Behavior Operations

A “Behavior” in NPCClient is a script defined in npcbehave.xml to run to make the npc behave a certain way. It is almost like a state, for AI designers used to state machine npcs. Example behaviors might include “guard patrol”, “wander in forest”, “fight attackers”, “smith an item”. Before we talk about how everything fits together we will go over what is possible in npcclient with these detailed behavior scripts. The following is a list and reference description of each behavior script operation or command you can use. They are put together in sequences called beaviors as will be described later in Behaviors_and_Reactions.

Assess Operation

(Net load: 1, CPU Load 1)

Parameter	Type	Default	Description
physical	string		The prefix for the physical perception.
magical	string		The prefix for the magical perception.
overall	string		The perfix for the overall perception.

Each of the physical, magical, or overall will be assessed as; "lame", "weaker", "equal", "stronger", or "powerfull".

 Ex: <assess overall="$target overall" />

Typical reaction to catch the response to this would be as shown in the example below. $target is used here to make sure the correct assessment is matched to the same target. A npc will not react if the target has changed before the response is received.

 Ex: <react event="$target overall equal" .../>
     <react event="$target overall weaker" .../>

Chase Operation

(Net load: 3, CPU Load 3)

Parameter	Type	Default	Description
anim	string		The animation to use for the chase.
type	nearest_actor,nearest_npc,nearest_player,owner,target		nearest_* is the neares entity of that type. target is current target.
range	float	2.0	The range to search for target of the chase.
chase_range	float	-1	The range at where the chase should give up and issue a "<target> out of chase" perception. -1 is default to disable the max range check.
offset	float	0.5	The distance to stop before the target of the chase. See Offset for more details.
offset_angle	float	0.0	Size of the arc used to distribute the chase when aproching the target. The angle is in degrees.
vel	float,$WALK,$RUN	Default is to use the velocity from the behavior.	The velocity to use when chasing.
ang_vel	float		0 is to use the default from the behavior.
collision	string	collision	The name of the perception to be used when a collision perception is to be fired.
out_of_bounds	string	out of bounds	The name of the perception to be used when a out of bounds perception is to be fired.
in_bounds	string	in bounds	The name of the perception to be used when a in bound perception is to be fired.

Chasing a player is one example where both turning and moving at the same time are required to give a realistic effect to the behavior. We have <move> and <rotate> but this one does them together and intelligently to follow a targeted player or entity. Normally, this will be used to get npc’s to chase after players if players run away during a fight.

 Ex: <chase type="enemy" anim="walk" range=”2” />

In this example, the npc will play the animation called “walk” while moving and turning as appropriate to reduce his range to his most hated enemy. Of course, he is limited by his speed and if the player can run faster than he can chase, he will never catch the player. An "<target> out of chase" perception will be fired in this case.

The “type” attribute of the operation can be either “enemy” as shown here, “owner” to follow the NPC’s owner around, or “nearest” to chase after the nearest player at the time the operation was initiated. This operation will continue until interrupted by another behavior or until the distance to the target from the npc is less than the range specified. (2 is the default if no range is specified.) This operation sends DR messages whenever it turns or changes course, plus the DR messages to start the forward motion and animation, and to stop them. The CPU load is somewhat heavy because CD must be performed as the npc is chasing, since his path is not predetermined.

Circle Operation

(Net load: 3, CPU Load: 2)

Parameter	Type	Default	Description
anim	string		The animation to use for the operation.
radius	float	Mandatory, no default value	Radius to move NPC around with.
angle	float	2PI	The angle to move. Calculated if 0 and duration not 0.
duration	float	0	The duration to move in circle. Calculated if 0.
ang_vel	float		The angular velocity to use when moving in the circle. Calculated if 0.

Moving the NPC around in a circle. The following example will move the npc around using the velocity defined in the behavior in one complete circle in 10 sec.

