Actuators are the executing LogicBricks. They can be compared with muscles or glands in a life form.
Action play modes
Plays the Action from "Sta" to "End" at every positive pulse the Actuator gets. Other pulses while playing are discarded.
Plays the Action from "Sta" to "End" on activation. When the activation ends it plays backwards from the current position. When a new activation reaches the Actuator the Action will be played from the current position onwards.
Plays the Action in a loop as long as the pulse is positive. It stops at the current position when the pulse turns negative.
This plays the Action repeatedly as long as there is a positive pulse. When the pulse stops it continues to play the Action to the end and then stops.
Plays the Action for exactly the frame indicated in the property entered in the field "Prop:".
The Motion Actuator is maybe the most important Actuator. It moves, rotates or applies a velocity to objects.
The simplest case of using a Motion Actuator is to move the object. This is done with the "dLoc" values in the third row. Every time the actuator is triggered by an impulse it moves the object by the amount given in the "dLoc" row. The three values here stand for X-, Y- and Z-axis. So when you enter a 1.0 in the first field the object is moved one unit per time unit of the game (the clock in the game engine ticks in frames, roughly 1/25 of a second, for exact timings use the Timer Property).
The buttons labeled "L" behind each row in the motion actuator, determine if the motion applied should be treated as global or local. If the button is pushed (dark green) the motion is applied based on the local axis of the object. If the button is not pressed the motion is applied based on the global (world) axis.
Values in this row act as forces that apply to the object. This only works for dynamic objects.
Values in this row act as rotational forces (Torque) that apply to the object. This works only for dynamic objects. Positive values rotate counter-clock-wise.
Offset the object as indicated in the value fields
Rotate the object for the given angle (36 is a full rotation). Positive values rotate clock-wise.
Sets (overrides current velocity) the velocity of the object to the given values. When "add" is activated the velocity is added to the current velocity.
Sets the angular velocity to the given values. Positive values rotate counter-clock-wise.
The Motion Actuator starts to move objects on a pulse (TRUE) and stops on a FALSE pulse. To get a movement over a certain distance, you need to send a FALSE pulse to the motion actuator after each positive pulse.
With the Constraint Actuator you can limit an object's freedom to a certain degree.
With the MenuButton you specify which channel's freedom should be constrained. With the NumberButtons "Min" and "Max" you define the minimum and maximum values for the constraint selected. To constrain an object to more than one channel simply use more than one Constraint actuator.
The Ipo Actuator can play the Ipo-curves for the object that owns the Actuator. If the object has a child with an Ipo (in a parenting chain) and you activate "Child" in the Actuator, the Ipo for the child is also played.
The "Force" Button will convert the "Loc" Ipo curves into forces for dynamic objects. When pressed, the "L" Button appears which cares for applying the forces locally to the objects coordinate system.
Ipo play modes
Plays the Ipo from "Sta" to "End" at every positive pulse the Actuator gets. Other pulses received while playing are discarded.
Plays the Ipo from "Sta" to "End" on the first positive pulse, then backwards from "End" to "Sta" when the second positive pulse is received.
Plays the Ipo for as long as the pulse is positive. When the pulse changes to negative the Ipo is played from the current frame to "Sta".
Plays the Ipo in a loop for as long as the pulse is positive. It stops at the current position when the pulse turns negative.
This plays the Ipo repeatedly for as long as there is a positive pulse. When the pulse stops it continiues to play the Ipo to the end and then stops.
Plays the Ipo for exactly the frame indicated by the property named in the field "Prop:".
Currently the following Ipos are supported by the game engine:
Loc, Rot, Size and Col
Loc, Rot, RGB, Energy
Loc, Rot, Lens, ClipSta, ClipEnd
The Camera Actuator tries to mimic a real cameraman. It keeps the actor in the field of view and tries to stay at a certain distance from the object. The motion is soft and there is some delay in the reaction on the motion of the object.
Enter the object that should be followed by the camera (you can also use the Camera Actuator for non-camera objects) into the "OB:" field. The field "Height:" determines the height above the object the camera stays at. "Min:" and "Max:" are the bounds of distance from the object to which the camera is allowed to move. The "X" and "Y" buttons specify which axis of the object the camera tries to stay behind.
The Sound Actuator plays a SoundObject loaded using the SoundButtons (see Section 26.10). Use the MenuButton to browse and choose between the SoundObjects in the scene.
Sound play modes (MenuBut)
Plays the sound for as long as there is a positive pulse.
Plays the sound to the end, when a positive pulse is given.
Plays and repeats the sound, when a positive pulse is given.
Plays the sound repeatedly, when a positive pulse is given. When the pulse stops the sound is played to its end.
Checking the "Custom set." button will copy the SoundObject (sharing the sample data) and allows you to quickly change the volume and pitch of the sound with the appearing NumberButtons.
Assigns a value or Expression (given in the "Value" field) to a Property. For example with an Expression like "Proppy + 1" the "Assign" works like an "Add". To assign strings you need to add quotes to the string ("...").
Adds the value or result of an expression to a property. To subtract simply give a negative number in the "Value:" field.
More on using Expressions can be found in Section 26.9.
This actuator performs actions on Objects itself, like adding new objects, deleting objects, etc.
Edit Object Actuator types
Keep the object you'd like to add on a seperate and hidden layer. You will see an error message on the console or debug output when not following this rule.
Enter the name of the Object to add in the "OB:" field. The "Time:" field determines how long (in frames) the object should exist. The value "0" denotes it will exist forever. Be careful not to slow down the game engine by generating too many objects! If the time an object should exist is not predictable, you can also use other events (collisions, properties, etc.) to trigger an "End Object" for the added object using LogicBricks.
With the "linV" buttons it is possible to assign an initial velocity to the added object. This velocity is given in X, Y and Z components. The "L" button stands for local. When it is pressed the velocity is interpreted as local to the added object.
The Scene Actuator is meant for switching Scenes and Cameras in the game engine or adding overlay or background scenes.
Choose the desired action with the MenuButton and enter an existing camera or scene name into the text field. If the name does not exist, the button will be blanked!
Simply restarts and resets the scene. It has the same effect as stopping the game with ESC and restarting with PKEY.
Switch to the scene indicated into the text field. During the switch all properties are reset!
Switch to the Camera indicated in the text field.
Adds an overlay scene which is rendered on top of all other (existing) scenes.
Adds a background scene which will be rendered behind all other scenes.
Removes a scene.
Suspends a scene until "Resume Scene" is called.
Resumes a suspended Scene.
An often-needed function for games is a random value to get more variation in movements or enemy behavior.
The Seed parameter is the value fed into the random generator as a start value for the random number generation. Because computer generated random numbers are only "pseudo" random (they will repeat after a (long) while) you can get the same random numbers again if you choose the same Seed.
Enter the name of the property you want to be filled with the random number into the "Property:" field.
Random Actuators types
This LogicBrick sends a message out, which can be received and processed by the Message Sensor.
The "To:" field indicates that the message should only be sent to objects with the Property indicated by "To:". The subject of the message is indicated in the "Subject:" field. With these two possibilities you can control the messaging very effectively.
The body (content) of the message can either be a text ("Body:") string or the content of a Property when "T/P" is activated ("Propname:"). See Section 27.1.11 on how to get the body of a message.