1 files changed, 3 insertions, 2 deletions
diff --git a/sphere.h b/sphere.h
index c27f29b..3cb2c8c 100644
--- a/sphere.h
+++ b/sphere.h
@@ -10,9 +10,10 @@
 #include <tuple>
 
 enum class Material : int {
-    Lambertian,
+    Lambertian = 0,
     Metal,
-    Dielectric
+    Dielectric,
+    Undefined
 };
 
 struct Sphere