Fix hopefully last nan for iridescent material

ray-tracing-tev/src/main.rs

@@ -51,9 +51,13 @@ fn render_image<
         for _ in 0..samples_per_pixel {
             let r =
                 renderer.render_pixel(scene, camera, x, y, &mut rng) / (samples_per_pixel as Float);
-            c[0] += r.r();
-            c[1] += r.g();
-            c[2] += r.b();
+            if r.r().is_nan() || r.g().is_nan() || r.b().is_nan() {
+                eprintln!("NAN x: {:?}, y: {:?}, r: {:?}", x, y, r);
+            } else {
+                c[0] += r.r();
+                c[1] += r.g();
+                c[2] += r.b();
+            }
         }
     });
     println!("Rendered \"{}\" in {:?}", name.as_ref(), start.elapsed());