wip: normal material

src/camera.rs

@@ -1,6 +1,6 @@
 use std::{f32::consts::PI, sync::Arc};
 
-use log::info;
+use log::{info, warn};
 
 use crate::{
     objects::{hit::Hit, traits::Hittable},

src/objects/cube.rs

@@ -44,6 +44,7 @@ impl Hittable for Cube {
     }
 
     fn normal_at(&self, p: &Vec3) -> Vec3 {
+        // TODO: normal calc for cube
         todo!()
     }
 }

src/objects/hit.rs

@@ -45,6 +45,7 @@ impl Hit {
         self.front_face
     }
 
+    // TODO: use front_face to discard back-hits for culling
     pub fn hit_list(hittables: &Vec<Arc<dyn Hittable>>, r: &Ray) -> Option<Hit> {
         let mut closest: Option<Hit> = None;
         for hittable in hittables {

src/objects/materials.rs

@@ -1,3 +1,4 @@
 pub mod dielectric;
 pub mod lambertian;
+pub mod normal;
 pub mod traits;

src/objects/materials/normal.rs

@@ -0,0 +1,17 @@
+use serde::Deserialize;
+
+use crate::{
+    objects::{hit::Hit, materials::traits::Material},
+    ray::Ray,
+    vec3::Vec3,
+};
+
+#[derive(Debug, Deserialize)]
+pub struct Normal {}
+
+impl Material for Normal {
+    fn scatter(&self, hit: &Hit, ray: &Ray) -> Option<(Ray, Vec3)> {
+        let refl = ray.dir().reflect(hit.n()).get_unit();
+        Some((Ray::new(*hit.p(), refl), (hit.n() + 1.) / 2.))
+    }
+}

src/objects/quad.rs

@@ -4,7 +4,7 @@ use crate::objects::traits::Hittable;
 use crate::objects::triangle::Triangle;
 use crate::ray::Ray;
 use crate::{objects::materials::traits::Material, vec3::Vec3};
-use log::info;
+use log::{info, warn};
 use std::fmt::Debug;
 use std::sync::Arc;
 
@@ -19,6 +19,7 @@ pub struct Quad {
 
 impl Quad {
     pub fn new(p1: Vec3, p2: Vec3, p3: Vec3, p4: Vec3, material: Arc<dyn Material>) -> Self {
+        warn!("quad normal {}", (p2 - p1).cross(&(p4 - p1)).get_unit());
         Self {
             p1,
             p2,

src/objects/triangle.rs

@@ -1,5 +1,3 @@
-use log::{info, warn};
-
 use crate::objects::hit::Hit;
 use crate::objects::traits::Hittable;
 use crate::ray::Ray;
@@ -56,7 +54,7 @@ impl Triangle {
 
         let diff = (a4 - a1 - a2 - a3).abs();
         if diff < 0.001 {
-            return Some(Hit::new(t, p, normal, material, normal.dot(&-r.dir()) < 0.));
+            return Some(Hit::new(t, p, normal, material, normal.dot(&-r.dir()) > 0.));
         } else {
             return None;
         }

src/scenes/scene.rs

@@ -11,6 +11,7 @@ use crate::{
         materials::{
             dielectric::Dielectric,
             lambertian::{Lambertian, Metal},
+            normal::Normal,
             traits::Material,
         },
         quad::Quad,
@@ -207,6 +208,7 @@ enum MaterialDef {
     Lambertian(Lambertian),
     Metal(Metal),
     Dielectric(Dielectric),
+    Normal(Normal),
 }
 
 impl MaterialDef {
@@ -215,6 +217,7 @@ impl MaterialDef {
             MaterialDef::Lambertian(l) => Arc::new(l),
             MaterialDef::Metal(m) => Arc::new(m),
             MaterialDef::Dielectric(d) => Arc::new(d),
+            MaterialDef::Normal(n) => Arc::new(n),
         }
     }
 }

src/vec3.rs

@@ -1,5 +1,6 @@
 use core::f32::math::sqrt;
 use is_close::default;
+use log::warn;
 use rand::RngExt;
 use serde::{Deserialize, Serialize, Serializer};
 use std::{