UnrealScript Game Programming Cookbook

AI and Navigation

132

The OffsetX and OffsetY variables tell us how far to the left and right, and then

forward and backward, we want our bot to move each time the function is called.

Our target location is where we want to set the bot. We're simply taking our current

pawn's location, and subtracting it from the offset, that is, where we want the bot to

be going. Each time MoveRandom() is called, it will pick a random integer between

the minimum and maximum values you've set.

At the end of this function we're informing the bot to go to the wander state.

/*=======================================================

* Math for our wandering state

=======================================================*/

function MoveRandom()

{

local int OffsetX;

local int OffsetY;

// set a random number for our X value

OffsetX = Rand(1300)-Rand(700);

// set a random number for our Y value

OffsetY = Rand(1100)-Rand(1100);

// distance left or right of the pawn

TargetLocation.X = Pawn.Location.X + OffsetX;

// distance in front of or behind the pawn

TargetLocation.Y = Pawn.Location.Y + OffsetY;

/** prevents the pawn from quickly aiming up and down

the Z axis while moving */

TargetLocation.Z = Pawn.Location.Z;

// move to the random location

GoToState('Wander');

}

5. The wander state only has one function, and that is MoveTo(TargetLocation).
   The math for the target location (a vector) was previously done in our MoveRandom()
   function.
   /*=====================================================
   
   
   • Tells the pawn to start wandering
     =======================================================*/
     state Wander
     {
     Begin:
   
   
   
   

// move to a location (vector)

MoveTo(TargetLocation);

}