 Ex: <circle anim="walk" radius=”2” duration="10" />

Debug Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
level	int	Mandatory	The level of debug to turn on for current NPC.
exclusive	string		Will set on exclusive logging for this NPC.

Turn on and of debug printouts on the server console. Used for debuging of script operations. Level 1-4 Only the biggest events, 5-9 Medium number of events, 10-15 and more is maximum output.

 Ex: <debug level=”2” />

Dequip Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
slot	string	Mandatory	The slot to dequip an move back into inventory.

Dequip an item held by the NPC in the given slot.

 Ex: <dequip slot="righthand" />

Dig Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
resource	string,tribe:wealth	Mandatory	Resource to dig for or by using the keyword tribe:wealth look up in the tribe to find the resource

Order an NPC to start digging for a resource. The keyword "tribe:wealth" will cause the resource to be looked up in the wealth_resource_nic field in the tribes table if the NPC is part of a tribe.

 Ex: <dig resource="tribe:wealth" />
     <dig resource="Gold Ore" />

Drop Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
slot	string	Mandatory	The slot from which the item is to be dropped.

This operation allows an NPC to drop an item he has in inventory on the ground.

 Ex: <drop slot="lefthand" />

Eat Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
resource	string,tribe:wealth	Mandatory	The resource to reward the tribe when eating.

Simple simulation that the tribe would gain things like flesh from eating at a dead entity withing a range of 1.0. The tribe wealth resource would be read from the wealt_resource_name field in the tribes table.

 Ex: <eat resource="tribe:wealth" />
     <eat resource="Flesh" />

Emote Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
cmd	string		The emote cmd to be used as defined in the emote.xml file. Including leading /.

This operation allows an NPC to do an emotion.

 Ex: <emote cmd="/greet" />

Equip Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
item	string	Mandatory	The name of the item to equip
slot	string	Mandatory	The sloot to dquip the item in
count	int	1	The number of items to equip. Will be forced to at least 1.

Equip one item from inventory into the given slot.

 Ex: <equip item="Sword" slot="righthand" count="1" />

Invisible Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description

No parameters.

This operation makes the NPC invisible through the toggle visibility command. See Visible Operation.

 Ex: <invisible />

Locate Operation

(Net load: 0, CPU Load 0)

Parameter	Type	Default	Description
obj	See table below.	Mandatory	The object to locate
failure	string		A perception to fire if fails to locate the given obj.
static	boolean	false	For location the search could be made static. Se description for more details.
range	float	-1	The maximum range to locate within. -1 represents infinite.
random	boolean	false	If true a random return within the radius will be made. Otherwise the nearest entry will be returned.
invisible	boolean	false	Set this to true if the locate operation should consider invisible objects
invincible	boolean	false	Set this to true if the locate operation should consider invincible objects.

Obj can be one of the following:

obj	Description
string	Locate a location. This is the default if none of the following obj types is matched.
perception	The location of the last received perception.
target	Locate a target
owner	Locate the owner, if this NPC is owned (Pets and stuff)
point	Random point
region	Locate a random point within the region of the NPC.
self	Locate your self
spawn	Spawn location of the npc.
tribe:home	Locate the npcs tribe home place.
tribe:memory:string	Locate something from the Tribes memory. See the ShareMemories and Memorize operation.
tribe:resource	Locate a resource location from the memory of the tribe.
friend	Locate a friend.
waypoint	Will locate a waypoint.
waypoint:group:string	Locate a waypoint from a given group
waypoint:name:string	Locate a waypoint by name.

This operation is one of the more flexible and crucial operations in npc scripting. It allows the scripter to have his npc “find” a certain thing or type of thing, and remember that location for other scripting commands later such as turning, moving or attacking. The operation will store the position found in the NPCs as active postion and calcualte the neares waypoint and store that in the active_waypoint. For location it is possible to make the first search a static search. So that the first time the npc do this operation it could search for a "Baker" location. The next time the operation is used it will use the results of the first time even if there might be Bakers closer at that time.

