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[edit] Sensors

Sensors are the causes of logic to do anything. This can be a trigger event such as a nearby object, a key pressed on the keyboard, timed events, etc. When a sensor is triggered, a positive pulse is sent to all linked controllers. The frame after a negative pulse is sent.

[edit] Sensor viewing options

Above the list of sensors there are four buttons and a menu. These are for showing/hiding sensors. They are very useful so unneeded sensors can be hidden and the necessary ones visible and easier to reach. Sensors are sorted per object, every selected object appear in a list and under each object are its sensor.

The menu is labeled Sensors, it looks like a label but is a menu. It has four options:

• Show Objects expands all objects.
• Hide Objects collapses all objects to just a bar with their name.
• Show Sensors expands all sensors.
• Hide Sensors collapses all sensors to bars with their names.

Both these can be controlled individually on the sensor or object.

It is also possible to filter which sensors are viewed:

• Sel shows all selected objects sensors.
• Act shows only active objects sensors.
• Link shows sensors which have a link to a controller.
• State: only sensors connected to a controller of the current state are shown.

[edit] General object options

All objects have two buttons, one which is labeled with their name, and the other labeled Add. The Add button adds a new sensor to the object, the button with the object’s name is for collapsing the object list and hiding its sensors. An object without a sensors is automatically collapsed. Adding a sensor will automatically show the object.

[edit] General sensor options

All sensors have a set of buttons and fields and menu in common. Organized in two rows, these are on the first row, the sensor header:

• X, which deletes the sensor.
• Sensor type menu, see sensor types below.
• Sensor name, this is the name of the sensor. Used to access sensors with python. Needs to be unique among the selected objects.
• Next to it is a “triangle” button for collapsing the sensor.

The top row of buttons on each sensor is also the same for every types, these are:

• True level pulsing, makes the sensor send positive pulses as long as it is activated.
• False level pulsing, makes the sensor send negative pulses as long as it is deactivated.
• Delay field (f), specifies how long time (in logic ticks) between each pulse. This is good for saving performance by not doing things more often than necessary.
• Level, makes the sensor working over state changes. See this page for the state system.
• Tap, sends a positive pulse only once even if the sensor remains true. Only one of Tap or Level can be activated at the same time.
• Inv, inverts the output, sends negative pulses instead of positive and vice versa.

• See Sensor pulses for a more detailed explanation how sensors reacted on the sensor settings.

GameLogic python API.

[edit] Sensor types

[edit] Always sensor

The Always sensor is used for things that need to be done every logic tick, or at every x logic tick (with non-null f), or at start-up (with Tap).

This sensor doesn’t have any options apart from the general sensor ones.

GameLogic python API.

[edit] Delay sensor

The Delay sensor is designed for delaying reactions a number of logic ticks. This is useful if an other action has to be done first or to time events.

The Delay sensor has three options:

• Delay is the number of logic ticks the sensor waits before sending a positive pulse.
• Duration is the time the sensor waits before sending the negative pulse.
• Repeats makes the sensor restart after the delay and duration time is up.

GameLogic python API.

[edit] Keyboard sensor

The Keyboard sensor is for detecting keyboard input, it can also save keyboard input to a String property.

The first row of buttons (Key one) is for single key presses. Press the button with no label and a key to assign that key to the sensor. This is the active key, which will trigger the positive pulse. Click the button and then click outside of the button to deassign the key. The All keys button will hide all other button and send positive pulses on all key presses. This is useful for custom key maps with a Python controller.

The Hold buttons work the same way as the key button but won’t set off a positive pulse unless hold down while the key button is pressed. You can have up to two of hold buttons. If a key is assigned here, a positive pulse won’t be send unless both/all keys are pressed. This is useful if you wish to have for example CtrlR or ⇧ ShiftAltEsc to do a specific action.

LogToggle field assigns a Bool property which determines if the keystroke will be logged in the String property (true) or not (false). This needs to be here if you wish to log your keystrokes.

