fix threshold

src/lib.rs

@@ -252,7 +252,7 @@ impl Core {
 			let mut value = 0.0f32;
 			for light_hit in &hits {
 				let d2 = hit.incident.base.distance_squared(light_hit.incident.base);
-				if d2 > 3. * sigma2 {
+				if d2 > 9. * sigma2 {
 					continue;
 				}
 				assert!(hit.incident.dir.is_normalized());