 Ex: <locate obj="perception" />
     <locate obj="enemy" />
     <locate obj="furnace" range="50" />
     <locate obj="waypoint" failure="no waypoint found" />

Example 1 finds the last perception received by the current npc and sets the active target location to the location of that perception. This allows npcs who receive “Talk” perceptions to turn to face the person talking to them. It allows npcs who have a spell cast on them to turn to face the caster, and so on.

Example 2 finds the location of the currently active “enemy” of the NPC, which is the entity with the highest score on the NPC’s hate list, and sets that location as the active target location for other operations. This allows NPCs to turn to face the person they are attacking, chase attackers who are retreating, etc.

Example 3 uses predefined lists of named location types to find the closest one to the npc and sets the active target location to the coordinates specified there. This is the most subtle of the 3, and in some ways the most powerful so it deserves more discussion. Consider the following pictures:

Here we have two blacksmith shops with similar items but different layouts. They might be side by side or they might be in entirely different cities. LocTypes specify a list of Anvil locations, or a list of Furnace locations, as marked by the stars on these pictures. When Example 3 says to locate the nearest furnace, an NPC in smithy #1 will find his furnace while the NPC in smithy #2 will find his own furnace. They will be able to share one script for moving between these points and acting like a real blacksmith in their own location, even though they are in totally different smithy shops.

This will become even more important when we implement player housing and player shops. It will be possible with the scripts we have already today for a player to build the blacksmith shop of his own design and for him to hire an npc smith to come work in that shop. The Smith NPC he hired will be able to “know” how to get around the player’s shop magically.

Something intended to be supported here but not actually implemented yet was the ability to locate named objects or entities as well, so an NPC could locate a sword someone dropped on the ground and things like this. Better integration with the entity system and perhaps integration with data from the maps themselves rather than externally generated lists of points could make this even more powerful.

Loop Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
iterations	int	0	Number of iterations to do in this loop.

This operation allows you to loop a section of your script a certain number of times. This is mostly useful for city npcs such as smiths and tavern barkeeps. Behaviors in general will loop if not replaced by another behavior, but if you want subloops within the script, this is an easy way to do it.

Ex:

 <loop iterations="20">
   <locate obj="fire" range="10" />
   <navigate anim="walk" />
   <wait anim="stand" duration="30" />
   <locate obj="anvil" range="10" />
   <navigate anim="walk" />
   <wait anim="hammer" duration="20" />
 </loop>

In this example, the blacksmith is scripted to walk back and forth between his fire and his anvil 20 times before moving on to the next operation in his script to act like a blacksmith.

This operation does not affect the network at all and does not have CPU overhead.

Melee Operation

(Net load: 1, CPU Load: 2)

Parameter	Description
seek_range	float	0.0	The range to search for new targets in melee
melee_range	float[0.5-3.0]	3.0	The range where melee can be done. Max 3.0 to prevent npc/server conflicts.
stance	string	normal	The stance to use when attacking.
invisible	boolean	false	Will melee operation fight invisible entities
invincible	boolean	false	Will melee operation fight invincible entities.

The <melee> operation handles starting and ending fights for the NPC. It finds the most hated enemy in range and tells the server to attack him. If there is no enemy in range, it finds the nearest enemy that it does hate and prepares to chase him.

 Ex: <melee seek_range="10" melee_range="3" />

The “melee_range” attribute specifies how far away the enemies can be while still fighting without the npc needing to move. 3 meters is the maximum of how far away a player can be to hit the npc also, so in most cases this is a good value. The “seek_range” specifies how far around himself the npc should look for other enemies if none are found within the melee_range. If there are no enemies within the seek_range, the npc starts to calm down and his current behavior (making his ‘melee’ operation active) is lowered in priority. If an enemy is found within the seek_range, the NPC’s active enemy is set to this found person so the <chase type=”enemy”> operation can run after him.

