Valtus Targeting Bug on Vortex Beast

Overview

The purchasable Dreadnought summon ("Valtus") in Siege decides which enemy to attack by scoring every enemy he's aware of as desirability x powerRating-weight and attacks the highest, favoring dangerous enemies out at range.

The reason Valtus typically will not attack the Vortex Beast until all other enemies are eliminated from the map is because the Vortex Beast is stamped powerRating = 1 (fodder level), so Valtus ignores it until almost nothing else is left. Valtus's target picker is set in npc_dreadnought_server.cls:

prop_enemy_processor_mgs -> selectionController (EnemyProcessorControllerSelection)
   -> selectionUtility = UtilityFunctionEnemySelectionByPowerLevel

The controller scores every enemy Valtus is aware of and attacks the highest scorer, re-evaluating continuously. The score is a single multiplication:

score(enemy) = Desirability(enemy) x PowerWeight(enemy)

Desirability = UtilityFunctionDefaultEnemySelection (aggressiveness sub-scores + decision stickiness), roughly 0-1.
PowerWeight = the enemy's powerRating run through a spline, giving 0.1-1.0.

Because it is a product and PowerWeight differs per enemy, the power term re-ranks targets: a dangerous enemy at range can outscore a weak one nearby. It cannot, however, resurrect a target whose desirability is ~0.

Target Desirability

Captioned "Default Selection With Aggressiveness Override" (UtilityFunctionDefaultEnemySelection).
Its core is UtilityFunctionAggressiveness, a weighted average of three sub-scores:

Desirability_core = (5 x Distance + 2 x Busyness + 3 x Offensiveness) / 10

Sub-score (weight)	Input variable	Meaning	Curve
Distance (5)	`FloatValueProviderDistanceToTarget` (meters)	how far the target is	"Decay Closer" `[0,0.1, 80,1]` - see below
Busyness (2)	`FloatValueProviderSumPowerLevelOnTarget` (`ignoreOwner = True`)	combined strength of OTHER attackers already on the target	"Decay With Power Level" `[0,1, 5,0.8, 10,0.8, 30,0.6, 40,0.1]` - crowded target scores lower (spreads AI out)
Offensiveness (3)	`FloatValueProviderRawDmgReceivedFromTarget`	recent damage that enemy dealt to Valtus	"Raise With Damage" `[0,0.1, 20,0.8, 40,1]` - enemies hurting him score higher

The Distance curve (Valtus favors range)

Valtus's recipe overrides the Distance sub-score with a "Decay Closer" spline
[0, 0.1, 80, 1]. On raw meters-to-target:

Distance	Distance sub-score
0 m	0.10 (min)
20 m	0.325
40 m	0.55
60 m	0.775
80 m+	1.00 (max, clamped)

So the closer an enemy is, the lower this sub-score; the farther (out to 80 m), the higher. This fits Valtus as a long-range gatling unit (perfectAttackDistance = 60). Ordinary enemies use the opposite base default in the same file - a "Decay Further" curve [0,1, 7,1, 16,0.8, 40,0.6, 70,0.2] that prefers close targets.

Decision stickiness

Desirability is wrapped in UtilityFunctionDecisionStickiness with StickinessDuration = 7 and StickinessFadeDuration = 3: once Valtus commits to a target, that target keeps a loyalty bonus for 7 s, fading over the next 3 s. This stops frame-to-frame flip-flopping; a much higher-scoring target can still pull him off early.

Enemy PowerWeight

FloatValueProviderTargetPowerLevel reads the target's powerRating (a fixed value per enemy archetype), then a SplineLinear1d with points [0, 0.1, 100, 1] converts it to a multiplier:

PowerWeight = clamp(0.1 + 0.009 x powerRating, 0.1, 1.0)

So powerRating 0 -> 0.10, 1 -> 0.109, 21 -> 0.289, 100+ -> 1.00 (clamped).

Operations reads archetypes_library.sso while Siege merges archetypes_library_hordemode.sso overrides on top. In the tables below, a - in the Siege PR column means the Siege library declares no powerRating for that archetype, so the base value carries through. It does NOT necessarily mean the archetype is absent from the Siege library, several entries there exist only to swap in a _hordemode_ actor class and set no stats at all (the Vortex Beast is one).

powerRating is a separate axis from threatClass (tier): the Vortex Beast is threatClass = BOSS but powerRating = 1. Tier drives HP/damage difficulty scaling; powerRating drives AI target priority (and likely spawn-budget cost).

Tyranids

Enemy	Tier	Base PR	Siege PR	Ops weight	Siege weight
Hormagaunt / Sergeant	FODDER	1	-	0.109	0.109
Termagant	COMMON	2	-	0.118	0.118
Spore Mine / Acid Mine	COMMON	2	-	0.118	0.118
Gargoyle	(unset)	~0	-	0.10	0.10
Tyranid Warrior (all 5 variants)	ELITE	18	-	0.262	0.262
Zoanthrope	SPECIAL	20	-	0.280	0.280
Ravener / Lictor / Biovore	SPECIAL	30	-	0.370	0.370
Lictor Alpha (`TyrLictorBoss`)	MINIBOSS	50	-	0.550	0.550
Neurothrope	MINIBOSS	150	100	1.00	1.00
Carnifex	MINIBOSS	150	100	1.00	1.00

Chaos (Thousand Sons)

Enemy	Tier	Base PR	Siege PR	Ops weight	Siege weight
Cultist / Cultist Sniper	FODDER	1	-	0.109	0.109
Tzaangor	COMMON	5	2	0.145	0.118
Tzaangor Shieldless	COMMON	5	1	0.145	0.109
Tzaangor Gunner	(unset tier)	5	-	0.145	0.145
Tzaangor Spearman	ELITE	18	-	0.262	0.262
Rubric Marine	ELITE	18	21	0.262	0.289
Rubric Marine Flamer	ELITE	25	-	0.325	0.325
Chaos Spawn	ELITE	21	-	0.289	0.289
Occult Terminator (Melee/Ranged)	SPECIAL	30	-	0.370	0.370
Lesser Sorcerer	SPECIAL	30	20	0.370	0.280
Helbrute	MINIBOSS	150	100	1.00	1.00
Terminator Sorcerer (P14)	MINIBOSS	100	-	1.00	1.00
Terminator Sorcerer - Clone (Simple)	MINIBOSS	1	-	0.109	0.109
Terminator Sorcerer - Clone (Complex)	MINIBOSS	30	-	0.370	0.370
Terminator Sorcerer - Clone (Simple Mirror)	(unregistered)	~0 (unset)	-	0.10	0.10
Heldrake	BOSS	~0 (unset)	-	0.10	0.10
Vortex Beast	BOSS	1	-	0.109	0.109

Game Files

ssl/characters/imperium/dreadnought/npc_dreadnought_server.cls
ssl/characters/imperium/dreadnought/npc_dreadnought_hordemode_server.cls
ssl/ai/enemy_selection/advanced_enemy_selection/utility/utility_function_enemy_selection_by_power_level.sso
ssl/ai/enemy_selection/advanced_enemy_selection/utility/utility_function_aggressiveness.sso
ssl/spawn_system/archetypes/archetypes_library.sso
ssl/spawn_system/archetypes/archetypes_library_hordemode.sso