Target is the String property to which the keystrokes are saved. Together with a Property sensor this can be used for example to enter passwords.

GameLogic python API.

[edit] Mouse sensor

The Mouse sensor is for detecting mouse input. The controller consist only of a list of types of mouse events. These are:

• Left button.
• Middle button.
• Right button
• Wheel Up, the scroll wheel of the mouse.
• Wheel Down, the scroll wheel of the mouse.
• Movement, any movement with the mouse.
• Mouse over, detects if the mouse is over the object.
• Mouse over any, detects if the mouse is over any object.

There is no logic brick for specific mouse movement and reactions (such as first person camera), these has to be coded in python.

GameLogic python API.

[edit] Touch sensor

The Touch sensor sends a positive pulse when the object is in contact with another object. The MA field is for filtering materials. Only contact with the material in this field will generate a positive pulse. Leave blank for touch with any object. The positive pulse is sent on collision and the negative pulse is sent once the objects are no longer in contact. For a continuous pulse while they are in contact use “True Pulse triggering”.

GameLogic python API.

[edit] Collision sensor

A Collision sensor works like a Touch sensor but can also filter by property. Only objects with the property with that name will generate a positive pulse upon collision. Leave blank for collision with any object.

The Pulse button makes it sensible to other collisions even if it is still in touch with the object that triggered the last positive pulse.

The M/P button toggles between material and property filtering.

[edit] Near sensor

A Near sensor detects objects that are within a specific distance of themselves. It can filter objects with properties, like the Collision sensor.

Distance is the number of blender units it will detect objects within. Reset is the distance the object needs to be to reset the sensor (send a negative pulse).

GameLogic python API.

[edit] Radar sensor

A Radar sensor works much like a Near sensor, but only within an angle from an axis, forming an invisible cone with the top in the objects’ centre and base at a distance on an axis. It has a property filter field (Prop). Next to it is the axis menu, which determines the direction of the radar cone. The ± signs is whether it is on the axis direction (+), or the opposite (-).

Angle determines the width of the cone, and Distance its length.

This sensor is useful for giving bots sight only in front of them, for example. Note that it does see through other objects.

GameLogic python API.

[edit] Property sensor

The Property sensor detect changes in the objects properties. This sensor has four modes:

• Equal triggers a positive pulse when the property value matches the value in the sensor. The Prop field is for the name of the property, and Value is for the value it has to match to send a positive pulse.
• Not Equal triggers a positive pulse when the property value differs from the value in the sensor. The same fields as Equal, but Value represents the value the property has to differ from in order to set off a pulse.
• Interval triggers a positive pulse when the value of the property is between the Min and Max values of the sensor. For “more than”, enter the property name in the Max field and the lowest number for triggering in the Min field. For “less than”, enter the property name in the Min field and the maximum value in the Max field. Names of other properties can also be entered to compare properties.
• Changed sends a positive pulse as soon as the property value changes.

GameLogic python API.

[edit] Random sensor

The Random sensor generates random pulses. It has a Seed field to enter the initial seed. 0 is not random, for testing and debugging purposes.

GameLogic python API.

[edit] Ray sensor

The Ray sensor shoots a ray in the direction of an axis and sends a positive pulse once it hits something. It can be filtered to only detect objects with a given material or property.

It shares a lot of buttons and fields with Radar sensor. The X button make it x-ray, it sees through objects that doesn’t have the property or material specified in the filter field.

GameLogic python API.

[edit] Message sensor

Messages can be used to send either text or property values. The Message sensor sends a positive pulse once a message is sent anywhere in the engine. It can filter to only send a pulse upon a message with a specific subject.

GameLogic python API.

[edit] Joystick sensor

The Joystick sensor detect joystick events.

GameLogic python API.

[edit] Actuator sensor

The Actuator sensor is set off when an actuator with the name specified in the Act field is activated.

GameLogic python API.