This operation’s only network load is informing the server of its melee target and attack mode, and switching these occasionally as people die, etc. The CPU load is in periodically (2x per second) checking the hate list for the NPC to make sure the most hated person is being fought. If no one on the hate list is within the melee range, a more expensive operation is done to find any hated people within the seek_range, but this operation isn’t performed very often.

The NPC Hate List is a very important thing for an npc scripter to understand. Each NPC maintains its own list of entities that it does not like, and each of these entities gets a hate score based on what the entity does to the npc. For example, an npc on startup has an empty hate list. But then a player (“Androgos”) attacks him and hits him for 10 damage:

Hatelist: Androgos-10

Now Androgos is the most hated player (because he is the only one) and the npc chooses to fight him back with his <melee> operation. A few seconds later in the fight, Androgos hits him again for 12 damage and Androgos’s friend “Gronomist” casts a Fire spell on the npc also, for 25 damage.

Hatelist: Androgos-22, Gronomist-25

Next time the <melee> operation is checked, Gronomist becomes the most hated person and the npc will switch his attack to focus on Gronomist. Meanwhile, a 3rd player in the group, “Djagg” is the healer of the group and heals Androgos’s wounds for 15 HP, which the NPC really hates.

Hatelist: Androgos-22, Gronomist-25, Djagg-45

So now the NPC decides to go after the healer. And so on. The idea is that the tactics of the NPC can be determined by the way he reacts to different events during combat such as spells, damage and healing. Different reactions can be scripted for different npcs, as we will see in the next section.

When a player dies, they are removed from the hatelist. So the NPC will not recognize the reincarnated player when he comes back. This keeps the entire world from attacking players all the time, and keeps hatelists reasonably short. Likewise, when the NPC dies, his entire hatelist is cleared out.

Memorize Operation

(Net load: 0, CPU Load: 0)

Tribe operation.

Parameter	Type	Default	Description

No Parameters.

This is an operation that only will have effect for tribe members. The NPC will memorize the current perception as a private memory. See the ShareMemories Operation for how to make the memories known to other members of the tribe.

 Ex: <memorize />

Move Operation

(Net load: 0, CPU Load: 5)

Parameter	Type	Default	Description
anim	string		The animation to use when moving.
duration	float	0.0	The duration this move should have. The default is probably no good.
vel	float,$WALK,$RUN	Default is to use the velocity from the behavior.	The velocity to use when moving.
ang_vel	float	0.0	By defining a ang_vel the movement will be much like the Circle Operation.
collision	string	collision	The name of the perception to be used when a collision perception is to be fired.
out_of_bounds	string	out of bounds	The name of the perception to be used when a out of bounds perception is to be fired.
in_bounds	string	in bounds	The name of the perception to be used when a in bound perception is to be fired.

The most basic behavior operation in npcclient is <move>. It simply tells the npc to move forward at a certain speed in the direction he is currently pointing, and to play a named animation while doing so.

 Ex: <move vel="1" anim="walk" />
     <move anim="walk" vel="$WALK" out_of_bounds="move_outside_region" />

This operation has no preset end or duration, so it will go until the behavior is preempted by another higher priority behavior such as the one to turn, triggered by a collision perception. (See the next section for a more detailed explanation of how behaviors pre-empt each other and change priorities.)

This operation has low networking overhead since all it does is trigger a single Dead Reckoning (DR) update to start the forward motion. It does have CPU overhead during the entire duration of it running though, since there is no way for npcclient to know what it might hit along this path. Every 500msec this operation wakes up and checks its latest movement for collisions, generating a perception called “collision” for the behavior script to react to. Also at each 500msec checkpoint, it checks the owner NPC’s region setting (such as “sunny meadow” in the example above), and if there is a region specifed, the operation checks its current position to make sure the NPC is still “in bounds”. If the NPC has made it outside the region in the last half second, it fires a perception called “out of bounds”. It will not fire another “out of bounds” perception until an “in bounds” perception has been detected.

