector3::new(0.0, 0.0, 1.0); 3],
-                material: Rc::new(LambertianMaterial {
-                    colour: ColourRgbF::from_named(NamedColour::Green),
-                    diffuse_strength: 0.1,
-                }),
-            }),
-        ],
-    };
 
     let mut event_pump = sdl_context.event_pump()?;
     let mut i = 0;

src/mesh.rs

@@ -1,10 +1,15 @@
-use nalgebra::{Point3, RealField, Vector2, Vector3};
+use nalgebra::{convert, Point3, RealField, Vector2, Vector3};
+use obj::{IndexTuple, Obj, SimplePolygon};
 
 use super::materials::Material;
 use super::raycasting::{Intersect, IntersectionInfo, Ray};
 
 use std::rc::Rc;
+use alga::general::SupersetOf;
+use std::io::Result;
+use std::path::Path;
 
+#[derive(Debug)]
 pub struct Triangle<T: RealField> {
     pub vertices: [Point3<T>; 3],
     pub normals: [Vector3<T>; 3],
@@ -76,6 +81,76 @@ impl<T: RealField> Intersect<T> for Triangle<T> {
     }
 }
 
+fn get_vertex_and_normal<T: RealField>(
+    index_tuple: &IndexTuple,
+    vertex_positions: &Vec<[f32; 3]>,
+    normal_positions: &Vec<[f32; 3]>,
+) -> (Point3<T>, Vector3<T>)
+where
+    T: SupersetOf<f32>,
+{
+    let &IndexTuple(vertex_index, _, maybe_normal_index) = index_tuple;
+    let vertex: Point3<T> = convert(Point3::from_slice(&vertex_positions[vertex_index]));
+    let normal = match maybe_normal_index {
+        Some(normal_index) => convert(Vector3::from_row_slice(&normal_positions[normal_index])),
+        None => Vector3::zeros(),
+    };
+    (vertex, normal)
+}
+
+fn get_triangles<T: RealField>(
+    polygon: &SimplePolygon,
+    vertex_positions: &Vec<[f32; 3]>,
+    normal_positions: &Vec<[f32; 3]>,
+    material: Arc<dyn Material<T>>,
+) -> Vec<Triangle<T>>
+where
+    T: SupersetOf<f32>,
+{
+    if let Some(v0_index) = polygon.iter().next() {
+        let (v0_vertex, v0_normal) =
+            get_vertex_and_normal(v0_index, &vertex_positions, &normal_positions);
+        polygon
+            .iter()
+            .skip(1)
+            .zip(polygon.iter().skip(2))
+            .map(|(v1_index, v2_index)| {
+                let (v1_vertex, v1_normal) =
+                    get_vertex_and_normal(v1_index, &vertex_positions, &normal_positions);
+                let (v2_vertex, v2_normal) =
+                    get_vertex_and_normal(v2_index, &vertex_positions, &normal_positions);
+                let vertices = [v0_vertex, v1_vertex, v2_vertex];
+                let normals = [v0_normal, v1_normal, v2_normal];
+                Triangle {
+                    vertices,
+                    normals,
+                    material: material.clone(),
+                }
+            })
+            .collect()
+    } else {
+        vec![]
+    }
+}
+
+pub fn load_obj<T: RealField>(
+    filename: &Path,
+    material: Arc<dyn Material<T>>,
+) -> Result<Vec<Triangle<T>>>
+where
+    T: SupersetOf<f32>,
+{
+    let obj = Obj::<SimplePolygon>::load(filename)?;
+
+    Ok(obj
+        .objects
+        .iter()
+        .flat_map(|object| object.groups.iter())
+        .flat_map(|group| group.polys.iter())
+        .flat_map(|poly| get_triangles(poly, &obj.position, &obj.normal, material.clone()))
+        .collect())
+}
+
 fn indices_with_index_of_largest_element_last<T: RealField>(v: &Vector3<T>) -> [usize; 3] {
     if v.x > v.y {
         if v.z > v.x {