Use view frustum for traffic spawning and cleanup

rwengine/include/ai/TrafficDirector.hpp

@@ -9,6 +9,7 @@
 
 class GameObject;
 class GameWorld;
+class ViewCamera;
 
 class TrafficDirector
 {
@@ -16,17 +17,17 @@ public:
 	
 	TrafficDirector(AIGraph* graph, GameWorld* world);
 	
-	std::vector< AIGraphNode* > findAvailableNodes(AIGraphNode::NodeType type, const glm::vec3& near, float radius);
+	std::vector< AIGraphNode* > findAvailableNodes(AIGraphNode::NodeType type, const ViewCamera& camera, float radius);
 	
 	void setDensity(AIGraphNode::NodeType type, float density);
 
 	/**
 	 * Creates new traffic at available locations.
-	 * @param center The area to spawn around
+	 * @param camera The camera to spawn around
 	 * @param radius the maximum distance to spawn in
 	 * @param max The maximum number of traffic to create.
 	 */
-	std::vector<GameObject*> populateNearby( const glm::vec3& center, float radius, int maxSpawn = -1 );
+	std::vector<GameObject*> populateNearby( const ViewCamera& camera, float radius, int maxSpawn = -1 );
 
 	/**
 	 * Sets the maximum number of pedestrians and cars in the traffic system
@@ -40,4 +41,4 @@ private:
 	float carDensity;
 	int maximumPedestrians;
 	int maximumCars;
-};
+};

rwengine/include/engine/GameWorld.hpp

@@ -21,6 +21,7 @@ class CharacterObject;
 class InstanceObject;
 class VehicleObject;
 
+class ViewCamera;
 #include <render/VisualFX.hpp>
 #include <data/ObjectData.hpp>
 
@@ -76,10 +77,23 @@ public:
 	 * @param name The name of the IPL as it appears in the games' gta.dat
 	 */
 	bool placeItems(const std::string& name);
-	
-	void createTraffic(const glm::vec3& near);
-	void cleanupTraffic(const glm::vec3& focus);
-	
+
+	/**
+	 * @brief createTraffic spawn transitory peds and vehicles
+	 * @param viewCamera The camera to create traffic near
+	 *
+	 * The position and frustum of the passed in camera is used to determine
+	 * the radius where traffic can be spawned, and the frustum is used to avoid
+	 * spawning traffic in view of the player.
+	 */
+	void createTraffic(const ViewCamera& viewCamera);
+
+	/**
+	 * @brief cleanupTraffic Cleans up traffic too far away from the given camera
+	 * @param viewCamera
+	 */
+	void cleanupTraffic(const ViewCamera& viewCamera);
+
 	/**
 	 * Creates an instance
 	 */

rwengine/src/ai/TrafficDirector.cpp

@@ -6,6 +6,7 @@
 #include <objects/GameObject.hpp>
 #include <objects/CharacterObject.hpp>
 #include <objects/VehicleObject.hpp>
+#include <render/ViewCamera.hpp>
 #include <core/Logger.hpp>
 
 #include <glm/gtx/string_cast.hpp>
@@ -18,36 +19,39 @@ maximumPedestrians(20), maximumCars(10)
 
 }
 
-std::vector< AIGraphNode* > TrafficDirector::findAvailableNodes(AIGraphNode::NodeType type, const glm::vec3& near, float radius)
+std::vector< AIGraphNode* > TrafficDirector::findAvailableNodes(AIGraphNode::NodeType type, const ViewCamera& camera, float radius)
 {
 	std::vector<AIGraphNode*> available;
 	available.reserve(20);
 
-	graph->gatherExternalNodesNear(near, radius, available);
+	graph->gatherExternalNodesNear(camera.position, radius, available);
 
 	float density = type == AIGraphNode::Vehicle ? carDensity : pedDensity;
 	float minDist = (10.f / density) * (10.f / density);
+	float halfRadius2 = std::pow(radius / 2.f, 2.f);
 