MovePath Operation

(Net load: 2, CPU Load: 3)

Parameter	Type	Default	Description
path	string	Mandatory	The name of the path to use for the movement.
anim	string		The name of the animation to use for this movement
direction	FORWARD,REVERSE	FORWARD	The direction to move along the path

This operation tell the NPC to move in a predefined path. The path is a named entity in the path network. From a start waypoint to and end waypoint with any number of path points in between. The path will either be followed in the forward or reverse direction. Upon start of this the npc will be forced to the start position of the path. The following example will move the NPC the reverse path to the clock tower.

 Ex: <movepath path="Clock Tower" direction="REVERSE" />

 Ex: <behavior "Ring the Clock">
       <movepath path="Clock Tower" />
       <wait anim="Ring the Clock" />
       <movepath path="Clock Tower" direction="REVERSE" />
     </behavior>

Current implementation will extrapolate on the server and send updates to the client.

The following old description isn't quite in line with current implementation. Sure it should be possible to send the path to the client and do the math there. Suggest to include that as a option to the current implementation. With today implementation the movement could be interrupted and it will stop when finished with the path. To get the looping behavior either the behavior should be set to looping or a loop should be created.

--Start old description:

This operation is another very easy one: <movepath>. It tells the npc to set its preset path to a 3d spline specified in another file by name. Each client will take care of playing the right animations along the spline as the npc progresses. The intent of this operation was really simply for birds to be able to fly through the air as decoration rather than any gameplay reason. Aside from birds, most creatures do not follow 3d spline paths in their normal behaviors.

 Ex: <movepath path="bird1" />

This operation has no present end or duration, and will actually loop if not stopped by another behavior.

This operation has almost no network overhead, as the packed bytes of the spline are sent 1 time across the network to anyone needing to see this npc, and no other network activity happens until the <movepath> operation is interrupted.

This operation also has almost zero CPU overhead, because there is no collision detection and no bounds checking on this type of movement. The reasoning is that since predefined paths are being followed, it is up to the designer/scripter to ensure that the path goes where they want it to and does not hit anything along the way.

--End old description

MoveTo Operation

(Net load: 0, CPU Load: 3)

Parameter	Type	Default	Description
x	float	0.0	X-coordinate to move to
y	float	0.0	Y-coordinate to move to
z	float	0.0	Z-coordinate to move to
vel	float,$WALK,$RUN	Default is to use the velocity from the behavior.	The velocity to use when moving.
anim	string		The name of the animation to use

This operation tells the npc to turn and face a certain point in 3d space, then move in a straight line to that location at a certain speed. The turn is not animated, so if you want an animated turn, you need a <rotate> op in front of this (see below). <moveto> also specifies an animation name to play while performing this move.

 Ex: <moveto x="-38" y="0" z="-169" anim="walk" />

When this operation is executed, the angle necessary to point in the right direction towards this 3d coordinate is calculated and the DR message to start the anim, start the movement and set the rotation angle so it will look correct is sent. Then the operation calculates the time it will take to traverse the distance at the specified speed and suspends itself for that length of time before waking up and completing. Thus, this operation has zero processing during these ½ second update opportunities. No CD checking is done and no bounds checking is done.

When the operation wakes up a few seconds later, the <moveto> is considered complete, and npcclient sends another DR message to stop the movement.

While this operation is very cheap, it is also not very flexible because the coordinates are in the NPCType and not in the NPC. Thus any NPC using this NPC Type with this command in it is going to have to be willing to move to this exact 3d coordinate.

Navigate Operation

(Net load: 1, CPU Load 1)

Parameter	Type	Default	Description
anim	string		The animation to use in the navigation.

The <navigate> operation is a placeholder right now and is simpler than it will be in the future. It is designed to work with <locate> and it moves the NPC in a straight line to the target location found by the <locate> operation.

