diff --git a/reaction/code/game/bg_misc.c b/reaction/code/game/bg_misc.c
index 48363257..d02ce9db 100644
--- a/reaction/code/game/bg_misc.c
+++ b/reaction/code/game/bg_misc.c
@@ -1816,3 +1816,8 @@ float SawTooth(int time, int period)
 			return 1.0f - (time % period) / ((float)period);
 	}
 }
+
+float SmoothLerp(float x)
+{
+	return x * x * (3.f - 2.f * x);
+}
diff --git a/reaction/code/game/bg_public.h b/reaction/code/game/bg_public.h
index 15a3abdd..9954c36f 100644
--- a/reaction/code/game/bg_public.h
+++ b/reaction/code/game/bg_public.h
@@ -1628,6 +1628,7 @@ int GetMaterialFromFlag(int flag);
 
 
 float SawTooth(int time, int period);
+float SmoothLerp(float x);
 
 #define PULSE_SAWTOOTH_PERIOD		500
 #define ARRAY_SIZE(arr)				(sizeof(arr) / sizeof(arr[0]))