From de16463c4ed8244f18201f77529ff38cfd4c73f5 Mon Sep 17 00:00:00 2001
From: JonOfUs <jonathan@flueren.eu>
Date: Wed, 1 Jun 2022 16:49:39 +0200
Subject: [PATCH] hit check normal vec angle

---
 src/hittable.rs | 6 ++++--
 src/main.rs     | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/hittable.rs b/src/hittable.rs
index 8c9c728..f77a8de 100644
--- a/src/hittable.rs
+++ b/src/hittable.rs
@@ -71,9 +71,11 @@ impl Hittable for Sphere {
         let sqrtd = discriminant.sqrt();
 
         let root = (-half_b - sqrtd) / a;
-        if root < t_min || t_max < root {
+        let normal = (r.at(root) - self.center) / self.radius;
+        if root < t_min || t_max < root || Vec3::dot(normal, r.direction()) > 0.0 {
             let root2 = (-half_b + sqrtd) / a;
-            if root2 < t_min || t_max < root {
+            let normal = (r.at(root2) - self.center) / self.radius;
+            if root2 < t_min || t_max < root || Vec3::dot(normal, r.direction()) > 0.0 {
                 return false;
             }
         }
diff --git a/src/main.rs b/src/main.rs
index 5533084..1a9bbc3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -26,7 +26,7 @@ fn ray_color(r: &Ray, world: &HittableList, depth: u32) -> Color {
         return Color::new(0.0,0.0,0.0);
     }
 
-    if world.hit(r, 0.001, f64::INFINITY, &mut rec) {
+    if world.hit(r, 0.0, f64::INFINITY, &mut rec) {
         let target = rec.p + rec.normal + Vec3::random_in_unit_sphere();
         return 0.5 * ray_color(&Ray::new(rec.p, target - rec.p), world, depth-1);
     }