Table of Contents

Blackboard Nodes

The animation graph provides nodes to read and write values from and to a blackboard. For this, the game object on which the animation controller component is attached, or one of its parent nodes, also needs to hold a blackboard component.

Note:

If no blackboad is available, these nodes will typically silently not do anything. If a blackboard is available, but the desired entry is not (yet) in the blackboard, they may add the entry or log a warning and assume a default value.

Set Number Node / Set Bool Node

When activated, this node writes a given value to the blackboard. If the activation pin is not connected, at all, the node updates the blackboard with the incoming number every update.

Node Properties

  • Blackboard Entry: The name of the blackboard entry (variable) to write to.

  • Number / Bool: The value to write in case the value input pin is connected.

Input Pins

  • Activate: When triggered, the node changes the blackboard value.

  • Number / Bool: The value to write. If not connected, the value configured on the node is used.

Get Number Node / Get Bool Node

Outputs the value of a specific blackboard entry.

Node Properties

  • Blackboard Entry: The name of the blackboard entry (variable) to read.

Output Pins

  • Number / Bool: The value of the entry. If the entry doesn't exist, the pin outputs zero.

Check Number Node

This node monitors a blackboard value and compares it to a reference value. When the result of the comparison changes, the On True or On False output pin gets triggered for one frame.

Node Properties

  • Blackboard Entry: The name of the blackboard entry (variable) to monitor.

  • Reference Value: A reference value for the comparison.

  • Comparison: The way the two values get compared.

Output Pins

  • On True: Gets triggered for one frame when the comparison result changes to true.
  • On False: Gets triggered for one frame when the comparison result changes to false.
  • Is True: Outputs the result of the comparison. This is a data pin that can always be read, contrary to the other two pins that are event pins and only get triggered when something changes.
  • Is False: Outputs the opposite value of Is True.

Check Bool Node

This node monitors a boolean blackboard value and compares it to true. When the result of the comparison changes, the On True or On False output pin gets triggered for one frame.

Node Properties

  • Blackboard Entry: The name of the blackboard entry (variable) to monitor.

Output Pins

  • On True: Gets triggered for one frame when the value changes to true.
  • On False: Gets triggered for one frame when the value changes to false.
  • Bool: Outputs the blackboard value. This is a data pin that can always be read, contrary to the other two pins that are event pins and only get triggered when the value changes.

OnChanged Node

This node monitors a blackboard value and triggers its output event node when the value changes. This should be used when any change to a variable is of interest.

Node Properties

  • Blackboard Entry: The name of the blackboard entry (variable) to monitor.

Output Pins

  • On Value Changed: Gets triggered for one frame when the value changes somehow.

See Also

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