 Ex: <navigate anim="walk" />

The only thing the operation specifies is the animation to play while moving. It works much like <moveto> but uses the locate target destination instead of a single fixed location. The only network overhead are the Start and Stop DR messages, and the only CPU overhead is calculating how long to sleep between starting and stopping.

For more complex movement the Wander Operation should be used that will use the path network to navigate. Though if there are no path directly to the location to where the NPC should go a combination of Wander and Navigate could be used. Like this example where wander is used to navigate using waypoints and navigate is used navigate into the exact position of the tavern.

 Ex <locate obj="tavern" static="yes" random="yes" range="800" > 
    <wander /> 
    <navigate />

Percept Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
event	string		The name of the perception event to fire. NPC Variables will be replaced.
target	self,tribe,all,target	self	The recipient of this perception
range	float	0.0	If set to something greater than 0.0 this perception will only be deviled if within that range.

This operation allows an NPC to fire a custom perception to himself.

 Ex: <percept event="done wandering" />
     <percept event="need help" target="tribe" range="50" />

Pickup Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
obj	string,perception	perception	The object to pick up. (Only perception implemented)
count	int	1	Number of objects to pick up
equip	slot		name of slot to equip the item in (Not implemented)

This operation allows an NPC to pickup an item he finds on the ground, and optionally equip(Not implemented) it if he can use it. Only objects that are packable will be picked up.

 Ex: <pickup obj="perception" cout="2" />
     <pickup obj="perception" equip="righthand" /> (Not Implemented)

Reproduce Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
type	string		The tribe member type for this.

No Parameters.

The reproduce operation will spawn the target.

 Ex: <reproduce type="Warrior" />

To make make a copy of your self

 Ex: <locate obj="self" />
     <reproduce />

Resurrect Operation

(Net load: 0, CPU Load: 0)

Tribe operation.

Parameter	Type	Default	Description

No Parameters.

This operation will resurrect a tribe member within the radius of tribe home.

 Ex: <resurrect />

This operation should be placed in an behavior that will be executed for dead NPCs. The reaction should as well have the when_dead flag set.

 Ex: <behavior name="Resurrect" completion_decay="200" growth="0" initial="0" when_dead="yes">
        <resurrect/>
     </behavior>
     <react event="tribe:resurrect"    behavior="Resurrect"     inactive_only="yes" when_dead="yes" />

Reward Operation

(Net load: 0, CPU Load: 0)

Tribe operation.

Parameter	Type	Default	Description
resource	string,tribe:wealth	Mandatory	The resource to reward to the tribe.
count	int	1	The number of resource to reward.

Will reward a tribe with a resource. Using the special tribe:wealth keyword will result in a lockup in the tribe for whats the wealth resource.

 Ex: <reward resource="Gold Ore" count="2" />
     <reward resource="tribe:wealth" />

Rotate Operation

(Net load: 1, CPU Load: 0)

Parameter	Type	Default	Description
type	inregion, random, absolute, relative, locatedest, target	Mandatory	The type of rotation operation to perform.
ang_vel	float	0.0	Angular velocity in degree. If 0 the NPC default angular velocity will be used.
anim	string		The animation to use for the rotation operation
max	float	0.0	For inregion and random a range can be defined.
min	float	0.0	For inregion and radom a range can be defined.
value	float	0.0	For absolute and relative a value to add in degrees should be given.

This operation <rotate> can be used to turn to a certain angle, to turn a relative amount, to turn a random amount or to turn to face a previously located object. This turn is animated, to give a more realistic look.

 Ex: <rotate type="random" min="90" max="270" anim="walk" vel="30" />
     <rotate type="locatedest" anim="walk" vel="90" />

The first example here is a random turn of between 90 and 270 degrees from the current heading, with an angular velocity of 30 degrees per second, while playing the “walk” animation. 30 degrees per second means that the maximum turn of 270 degrees will take the npc 9 seconds.

In the second example, we have already used our <locate> operation to find a point of interest near us, and we want to turn to point directly at it. Here a different (faster) angular velocity is specified but other angles aren’t necessary because they are implied by the current position of the NPC and the located special destination.

