From Bohemia Interactive Community
Revision as of 22:55, 29 March 2018 by Lou Montana (talk | contribs) (Remove note about a possible .lip bug, apparently my mistake (still investigating))
Jump to navigation Jump to search

Logo A2.png1.00


Conversations are a system introduced with Arma 2 and created to enhance discussions. This system allows dynamic conversations and a more fluid sentence/answer flow.

Its main advantages are:

  • The system itself waits for the sound sample to finish. No more sample time measuring and countless sleeps!
  • Conversation always flows through the appropriate channel (direct for face to face, team radio for distant team members etc.)
  • Possibility to create fully dynamic conversations
  • Transparent syntax (FSM branches allow fast and efficient edits)


  • A topic is defined by a String for id and sentences defined in a Conversation .bikb file
  • A Conversation .bikb lists all available sentences in a topic
  • A topic must be added to the concerned units, with eventually a Conversation FSM and/or a Conversation Event Handler
  • A Conversation FSM defines an AI unit reaction to a sentence
  • A Conversation Event Handler defines a player's unit reaction to a sentence, potentially defining available answers
  • If the unit is playable (can be either player or AI), both should be present to ensure a proper reaction in every encountered scenario.


A conversation topic

  1. must be added to units (via kbAddTopic)
  2. for the units to be able use it (via kbTell for example)
  3. once the unit said wanted sentences (checked via kbWasSaid),
  4. the topic can be removed (via kbRemoveTopic).

Manual conversation example

miles   kbAddTopic ["briefing", "kb\briefing.bikb"];
shaftoe kbAddTopic ["briefing", "kb\briefing.bikb"];

shaftoe kbTell [miles, "briefing", "shaftoe_briefing_H_1"];
waitUntil { shaftoe kbWasSaid [miles, "briefing", "shaftoe_briefing_H_1", 3]; };

miles kbTell [shaftoe, "briefing", "shaftoe_briefing_M_1"];
waitUntil { miles kbWasSaid [shaftoe, "briefing", "shaftoe_briefing_M_1", 3]; };

hint "Conversation ended.";
// you could use kbRemoveTopic here to "clear" the units if the topic is not required anymore. This is not mandatory.

Conversation .bikb

.bikb extension stands for "Bohemia Interactive Knowledge Base" as it was originally used only for storing an AI unit's memory of what it has seen.
This file declares the available sentences in the topic, their sound samples and the corresponding subtitles (see example 1 and example 2).

Sounds don't need to be defined in CfgSounds or CfgRadio unless you want to use them with e.g playSound, say or groupRadio.
As opposed to these commands, this new conversation system will automatically use setRandomLip during the speech if no .lip file is present. A .lip file can however still be used for a more precise animation.

"Interrupted" event

The left-side conversation menu (with the list of possible sentences) can be closed via backspace at all times. If you want to handle this event as well, you have to add new sentence class called Interrupted into your .bikb file. It can then be used as a standard _sentenceId in the script.

.bikb simple example

class Sentences
	class hello1
		text = "Hello!";					// sentence subtitle - can be "text" or $STR_ stringtable reference
		speech[] = { "\Sound\hello1.ogg" };	// sound file path relative to mission or campaign directory
		class Arguments {};					// unused here
	class hi_how_are_you
		text = "Hi, how are you?";
		speech[] = { "\Sound\hi_how_are_you.ogg" };
		class Arguments {};
	class good_you
		text = $STR_GoodYou; // has to start with "STR_"!
		speech[] = { "\Sound\good_you.ogg" };
		class Arguments {};
	class fine_thanks
		text = $STR_FineThanks;
		speech[] = { "\Sound\fine_thanks" }; // no extension means .wss to the engine
		class Arguments {};

	// these sentences are here to be a full example for later Conversation Event Handler example
	class what_do_we_do { text = "What do we do today?"; speech[] = { "\Sound\wdwd.ogg" }; class Arguments {}; };
	class choose_football { text = "Let's football!"; speech[] = { "\Sound\cf.ogg" }; class Arguments {}; };
	class choose_bike { text = "Let's bike?"; speech[] = { "\Sound\cb.ogg" }; class Arguments {}; };
	class choose_arma2 { text = "I know! Arma 2"; speech[] = { "\Sound\ca.ogg" }; class Arguments {}; };

	// the Interrupted sentence triggered when the conversation menu is closed without answering (e.g using backspace)
	class Interrupted
		text = "Hey, come back!";
		speech[] = { "\Sound\interrupted.ogg" };
		class Arguments {};

// Don't worry about these.
class Arguments {};
class Special {};
startWithVocal[] = { hour };
startWithConsonant[] = { europe, university };

.bikb advanced example

See Words configuration and below for more details.

class Sentences
	class AirstrikeRequest 
		text = "%team requesting close air support at grid %location ";

		// available words are defined in config > RadioProtocol > Words
		speech[] = { %Team, RequestingCloseAirSupportAtGrid, %Location };

		class Arguments 
			class Team { type = "simple"; };
			class Location { type = "simple"; };

class Arguments {};
class Special {};
startWithVocal[] = { hour };
startWithConsonant[] = { europe, university };

Conversation FSM

As stated earlier, the Conversation FSM fires on sentence received by an AI and defines AI unit's reaction. The Conversation FSM receives the following arguments:

  • _this: Object - receiver or listener of the sentence. One of the units that had this particular script assigned via kbAddTopic
  • _from: Object - the unit that told the sentence
  • _sentenceId: String - the sentence this unit is reacting to. Defined in .bikb in class Sentences
  • _topic: String - topic name used in kbAddTopic

See also: FSM, FSM Editor

Conversation FSM example


Conversation Event Handler

The Conversation Event Handler is not an Event Handler as we know them. It is Code that will be executed with each sentence received by a player, and will constantly fire (onEachFrame) when the player is pointing at a "talkable" person at "talkable" range. Following parameters are passed:

  • _this: Object - the player receiving the sentence. Must have had this particular script assigned via kbAddTopic
  • _from: Object - the unit that told the sentence
  • _sentenceId: String - the sentence this unit is reacting to. Defined in .bikb in class Sentences
  • _topic: String - topic name used in kbAddTopic

Conversation Event Handler example

// here we will be storing all the sentences from which the player will choose (the menu on the left side of the screen)
// if there is only one option in the array, the sentence will replace the "Talk to" action name

 BIS_convMenu = [];

// we want the player to be able to approach his buddy and talk to him via the action menu.
// we need to check:
// if the player is pointing at his buddy
// if the player is not answering any of his buddy's sentences
// if the player hasn't told him hello already
// then we add that array to BIS_convMenu - the parameters are mostly self-explanatory:

if (_from == buddy1 && _sentenceId == "" && !(_this kbWasSaid [_from, _topic, "hello1", 999999])) then
	BIS_convMenu = BIS_convMenu + [["Say hello.", _topic, "hello1", []]];

// here we make the unit say the proper sentence based on the one he just received
// switch-case-do is used here but it is completely up to you how to evaluate it (if-then etc.)
switch (_sentenceId) do
	case "hello1":
		_this kbTell [_from, _topic, "hi_how_are_you"];
	case "good_you":
		_this kbTell [_from, _topic, "fine_thanks"];
	case "what_do_we_do": {
		// the player will have 3 answers to choose from:
		BIS_convMenu = BIS_convMenu + [["Football.", _topic, "choose_football", []]];
		BIS_convMenu = BIS_convMenu + [["Bike.", _topic, "choose_bike", []]];
		BIS_convMenu = BIS_convMenu + [["Arma II.", _topic, "choose_arma2", []]]

// return the sentence list pool

See also