NPCs do not collect the weapon after defeating an opponent

[szapp]

Describe the bug
NPCs do not reliably pick up the weapon of their defeated opponent.

Expected behavior
NPCs now correctly pick up the weapon and ammunition of their defeated opponent.

Steps to reproduce the issue

1. Attack an NPC.
2. Get defeated by the NPC in a fight.
3. The NPC might loot the ore of the PC but not will fail to pick up the weapon.

[szapp]

Thanks for your contributions! It looks like you chose the wrong issue template (for language/translations bugs). I will try to add the missing details.

It looks like the following function is involved. The item cannot be reliably determined and no weapon will be picked up as a result. It is very similar to #3.

gothic-1-community-patch/scriptbase/_work/Data/Scripts/Content/AI/B_Human/B_AssessBody.d

Lines 110 to 130 in 04830dc

	func void ZS_AssessBody_RecoverWeapon ()
	{
	PrintDebugNpc (PD_ZS_FRAME, "ZS_AssessBody_RecoverWeapon");
	B_SetPerception (self);
	//-------- nach der evtl. fallengelassenen Waffe suchen --------
	Npc_PerceiveAll (self);
	if (( Wld_DetectItem (self,ITEM_KAT_NF) || Wld_DetectItem (self,ITEM_KAT_FF) )
	&& Npc_GetDistToItem(self,item) < 300 )
	{
	PrintDebugNpc (PD_ZS_CHECK, "...Nah- oder Fernkampfwaffe gefunden!" );
	B_SayOverlay (self, NULL, "$ITakeYourWeapon");
	AI_TakeItem (self, item);
	AI_EquipBestMeleeWeapon(self);
	AI_EquipBestRangedWeapon(self);
	};
	//-------- Heilen ! --------
	AI_StartState (self, ZS_HealSelf, 1, "");
	};

The if-condition here is faulty. Both function calls to Wld_DetectItem set the instance item - if not found it will be set to NULL. Therefore it may happen that the condition will not be true. To solve this, it should be confirmed that the byte code of the if-condition looks like here. The if-block should be overwritten with something similar as found here already (with adjusted distance and the additional SVM output):

gothic-1-community-patch/src/Ninja/G1CP/Content/Fixes/Session/fix003_RegainDroppedWeapon.d

Lines 32 to 70 in 1d4b915

	/*
	* This function essentially replaces (not technically!) the function 'B_RegainDroppedWeapon'
	*/
	func void G1CP_003_RegainDroppedWeapon_Logic(var C_Npc slf) {
	Npc_PerceiveAll(slf);
	// Define possibly missing symbols locally
	const int ITEM_KAT_NF = 1<<1;
	const int ITEM_KAT_FF = 1<<2;
	const int ITEM_KAT_MUN = 1<<3;
	// Melee weapon
	if (Wld_DetectItem(slf, ITEM_KAT_NF)) {
	if (Npc_GetDistToItem(slf, item) < 300) // Prevent walking off too far
	&& (G1CP_NpcCanSeeItemFreeLos(slf, item)) // Does not have to face it, only line of sight
	&& (!Npc_HasEquippedMeleeWeapon(slf)) {
	AI_TakeItem(slf, item);
	AI_Function_NI(slf, EquipWeapon, slf, Hlp_GetInstanceId(item)); // Equip this exact weapon in particular
	};
	};
	// Ranged weapon
	if (Wld_DetectItem(slf, ITEM_KAT_FF)) {
	if (Npc_GetDistToItem(slf, item) < 300)
	&& (G1CP_NpcCanSeeItemFreeLos(slf, item))
	&& (!Npc_HasEquippedRangedWeapon(slf)) {
	AI_TakeItem(slf, item);
	AI_Function_NI(slf, EquipWeapon, slf, Hlp_GetInstanceId(item));
	};
	};
	// Ammunition (just a bonus)
	if (Wld_DetectItem(slf, ITEM_KAT_MUN)) {
	if (Npc_GetDistToItem(slf, item) < 300)
	&& (G1CP_NpcCanSeeItemFreeLos(slf, item)) {
	AI_TakeItem(slf, item);
	};
	};
	};

[pawbuj1981]

Here is main condition for that code from my resources,

Maybe it helps to decrease level of incompaitibility !!

if ( Wld_DetectItem (self, ITEM_KAT_NF) 
	{
		**if (Hlp_IsValidItem(item))// this "if" is really new thing !!!**
		{
			if (Npc_GetDistToItem(self,item) < 1000)
			{				
				AI_GotoItem				(self, item);				
				AI_TakeItem	(self, item);				
				B_Say		(self, self, "$ITAKEYOURWEAPON");	

[szapp]

Suggestion on how to implement it:

1. Find the if condition in the byte code. Identify it by the function calls to Wld_DetectItem and Npc_GetDistToItem and the conjunctions || and &&, arguments can be neglected.
   

   gothic-1-community-patch/scriptbase/_work/Data/Scripts/Content/AI/B_Human/B_AssessBody.d

   Lines 116 to 120 in 04830dc

   	//-------- nach der evtl. fallengelassenen Waffe suchen --------
   	Npc_PerceiveAll (self);
   	if (( Wld_DetectItem (self,ITEM_KAT_NF) || Wld_DetectItem (self,ITEM_KAT_FF) )
   	&& Npc_GetDistToItem(self,item) < 300 )
   	{

2. Use the G1CP function G1CP_AddIfCondition to check the evaluation of the conditions. This is done by passing a function to G1CP_AddIfCondition that takes one parameter. If that argument is true in our function, properly set the global symbol item by re-running Wld_DetectItem (separately! for ITEM_KAT_NF and ITEM_KAT_FF) and return true to continue into the if-block.
3. Additionally, the function calls to AI_EquipBestMeleeWeapon and AI_EquipBestRangedWeapon could be replaced to equip explicitly the picked up weapon - given it is stronger than the currently equipped one. This will prevent traders from then suddenly equipping a completely different weapon from their trading inventory, see Vendors equip strongest weapon  #59.

[szapp]

The test is semi-automatic. It is manual, but the success will be displayed on the screen. Failure will be visible from the zSpy.