Implement subterranean units.

mods/ts/rules/nod-vehicles.yaml

@@ -291,12 +291,21 @@ SAPC:
 		TurnSpeed: 5
 		Speed: 71
 		RequiresCondition: !empdisable && !loading
+		Subterranean: true
+		SubterraneanCondition: submerged
+		SubterraneanTransitionTerrainTypes: Clear, Rough
+		SubterraneanTransitionCost: 120
+		SubterraneanTransitionSound: subdril1.aud
+		SubterraneanTransitionImage: dig
+		SubterraneanTransitionSequence: idle
+		TerrainSpeeds:
+			Subterranean: 120
 	Health:
 		HP: 175
 	Armor:
 		Type: Heavy
 	RevealsShroud:
-		RequiresCondition: !inside-tunnel
+		RequiresCondition: !inside-tunnel && !submerged
 		Range: 5c0
 		MaxHeightDelta: 3
 	Cargo:
@@ -306,6 +315,10 @@ SAPC:
 		UnloadVoice: Unload
 		LoadingCondition: loading
 		EjectOnDeath: true
+	WithVoxelBody:
+		RequiresCondition: !submerged
+	Targetable:
+		RequiresCondition: !inside-tunnel && !submerged
 
 SUBTANK:
 	Inherits: ^Tank
@@ -324,12 +337,21 @@ SUBTANK:
 		TurnSpeed: 6
 		Speed: 71
 		Crushes: wall, crate, infantry
+		Subterranean: true
+		SubterraneanCondition: submerged
+		SubterraneanTransitionTerrainTypes: Clear, Rough
+		SubterraneanTransitionCost: 120
+		SubterraneanTransitionSound: subdril1.aud
+		SubterraneanTransitionImage: dig
+		SubterraneanTransitionSequence: idle
+		TerrainSpeeds:
+			Subterranean: 120
 	Health:
 		HP: 300
 	Armor:
 		Type: Light
 	RevealsShroud:
-		RequiresCondition: !inside-tunnel
+		RequiresCondition: !inside-tunnel && !submerged
 		Range: 5c0
 		MaxHeightDelta: 3
 	Armament:
@@ -337,6 +359,10 @@ SUBTANK:
 	AttackFrontal:
 		Voice: Attack
 	AutoTarget:
+	WithVoxelBody:
+		RequiresCondition: !submerged
+	Targetable:
+		RequiresCondition: !inside-tunnel && !submerged
 
 STNK:
 	Inherits: ^Tank

mods/ts/rules/world.yaml

@@ -60,6 +60,7 @@
 	TerrainGeometryOverlay:
 	ExitsDebugOverlayManager:
 	CliffBackImpassabilityLayer:
+	SubterraneanActorLayer:
 
 World:
 	Inherits: ^BaseWorld