diff --git a/OpenRA.Game/OpenRA.Game.csproj b/OpenRA.Game/OpenRA.Game.csproj
index 17c38c8d4f..6cf57e3eda 100755
--- a/OpenRA.Game/OpenRA.Game.csproj
+++ b/OpenRA.Game/OpenRA.Game.csproj
@@ -82,7 +82,7 @@
     <Compile Include="Orders\GenericSelectTarget.cs" />
     <Compile Include="Traits\AI\EmitInfantryOnSell.cs" />
     <Compile Include="Traits\AI\ReturnOnIdle.cs" />
-    <Compile Include="Traits\HasSight.cs" />
+    <Compile Include="Traits\RevealsShroud.cs" />
     <Compile Include="Traits\Player\VictoryConditions.cs" />
     <Compile Include="Traits\Modifiers\HiddenUnderFog.cs" />
     <Compile Include="Traits\Render\RenderFlare.cs" />
diff --git a/OpenRA.Game/Traits/Mobile.cs b/OpenRA.Game/Traits/Mobile.cs
index 86d5d92195..165016362a 100644
--- a/OpenRA.Game/Traits/Mobile.cs
+++ b/OpenRA.Game/Traits/Mobile.cs
@@ -53,7 +53,6 @@ namespace OpenRA.Traits
 				{
 					self.World.WorldActor.traits.Get<UnitInfluence>().Remove(self, this);
 					self.Location = value;
-					self.World.WorldActor.traits.Get<Shroud>().UpdateActor(self);
 				}
 				self.World.WorldActor.traits.Get<UnitInfluence>().Add(self, this);
 			}
diff --git a/OpenRA.Game/Traits/HasSight.cs b/OpenRA.Game/Traits/RevealsShroud.cs
similarity index 79%
rename from OpenRA.Game/Traits/HasSight.cs
rename to OpenRA.Game/Traits/RevealsShroud.cs
index b463f1a397..642544a6a2 100644
--- a/OpenRA.Game/Traits/HasSight.cs
+++ b/OpenRA.Game/Traits/RevealsShroud.cs
@@ -20,16 +20,19 @@
 
 namespace OpenRA.Traits
 {
-	class HasSightInfo : TraitInfo<HasSight> { }
+	class RevealsShroudInfo : TraitInfo<RevealsShroud> { }
 
-	// for random non-mobile movers
-
-	class HasSight : ITick
+	class RevealsShroud : ITick
 	{
+		int2 previousLocation;
+
 		public void Tick(Actor self)
 		{
-			if (!self.IsIdle)
+			if (!self.IsIdle && previousLocation != self.Location)
+			{
+				previousLocation = self.Location;
 				self.World.WorldActor.traits.Get<Shroud>().UpdateActor(self);
+			}
 		}
 	}
 }
diff --git a/OpenRA.Game/Traits/World/Shroud.cs b/OpenRA.Game/Traits/World/Shroud.cs
index 8d6f0df3e2..51ec67cf28 100644
--- a/OpenRA.Game/Traits/World/Shroud.cs
+++ b/OpenRA.Game/Traits/World/Shroud.cs
@@ -87,6 +87,8 @@ namespace OpenRA.Traits
 				vis = GetVisOrigins(a).ToArray()
 			};
 
+			if (v.range == 0) return;		// don't bother for things that can't see
+
 			foreach (var p in v.vis)
 			{
 				foreach (var q in FindVisibleTiles(a.World, p, v.range))
diff --git a/mods/cnc/defaults.yaml b/mods/cnc/defaults.yaml
index 07a709a1a7..60f5ac9d22 100644
--- a/mods/cnc/defaults.yaml
+++ b/mods/cnc/defaults.yaml
@@ -11,6 +11,7 @@
 	Passenger: 
 	IronCurtainable: 
 	HiddenUnderFog:
+	RevealsShroud:
 
