Graphics Reference
In-Depth Information
Now a ray is cast on the other side of the bot:
if(Physics.Raycast( myTransform.position,myTransform.forward +
( myTransform.right * -0.5f ), out hit, wallAvoidDistance ))
{
When the ray is cast here, the code checks obstacleHitType to see whether it has been
set by the previous raycast. If it has not yet been set, its value will be at 0; this tells us that
this ray is the first one to get a hit and that the function has only found an obstacle on this
side—obstacleHitType gets set to 2:
// obstacle
if( obstacleHitType==0 )
{
// if we haven't hit anything yet, this is a
// type 2
obstacleHitType=2;
} else {
If we have found something on this side via the raycast and obstacleHitType is not
at 0, we know that both raycasts have found obstacles (since the first raycast set obstacle-
HitType to 1 if it found something earlier). To represent obstacles found on both sides,
obstacleHitType gets set to 3:
// if we have hits on both left and right
// raycasts, it's a type 3
obstacleHitType=3;
}
}
The return result of this function is the value of obstacleHitType. Earlier in this chap-
ter, the main UpdateAI() function used this return result to decide which way to turn or
whether to go into reverse mode.
return obstacleHitType;
}
The next part of BaseAIController.cs is TurnTowardTarget(). This function does
exactly what it seems—it will turn the bot (more specifically, the transform set in the vari-
able rotateTransform) toward the transform passed to it as a parameter:
public void TurnTowardTarget( Transform aTarget )
{
if(aTarget==null)
return;
Earlier in this chapter, in the UpdateAI() function, we looked at how AIState.translate_
along_waypoint calculated the relative position of its target—it's the same here, with the
relative position of the target calculated with Unity's Transform.InverseTransformPoint()
function:
relativeTarget = rotateTransform.InverseTransformPoint
( aTarget.position ); // note we use rotateTransform as a rotation
// object rather than myTransform!
