diff --git a/main.cpp b/main.cpp
index 115b234..e2cda12 100644
--- a/main.cpp
+++ b/main.cpp
@@ -18,22 +18,28 @@
 #include "moving_sphere.h"
 #include "camera.h"
 
-Color ray_color(const Ray& r, const Hittable& world, int depth) {
+Color ray_color(const Ray& r, const Color& background, const Hittable& world, int depth) {
     hit_record rec;
 
     if (depth <= 0)
         return Color(0, 0, 0);
 
-    if (world.hit(r, 0.001, infinity, rec)) {
-        Ray scattered;
-        Color attenuation;
-        if (rec.mat_ptr->scatter(r, rec, attenuation, scattered))
-          return attenuation * ray_color(scattered, world, depth - 1);
-        return Color(0, 0, 0);
-    }
-    Vec3 unit_direction = unit_vector(r.direction());
+    if (!world.hit(r, 0.001, infinity, rec))
+        return background;
+
+    Ray scattered;
+    Color attenuation;
+    Color emitted = rec.mat_ptr->emitted(rec.u, rec.v, rec.p);
+
+    if (!rec.mat_ptr->scatter(r, rec, attenuation, scattered))
+        return emitted;
+
+    return emitted + attenuation * ray_color(scattered, background, world, depth - 1);
+
+    // fading background
+    /*Vec3 unit_direction = unit_vector(r.direction());
     auto t = 0.5 * (unit_direction.y() + 1.0);
-    return (1.0 - t) * Color(1.0, 1.0, 1.0) + t * Color(0.5, 0.7, 1.0);
+    return (1.0 - t) * Color(1.0, 1.0, 1.0) + t * Color(0.5, 0.7, 1.0);*/
 }
 
 Bvh_node setup_random_scene(const int sph_i) {
@@ -123,9 +129,12 @@ int main() {
     const int image_width = 768;
     //const int image_width = 384;
     const int image_height = static_cast<int>(image_width / aspect_ratio);
+    //const int samples_per_pixel = 10000;
+    //const int samples_per_pixel = 5000;
     //const int samples_per_pixel = 2000;
-    //const int samples_per_pixel = 1000;
-    const int samples_per_pixel = 400;
+    const int samples_per_pixel = 1000;
+    //const int samples_per_pixel = 400;
+    //const int samples_per_pixel = 50;
     const int max_depth = 50;
 
     const int tile_size = 128;
@@ -148,6 +157,7 @@ int main() {
     //auto aperture = 0.0;
 
     Camera cam(lookfrom, lookat, vup, 20, aspect_ratio, aperture, dist_to_focus, 0.0, 1.0);
+    const Color background(0, 0, 0);
 
     std::atomic<int> queue_counter;
     boost::lockfree::queue<render_tile> queue(0);
@@ -181,8 +191,8 @@ int main() {
                     for (int s = 0; s<samples_per_pixel; ++s) {
                         auto u = double(j + random_double(-0.5, 0.5)) / (image_width - 1);
                         auto v = double(i + random_double(-0.5, 0.5)) / (image_height - 1);
-                        Ray r = cam.get_ray(u, v);
-                        pixel_color += ray_color(r, world, max_depth);
+                        Ray r = camera.get_ray(u, v);
+                        pixel_color += ray_color(r, background, world, max_depth);
                     }
                     image[i*image_width+j] = pixel_color;
                 }
diff --git a/material.h b/material.h
index ab607be..6639f9a 100644
--- a/material.h
+++ b/material.h
@@ -10,6 +10,7 @@ struct hit_record;
 class Material {
 public:
   virtual bool scatter(const Ray& r_in, const hit_record& rec, Color& attenuation, Ray& scattered) const = 0;
+  virtual Color emitted(double u, double v, const Point3& p) const { return Color(0, 0, 0); }
 };
 
 class Lambertian : public Material {
@@ -42,4 +43,18 @@ private:
   double ref_idx;
 };
 
+class Diffuse_light : public Material {
+  public:
+    Diffuse_light(std::shared_ptr<Texture> a) : emit(a) {}
+
+    virtual bool scatter(const Ray& r_in, const hit_record& rec, Color& attenuation, Ray& scattered) const {
+        return false;
+    }
+
+    virtual Color emitted(double u, double v, const Point3& p) const { return emit->value(u, v, p); }
+
+  private:
+    std::shared_ptr<Texture> emit;
+};
+
 #endif // MATERIAL_H