 ^Infantry:
 	Category: Infantry
@@ -26,6 +27,7 @@
 	Passenger:
 	HiddenUnderFog:
 	PoisonedByTiberium:
+	RevealsShroud:
 
 ^Ship:
 	Category: Ship
@@ -34,12 +36,14 @@
 		MovementType: Float
 	Selectable:
 	HiddenUnderFog:
+	RevealsShroud:
 
 ^Plane:
 	Category: Plane
 	Unit:
 	Selectable:
 	HiddenUnderFog:
+	RevealsShroud:
 
 ^Building:
 	Category: Building
diff --git a/mods/cnc/vehicles.yaml b/mods/cnc/vehicles.yaml
index 7652e579c2..5aecbb3abf 100644
--- a/mods/cnc/vehicles.yaml
+++ b/mods/cnc/vehicles.yaml
@@ -379,7 +379,7 @@ TRAN:
 		Armor: light
 		InitialFacing: 20
 		ROT: 5
-		Sight: 0
+		Sight: 4
 		Speed: 15
 	Helicopter:
 	RenderUnitRotor:
@@ -407,7 +407,7 @@ HELI:
 		Crewed: yes
 		InitialFacing: 20
 		ROT: 4
-		Sight: 0
+		Sight: 6
 		Speed: 20
 	AttackHeli:
 		PrimaryWeapon: HighV
@@ -438,7 +438,7 @@ ORCA:
 		Crewed: yes
 		InitialFacing: 20
 		ROT: 4
-		Sight: 0
+		Sight: 6
 		Speed: 20
 	AttackHeli:
 		PrimaryWeapon: Rockets
diff --git a/mods/ra/defaults.yaml b/mods/ra/defaults.yaml
index 9c39313834..6e35172fe6 100644
--- a/mods/ra/defaults.yaml
+++ b/mods/ra/defaults.yaml
@@ -11,6 +11,7 @@
 	Passenger: 
 	IronCurtainable: 
 	HiddenUnderFog:
+	RevealsShroud:
 
 ^Infantry:
 	Category: Infantry
@@ -25,6 +26,7 @@
 	AutoTarget:
 	Passenger:
 	HiddenUnderFog:
+	RevealsShroud:
 
 ^Ship:
 	Category: Ship
@@ -33,6 +35,7 @@
 		MovementType: Float
 	Selectable:
 	HiddenUnderFog:
+	RevealsShroud:
 
 ^Plane:
 	Category: Plane
@@ -40,6 +43,7 @@
 		TargetType: Air
 	Selectable:
 	HiddenUnderFog:
+	RevealsShroud:
 
 ^Building:
 	Category: Building
diff --git a/mods/ra/vehicles.yaml b/mods/ra/vehicles.yaml
index 667d1d432e..e410e9f148 100644
--- a/mods/ra/vehicles.yaml
+++ b/mods/ra/vehicles.yaml
@@ -560,7 +560,6 @@ MIG:
 		Ammo: 3
 	IronCurtainable:
 	ReturnOnIdle:
-	HasSight:
 
 YAK:
 	Inherits: ^Plane
@@ -590,7 +589,6 @@ YAK:
 		Ammo: 15
 	IronCurtainable:
 	ReturnOnIdle:
-	HasSight:
 
 TRAN:
 	Inherits: ^Plane
@@ -618,7 +616,6 @@ TRAN:
 		PassengerTypes: Foot
 		Passengers: 5
 	IronCurtainable:
-	HasSight:
 
 HELI:
 	Inherits: ^Plane
@@ -650,7 +647,6 @@ HELI:
 	LimitedAmmo:
 		Ammo: 6
 	IronCurtainable:
-	HasSight:
 
 HIND:
 	Inherits: ^Plane
@@ -680,7 +676,6 @@ HIND:
 	LimitedAmmo:
 		Ammo: 12
 	IronCurtainable:
-	HasSight:
 
 U2:
 	Inherits: ^Plane