-	// Determine if anything in the open set is blocked
-	for ( auto it = available.begin(); it != available.end(); )
-	{
+	// Check if any of the nearby nodes are blocked by a pedestrian standing on it
+	// or because it's inside the view frustum
+	for (auto it = available.begin(); it != available.end();) {
 		bool blocked = false;
-		for ( auto obj : world->pedestrianPool.objects )
-		{
-			// Sanity check
-			if ( glm::distance2( (*it)->position, obj.second->getPosition() ) <= minDist )
-			{
+		float dist2 = glm::distance2(camera.position, (*it)->position);
+
+		for (auto& obj : world->pedestrianPool.objects) {
+			if (glm::distance2( (*it)->position, obj.second->getPosition() ) <= minDist) {
 				blocked = true;
 				break;
 			}
 		}
+
+		// Check that we're not going to spawn something right where the player is looking
+		if (dist2 <= halfRadius2 && camera.frustum.intersects((*it)->position, 1.f)) {
+			blocked = true;
+		}
 		
-		if ( blocked )
-		{
+		if (blocked) {
 			it = available.erase( it );
 		}
-		else
-		{
+		else {
 			it++;
 		}
 	}
@@ -68,17 +72,28 @@ void TrafficDirector::setDensity(AIGraphNode::NodeType type, float density)
 	}
 }
 
-std::vector<GameObject*> TrafficDirector::populateNearby(const glm::vec3& center, float radius, int maxSpawn)
+std::vector<GameObject*> TrafficDirector::populateNearby(const ViewCamera& camera, float radius, int maxSpawn)
 {
 	int availablePeds = maximumPedestrians - world->pedestrianPool.objects.size();
 
 	std::vector<GameObject*> created;
 
-	// Spawn vehicles at vehicle generators
-	/// @todo avoid spawning in view frustum unless alwaysSpawn == true
+	/// @todo Check how "in player view" should be determined.
 
+	// Don't check the frustum for things more than 1/2 of the radius away
+	// so that things will spawn as you drive towards them
+	float halfRadius2 = std::pow(radius/ 2.f, 2.f);
+
+	// Spawn vehicles at vehicle generators
 	for (auto& gen : world->state->vehicleGenerators) {
-		if (glm::distance2(center, gen.position) < radius * radius) {
+		float dist2 = glm::distance2(camera.position, gen.position);
+		if (dist2 < radius * radius) {
+			if (dist2 <= halfRadius2 && camera.frustum.intersects(gen.position, 1.f)) {
+				if (! gen.alwaysSpawn) {
+					// Don't spawn in the view frustum unless we're forced to
+					continue;
+				}
+			}
 			auto spawned = world->tryToSpawnVehicle(gen);
 			if (spawned) {
 				created.push_back(spawned);
@@ -87,7 +102,7 @@ std::vector<GameObject*> TrafficDirector::populateNearby(const glm::vec3& center
 	}
 
 	auto type = AIGraphNode::Pedestrian;
-	auto available = findAvailableNodes(type, center, radius);
+	auto available = findAvailableNodes(type, camera, radius);
 	
 	if( availablePeds <= 0 )
 	{

rwengine/src/engine/GameWorld.cpp

@@ -23,6 +23,12 @@
 #include <data/CutsceneData.hpp>
 #include <loaders/LoaderCutsceneDAT.hpp>
 
+#include <render/ViewCamera.hpp>
+
+// Behaviour Tuning
+constexpr float kMaxTrafficSpawnRadius = 100.f;
+constexpr float kMaxTrafficCleanupRadius = kMaxTrafficSpawnRadius * 1.25f;
+
 class WorldCollisionDispatcher : public btCollisionDispatcher
 {
 public:
@@ -218,39 +224,38 @@ InstanceObject *GameWorld::createInstance(const uint16_t id, const glm::vec3& po
 	return nullptr;
 }
 
-void GameWorld::createTraffic(const glm::vec3& near)
+void GameWorld::createTraffic(const ViewCamera& viewCamera)
 {
 	TrafficDirector director(&aigraph, this);
 	
-	director.populateNearby( near, 100, 5 );
+	director.populateNearby( viewCamera, kMaxTrafficSpawnRadius, 5 );
 }
 
-void GameWorld::cleanupTraffic(const glm::vec3& focus)
+void GameWorld::cleanupTraffic(const ViewCamera& focus)
 {
-	for ( auto& p : pedestrianPool.objects )
-	{
-		if ( p.second->getLifetime() != GameObject::TrafficLifetime )
-		{
+	for (auto& p : pedestrianPool.objects) {
+		if (p.second->getLifetime() != GameObject::TrafficLifetime) {
 			continue;
 		}
 		
