Scripting: Communication with Actions

Actions add a lot of performance friendly game mechanic functionality and are at the core of constructing cool game objects from entities. Actions themselves have their own Lua library “action.command()“ for getting and setting property values and specific actions have direct lua Event calls such as the “function doDamage(..)“

getActionID() - How to find the Action ID

The simplest way to control an action is to use the action.setActionParam(..) and action.getActionParam(..) but all lua actions require an identifier for locating which action to target, this known as the actionID.

To pass data between Lua and actions you must first know the actions ID. Each action added to the object increments the action ID by +1 starting from 0. To get the ID all you need to know is the name of the action and the object ID.

Params:

entityID : The objID to use to get the action data from.
actionName : The name of the action, this can be found by looking at the actions header in the property panel.

-- Set the action id to default at -1 for catching errors.
actionID = -1;
obj = -1;
 
function onInit(objID)
    obj = objID;
end
 
function postInit()
    actionID = action.getActionID(obj ,"ActionName");
end

You should have noticed that this call was put in the postInit() Event. This is to ensure that all actions on all objects have been created/started before you send any commands.

Action property Setters and Getters

To change an action property dynamically and to examine a current property we use the action library action.setActionParam(..) and action.getActionParam(..). The commands as with all action commands require the action id and object id. This command requires a string argument pass containing the name of the property to be changed.

-- Set the action id to default at -1 for catching errors.
actionID = -1;
obj = -1;
 
function onInit(objID)
	obj = objID;
end
 
-- Use the post init to grab the action id
function postInit()
	 actionID = action.getActionID(obj ,"PhysX RigidBody");
	 setParam();
	 sprint("value: "..getParam());
end
 
function setParam()
	-- Disable Physics on this object.
	value = false;
	action.setActionParam(obj, actionID, "PRB Enabled", tostring(value));
end
 
function getParam()
	value = action.getActionParam(obj, actionID,"PRB Enabled");
	return value;
end