wip: normal material

scenes/scene.json

@@ -4,9 +4,9 @@
     "image_height": 1080,
     "anti_alias_rate": 1,
     "max_depth": 50,
-    "fov": 50.0,
-    "look_from": [15, 4, 10],
-    "look_at": [10.0, 2.0, 0.0], 
+    "fov": 10.0,
+    "look_from": [0, 4, 15],
+    "look_at": [0.0, 0.0, 0.0], 
     "vup": [0.0, 1.0, 0.0],
     "defocus_angle": 0,
     "focus_dist": 15.68
@@ -14,20 +14,21 @@
   "materials": [
     { "type": "lambertian", "albedo": [0.2, 0.2, 0.2], "prob": 0.8 },
     { "type": "lambertian", "albedo": [0.9, 0.9, 0.0], "prob": 1.0, "fuzz": 0.1 },
-    { "type": "dielectric", "refraction_index": 1.5}
+    { "type": "dielectric", "refraction_index": 1.5},
+    { "type": "normal"}
  ],
   "objects": [
     { "type": "sphere", "center": [0.0, 0.0, -1.2], "radius": 0.5, "material": { "type": "metal", "albedo": [0.7, 0.4, 0.2], "prob": 1.0, "fuzz": 0.1 }},
-    { "type": "sphere", "center": [-1, 0, -1], "radius": 0.4, "material": 2},
+    { "type": "sphere", "center": [-1, 0, -1], "radius": 0.4, "material": 3},
     { "type": "sphere", "center": [1, 0, -1], "radius": 0.5, "material": { "type": "metal", "albedo": [0.8, 0.6, 0.2], "prob": 1.0, "fuzz": 1.0 }},
     { "type": "triangle", "p1": [-4, 0, -4], "p2": [0, 0, -4], "p3": [-2, 2, -4], "material": 1},
     { "type": "triangle", "p1": [0, 0, -4], "p2": [4, 0, -4], "p3": [2, 2, -4], "material": 1},
-    { "type": "triangle", "p1": [-2, 2, -4], "p2": [2, 2, -4], "p3": [0, 4, -4], "material": 1},
+    { "type": "triangle", "p1": [-2, 2, -4], "p2": [2, 2, -4], "p3": [0, 4, -4], "material": 3},
     { "type": "quad", "p1": [-20, -1, -20], "p2": [20, -1, -20], "p3": [20, 20, -20], "p4": [-20, 20, -20], "material": 0},
     { "type": "quad", "p1": [-20, -1, 20], "p2": [-20, -1, -20], "p3": [-20, 20, -20], "p4": [-20, 20, 20], "material": 0},
     { "type": "quad", "p1": [-20, -1, 20], "p2": [20, -1, 20], "p3": [20, -1, -20], "p4": [-20, -1, -20], "material": 0},
     { "type": "quad", "p1": [20, -1, 20], "p2": [20, -1, -20], "p3": [20, 20, -20], "p4": [20, 20, 20], "material": 0},
-    { "type": "cube", "p1": [8, 0, 2], "p2": [12, 0, 2], "p3": [12, 4, 2], "p4": [8, 4, 2], "p5": [8, 0, -2], "p6": [12, 0, -2], "p7": [12, 4, -2], "p8": [8, 4, -2], "material": 1}
+    { "type": "cube", "p1": [8, 0, 2], "p2": [12, 0, 2], "p3": [12, 4, 2], "p4": [8, 4, 2], "p5": [8, 0, -2], "p6": [12, 0, -2], "p7": [12, 4, -2], "p8": [8, 4, -2], "material": 3}
  ]
 }
 

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::{