The first toddler steps of AI

Entry posted by Chris Paulson · December 2, 2009

1,931 views

Youtube video of my AI.

Red line is path found by recast.

White text is current behaviours running in behaviour tree.

Here's what the BT looks like (yes it is C++)

alive::Node* moveToEnemy(std::string type = "walk")
{
   return alive::TreeBuilder()
		.execute<ActionMoveToEnemy>()
			.type(type)
		.end();
}

alive::Node* resetToStart()
{
   return alive::TreeBuilder()
	.composite<alive::SequenceNode>()
		.execute<ActionCurrentMode>()
			.mode("resetToStart")
		.end()
		.execute<ActionAnimate>()
			.Speed(1)
			.Name("rifle_idle")
			.AnimType(PLAY_REPEAT)
		.end() 
		.composite<alive::ParallelNode>()
			.execute<LookForward>()
				.Parallel(true)
			.end()
			.execute<ActionStopMove>()
			.end()
		.end()
	.end();
}

alive::Node* gunAttack()
{
   return alive::TreeBuilder()
	.composite<alive::SequenceNode>()
		.execute<ActionCurrentMode>()
			.mode("gunAttack")
		.end()
		.execute<hasGun>()
			.Equals(true)
		.end()
		.execute<CanSeeEnemy>()
			.Equals(true)
			.Parallel(false)
		.end()
		.execute<ActionStopMove>()
		.end()
		.execute<ActionAnimate>()
			.Speed(1)
			.TranTime(1)
			.Name("rifle_idle")
			.AnimType(PLAY_REPEAT)
		.end() 
		.composite<alive::ParallelNode>()
			.execute<CanSeeEnemy>()
				.Equals(true)
			.end()
			.execute<WithinFiringRange>()
				.Equals(true)
			.end()
			.execute<AimAtEnemy>()
			.end()
			.composite<alive::SequenceNode>()
				.decorator<alive::RepeatNode>()
					.composite<alive::SelectorNode>()
						.execute<NeedToAim>()
							.Equals(true)
						.end()
						.execute<FireAtEnemy>()
						.end()
						.execute<ActionTimer>()
							.time(0.01)
						.end()
					.end()
				.end()
			.end()
		.end()
	.end();
}


alive::Node* moveToAttackPosition()
{
   return alive::TreeBuilder()
	.composite<alive::SequenceNode>()
		.execute<ActionCurrentMode>()
			.mode("moveToAttackPosition")
		.end()
		.execute<hasGun>()
			.Equals(true)
		.end()
		.add(resetToStart()).end()
		.composite<alive::ParallelNode>()
			.execute<IsSeenIdle>()
				.Equals(false)
			.end()
			.execute<WithinFiringRange>()
				.Equals(true)
			.end()
			.execute<hasGoodAimAtEnemy>()
				.Equals(false)
			.end()
			.add(moveToEnemy()).end()
		.end()
	.end();
}

alive::Node* moveToWithinRifleRange()
{
   return alive::TreeBuilder()
	.composite<alive::SequenceNode>()
		.execute<ActionCurrentMode>()
			.mode("moveToWithinRifleRange")
		.end()
		.execute<hasGun>()
			.Equals(true)
		.end()
		.composite<alive::ParallelNode>()
			.execute<LookForward>()
				.Parallel(true)
			.end()
			.execute<IsSeenIdle>()
				.Equals(false)
			.end()
			.execute<WithinFiringRange>()
				.Equals(false)
			.end()
			.add(moveToEnemy()).end()
		.end()
	.end();
}
alive::Node* hunt()
{
   return alive::TreeBuilder()
	.composite<alive::SequenceNode>()
		.execute<ActionCurrentMode>()
			.mode("hunt")
		.end()
		.composite<alive::ParallelNode>()
			.execute<LookForward>()
				.Parallel(true)
			.end()
			.execute<IsSeenIdle>()
				.Equals(false)
			.end()
			.execute<CanSeeEnemy>()
				.Equals(false)
			.end()
			.add(moveToEnemy()).end()
		.end()
	.end();
}

void Crawler::init(Pedestrian* pPedestrian, Vision *pvision, ActorGun *pRifle)
{
//			.decorator<alive::RepeatNode>()
//	.decorator<alive::ErrorHandlerNode>()
   alive::Node* behave = alive::TreeBuilder()
.decorator<alive::RepeatNode>()
	.add(resetToStart()).end()
	.composite<alive::SelectorNode>()
		// Reset to default
		// Attack with gun
		.add(gunAttack()).end()

		// Move to a aim position
		.add(moveToAttackPosition()).end()

		// Move to attack (to melle or to get in firing range)
		.add(moveToWithinRifleRange()).end()

		// Hunt
		.add(hunt()).end()

		// Move to waypoint
		.composite<alive::ParallelNode>()
			.execute<CanSeeEnemy>()
				.Equals(false)
			.end()
			.composite<alive::SequenceNode>()
				.add(resetToStart()).end()
				.execute< CrawlerCompare<bool> >()
					.Variable(&Crawler::hasWaypoint)
					.Reference(true)
				.end()
				.execute<ActionMoveToWaypoint>()
				.end()
			.end()
		.end()
		// Idle
		.composite<alive::SequenceNode>()
			.execute<ActionCurrentMode>()
				.mode("idle")
			.end()
			.composite<alive::ParallelNode>()
				.execute<CanSeeEnemy>()
					.Equals(false)
				.end()
				.composite<alive::SequenceNode>()
					.add(resetToStart()).end()
					.execute<ActionAnimate>()
						.Speed(1)
						.Name("rifle_idle")
						.AnimType(PLAY_ONCE)
					.end()
				.end()
			.end()
		.end()
	.end()
.end();

rifle = pRifle;
pedestrian = pPedestrian;
vision = pvision;

//	alive::InitializeWithBlackboard<Crawler> initialize(*this);
alive::InitializeWithBlackboard<Crawler> *initialize = new alive::InitializeWithBlackboard<Crawler>(*this);
m_Brain.registry.setAddObserver(*initialize);
   m_Brain.registry.setAddObserver(*new InitializeAction(*this));

   //m_Brain.registry.setAddObserver(*new InitializeAction(*this));
   m_Brain.add(*behave);
}

void Crawler::Update( float gameLoopTime )
{
pedestrian->currentAction = pedestrian->currentMode + ",";
m_Brain.tick();
pedestrian->Update( gameLoopTime );
}

void Crawler::Render( float gameLoopTime)
{
pedestrian->Render( gameLoopTime );
vision->Render( pedestrian->scene->cam );
}