This operation requires a DR update to start and stop the rotation, as the only networking overhead. CPU overhead is also minimal since npcclient calculates the time required to turn the full amount and puts this script to sleep for that many msec until the turn is done, then stops it.

Sequence Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
name	string	Mandatory	The name of the sequence to control
cmd	start,stop,loop	Mandatory	The control of the sequence to issue.
count	int	1	The number of times to loop the sequence.

Sequences are defined in the map file. They can be started, stopped, or played a number of time with the loop command. This allow the NPC to interact with large animation of world objects. This could be a winch that should run only when manned, a folding bridge or door that open and close etc.

 Ex: <sequence name="winch_up" cmd="start" />

ShareMemories Operation

(Net load: 0, CPU Load: 0)

Tribe operation.

Parameter	Type	Default	Description

No parameters

This operation will share all private memories of the NPC with the tribe. Private memories is created with the Memorize Operation. They can be retrived by the Locate Operation using tribe:memory:"memory name".

 Ex: <share_memories />

Sit Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description

No parameters.

Sit tells the npc to sit down. Use standup operation to stand up again.

 Ex: <sit />

Standup Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description

No parameters.

Standup tells the npc to stand up. Use sit operation to sit down again.

 Ex: <standup />

Talk Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
target	boolean	true	Talk to current target
text	string		The string to send
public	boolean	true	Should this talk go to everyone in range, or only the target if public=false.
type	say,me,my,narrate	say	The type of talk.
command	string		A perception to send to target if it is a NPC. NPC Variables will be replaced.

If target is false, this will queue a talk command to the server from the NPC. If target is true and a target exists the same talk command will be sent to the server but a "command" perception will be sent to the target as well. The target will than be able to react to this perception.

 Ex: <talk target="true" text="Kneel in front of me." command="kneel" />
     <talk type="me" text="is angry" />
     <talk target="true" text="This message is only for you" public="false" />

Teleport Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description

Teleport the NPC to the current active location.

 Ex: <teleport />

Transfer Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
item	string,tribe:wealth	Mandatory	The name of the item to transfer
target	tribe	Mandatory	The target for this transfer.
count	int
Number of items to transfer. -1 is all items.

Transfere a number of item from one NPC to the target.

 Ex: <transfer item="tribe:wealth" target="tribe" />

This example will transfer all of the tribe wealth from the NPC to the tribe.

TribeHome Operation

(Net load: 0, CPU Load: 0)

Tribe operation.

Parameter	Type	Default	Description

No Parameters.

Move the tribe home to the last active position of the NPC. This operation will issue a "tribe:home moved" perception to all members of the tribe.

 Ex: <tribe_home />

TribeType Operation

(Net load: 0, CPU Load: 0)

Tribe operation.

Parameter	Type	Default	Description
type	int	0	Change tribe member type. (Tribe Need Set)

No Parameters.

Move the tribe home to the last active position of the NPC. This operation will issue a "tribe:home moved" perception to all members of the tribe.

 Ex: <tribe_type type="1" />

Visible Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description

No Parameters.

This operation makes the NPC visible if it where invisible. See Invisible Operation.

 Ex: <visible />

Wait Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
duration	float	0.0	The duration to wait
anim	string		The animation to play while waiting.

This operation makes the NPC wait a specified length of time before progressing to the next operation. It will loop an animation during this time also for you, so you can use it for crafting actions, guard monitoring, or whatever you need that is a timed animated activity.

 Ex: <wait anim="stand" duration="30" />

This example tells the NPC to play the “stand” animation and do nothing for 30 seconds. This requires a network DR message with the specified animation, and another to stop the animation when the duration is over. There is almost no CPU required because the script goes to sleep for the duration and is woken up automatically at the end.

As with any other scripted operation, this operation can be interrupted if another behavior preempts this one from completing. So if an npc is playing the above operation, and just standing there for 30 seconds, and is attacked by someone, presumably an attack behavior would become top priority and the npc would stop waiting and attack back.

