diff --git a/language.version b/language.version
index 1514075ff..a0c2afc04 100644
--- a/language.version
+++ b/language.version
@@ -1,3 +1,3 @@
 [default]
-SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r520 \cu(Tue 27 Sep 21:46:09 CEST 2022)\c-";
-SWWM_SHORTVER="\cw1.3pre r520 \cu(2022-09-27 21:46:09)\c-";
+SWWM_MODVER="\cyDEMOLITIONIST \cw1.3pre r521 \cu(Wed 28 Sep 13:49:54 CEST 2022)\c-";
+SWWM_SHORTVER="\cw1.3pre r521 \cu(2022-09-28 13:49:54)\c-";
diff --git a/zscript/utility/swwm_utility.zsc b/zscript/utility/swwm_utility.zsc
index 32ec5ddfd..de7d7424c 100644
--- a/zscript/utility/swwm_utility.zsc
+++ b/zscript/utility/swwm_utility.zsc
@@ -626,6 +626,22 @@ Class SWWMUtility
 		return (distsq <= (radius*radius));
 	}
 
+	// hitscan exit point calculation given actor, entry point and direction
+	static clearscope Vector3 TraceExit( Actor a, Vector3 p, Vector3 d )
+	{
+		Vector3 ap = p+level.Vec3Diff(p,a.pos);	// portal-relative actor position
+		Vector3 amin = ap+(-a.radius,-a.radius,0),
+			amax = ap+(a.radius,a.radius,a.height);
+		Vector3 tmax, div = (1./d.x,1./d.y,1./d.z);
+		if ( div.x < 0 ) tmax.x = (amin.x-p.x)*div.x;
+		else tmax.x = (amax.x-p.x)*div.x;
+		if ( div.y < 0 ) tmax.y = (amin.y-p.y)*div.y;
+		else tmax.y = (amax.y-p.y)*div.y;
+		if ( div.z < 0 ) tmax.z = (amin.z-p.z)*div.z;
+		else tmax.z = (amax.z-p.z)*div.z;
+		return level.Vec3Offset(p,min(min(tmax.x,tmax.y),tmax.z)*d);
+	}
+
 	// Liang-Barsky line clipping
 	static clearscope bool, Vector2, Vector2 LiangBarsky( Vector2 minclip, Vector2 maxclip, Vector2 v0, Vector2 v1 )
 	{