-		if ( glm::distance( focus, p.second->getPosition() ) >= 100.f )
-		{
-			destroyObjectQueued( p.second );
+		if (glm::distance( focus.position, p.second->getPosition() ) >= kMaxTrafficCleanupRadius) {
+			if (! focus.frustum.intersects(p.second->getPosition(), 1.f)) {
+				destroyObjectQueued( p.second );
+			}
 		}
 	}
-	for ( auto& p : vehiclePool.objects )
-	{
-		if ( p.second->getLifetime() != GameObject::TrafficLifetime )
-		{
+	for ( auto& p : vehiclePool.objects ) {
+		if (p.second->getLifetime() != GameObject::TrafficLifetime) {
 			continue;
 		}
 
-		if ( glm::distance( focus, p.second->getPosition() ) >= 100.f )
-		{
-			destroyObjectQueued( p.second );
+		if (glm::distance( focus.position, p.second->getPosition() ) >= kMaxTrafficCleanupRadius) {
+			if (! focus.frustum.intersects(p.second->getPosition(), 1.f)) {
+				destroyObjectQueued( p.second );
+			}
 		}
 	}
+
 	destroyQueuedObjects();
 }
 

rwgame/RWGame.cpp

@@ -463,13 +463,13 @@ void RWGame::tick(float dt)
 				throw;
 			}
 		}
-		
-		if ( state->playerObject )
-		{
+
+		/// @todo this doesn't make sense as the condition
+		if ( state->playerObject ) {
+			nextCam.frustum.update(nextCam.frustum.projection() * nextCam.getView());
 			// Use the current camera position to spawn pedestrians.
-			auto p = nextCam.position;
-			world->cleanupTraffic(p);
-			world->createTraffic(p);
+			world->cleanupTraffic(nextCam);
+			world->createTraffic(nextCam);
 		}
 	}
 	

tests/test_lifetime.cpp

@@ -1,6 +1,7 @@
 #include <boost/test/unit_test.hpp>
 #include <glm/gtx/string_cast.hpp>
 #include <objects/InstanceObject.hpp>
+#include <render/ViewCamera.hpp>
 #include "test_globals.hpp"
 
 BOOST_AUTO_TEST_SUITE(LifetimeTests)
@@ -19,7 +20,9 @@ BOOST_AUTO_TEST_CASE(test_cleanup)
 		BOOST_CHECK( search != objects.end() );
 	}
 	
-	Global::get().e->cleanupTraffic(glm::vec3(0.f, 0.f, 0.f));
+	ViewCamera testCamera;
+	testCamera.position = glm::vec3(0.f, 0.f, 0.f);
+	Global::get().e->cleanupTraffic(testCamera);
 	
 	{
 		auto search = objects.find(id);

tests/test_trafficdirector.cpp

@@ -5,6 +5,7 @@
 #include <ai/AIGraph.hpp>
 #include <objects/InstanceObject.hpp>
 #include <objects/CharacterObject.hpp>
+#include <render/ViewCamera.hpp>
 
 bool operator!=(const AIGraphNode* lhs, const glm::vec3 &rhs) { return lhs->position != rhs; }
 std::ostream &operator<<(std::ostream &os, const AIGraphNode* yt) { os << glm::to_string(yt->position); return os; }
@@ -68,8 +69,10 @@ BOOST_AUTO_TEST_CASE(test_available_nodes)
 	graph.createPathNodes(glm::vec3(), glm::quat(), path);
 	
 	TrafficDirector director(&graph, Global::get().e);
+
+	ViewCamera testCamera(glm::vec3(-5.f, -5.f, 0.f));
 	
-	auto open = director.findAvailableNodes(AIGraphNode::Pedestrian, glm::vec3(-5.f, -5.f, 0.f), 10.f);
+	auto open = director.findAvailableNodes(AIGraphNode::Pedestrian, testCamera, 10.f);
 	
 	std::vector<glm::vec3> expected {
 			{ 0.f,-10.f, 0.f },