This concludes the section on the detailed operations possible with npc scripting today. Now we will discuss how these operations work together to define behaviors and how behaviors interact with each other.

Wander Operation

(Net load: 2, CPU Load 1)

Parameter	Type	Default	Description
anim	string		The animation to play while wandering.
vel	float
random	boolean	false	Turn on never ending random wandering.
underground	boolean	invalid	If not set ignore underground, set true only wander underground, if set false never wander underground waypoints
underwater	boolean	invalid	If not set ignore underwater, set true only wander underwater, if set false never wander underwater waypoints
private	boolean	invalid	If not set ignore private, set true only wander private, if set false never wander private waypoints
public	boolean	invalid	If not set ignore public, set true only wander public, if set false never wander public waypoints.
city	boolean	invalid	If not set ignore city, set true only wander city, if set false never wander city waypoints.
indoor	boolean	invalid	If not set ignore indoor, set true only wander indoor, set false never wander indoor waypoints.

Using random <move> and <rotate> operations works well for creating randomized wandering behaviors in open, outdoor spaces and scripters should be using that approach there. However, in tighter, indoor areas like the hydlaa sewers or the dungeon, a more specific type of randomness is required.

The <wander> operation makes the npc in question walk between an independently defined set of “waypoints”. Each waypoint is a 3d coordinate and a tolerance radius. The radius adds a ‘fuzzy’ factor so that multiple npcs sharing the same set of waypoints will not all walk to the exact same centimeter location. Even in tight locations, a tolerance radius of .5-1m will be a lot better than 0m. Waypoints will be created with the path system available as GM commands.

 Ex: <wander anim="walk" />

As you see, the only thing specified by the wander operation is the animation to play while wandering. The NPC starts by walking to the nearest waypoint to its current location, then follows the waypoint choices to decide where to go next. This operation will take the NPC to the current active waypoint as selected by the last Locate Operation.

Each waypoint have a set off properties. It can be marked as indoor,underground,underwater,private,public, or city. If the wander operations in specified with the indoor flag set to true only waypoints with the indoor attribute set to true will be used when wandering. Changing waypoint attributes can be done by the GM command /path (TBD, Not impemented yet, has to be done in DB for now).'

Each waypoint is connected with a path. The path has a set of properites like TELEPORT, NO_WANDER, ONEWAY.

This operation is very light on the network because it is all straight-line navigation between known, preset points. There is 1 DR update per point hit by the npc. It is also quite light on CPU power requirements because the points are known, which means no collision detection has to be done.

One tricky thing about this is that normally non-horizontal walking is accomplished on the client with collision detection with the ground/stairs. In order to get the most accurate-looking result on the client, the client DOES do collision detection on these npcs. However, npcclient does simple linear interpolation between the starting and ending y-coordinates of the 2 waypoints as an approximation. Thus the server and client will not have the identical y-coordinate in all cases. This should almost never be noticeable, though.

Watch Operation

(Net load: 0, CPU Load: 0)

Parameter	Type	Default	Description
type	nearest_actor,nearest_npc,nearest_player,owner,target	Mandatory	The type of watch to do.
range	float	0.0	The watch range. A perception will be generated when watched entity move out of range.
invisible	boolean	false	Set to true to watch invisible entities.
invincible	boolean	false	Set to true to watch invincible entities.
search_range	float	2.0	When watching nearest, this range set the limit for how fare that entity can be.

Watch over nearby entities. The "nearest out of range","owner out of range", or "target out of range" perception will be generated when the watched entity move out of range.

 Ex: <behavior name="Watch">
       <watch type="owner" range="3.0" />
     </behavior>
     <react event="owner out of range"   behavior="follow_chase"  />

In this example the NPC will watch the owner. If the owner move out of the watch range 3.0 the "owner out of range" perception will be fired and the new follow_chase behavior will start.