Added scene network replication sample.

Source/Engine/Network/Connection.cpp

@@ -1380,6 +1380,7 @@ void Connection::OnPackagesReady()
     
     if (sceneFileName_.Empty())
     {
+        /// \todo Should not clear local nodes
         scene_->Clear();
         sceneLoaded_ = true;
         

Source/Samples/03_Sprites/Sprites.cpp

@@ -139,7 +139,6 @@ void Sprites::SubscribeToEvents()
 
 void Sprites::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/04_StaticScene/StaticScene.cpp

@@ -193,7 +193,6 @@ void StaticScene::SubscribeToEvents()
 
 void StaticScene::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/05_AnimatingScene/AnimatingScene.cpp

@@ -189,7 +189,6 @@ void AnimatingScene::MoveCamera(float timeStep)
 
 void AnimatingScene::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/06_SkeletalAnimation/SkeletalAnimation.cpp

@@ -232,7 +232,6 @@ void SkeletalAnimation::MoveCamera(float timeStep)
 
 void SkeletalAnimation::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/07_Billboards/Billboards.cpp

@@ -317,7 +317,6 @@ void Billboards::AnimateScene(float timeStep)
 
 void Billboards::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/08_Decals/Decals.cpp

@@ -162,7 +162,6 @@ void Decals::CreateUI()
     SharedPtr<Cursor> cursor(new Cursor(context_));
     cursor->SetStyleAuto(style);
     ui->SetCursor(cursor);
-
     // Set starting position of the cursor at the rendering window center
     Graphics* graphics = GetSubsystem<Graphics>();
     cursor->SetPosition(graphics->GetWidth() / 2, graphics->GetHeight() / 2);
@@ -310,7 +309,6 @@ bool Decals::Raycast(float maxDistance, Vector3& hitPos, Drawable*& hitDrawable)
 
 void Decals::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/09_MultipleViewports/MultipleViewports.cpp

@@ -24,7 +24,6 @@
 #include "CoreEvents.h"
 #include "Cursor.h"
 #include "DebugRenderer.h"
-#include "DecalSet.h"
 #include "Engine.h"
 #include "Font.h"
 #include "Graphics.h"
@@ -273,7 +272,6 @@ void MultipleViewports::MoveCamera(float timeStep)
 
 void MultipleViewports::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/10_RenderToTexture/RenderToTexture.cpp

@@ -275,7 +275,6 @@ void RenderToTexture::SubscribeToEvents()
 
 void RenderToTexture::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/11_Physics/Physics.cpp

@@ -276,7 +276,6 @@ void Physics::SpawnObject()
 
 void Physics::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/12_PhysicsStressTest/PhysicsStressTest.cpp

@@ -291,7 +291,6 @@ void PhysicsStressTest::SpawnObject()
 
 void PhysicsStressTest::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/13_Ragdolls/Ragdolls.cpp

@@ -282,7 +282,6 @@ void Ragdolls::SubscribeToEvents()
 
 void Ragdolls::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/15_Navigation/Navigation.cpp

@@ -367,7 +367,6 @@ bool Navigation::Raycast(float maxDistance, Vector3& hitPos, Drawable*& hitDrawa
 
 void Navigation::HandleUpdate(StringHash eventType, VariantMap& eventData)
 {
-    // Event parameters are always defined inside a namespace corresponding to the event's name
     using namespace Update;
 
     // Take the frame time step, which is stored as a float

Source/Samples/16_Chat/Chat.cpp

@@ -116,12 +116,17 @@ void Chat::CreateUI()
 
 void Chat::SubscribeToEvents()
 {
+    // Subscribe to UI element events
     SubscribeToEvent(textEdit_, E_TEXTFINISHED, HANDLER(Chat, HandleSend));
     SubscribeToEvent(sendButton_, E_RELEASED, HANDLER(Chat, HandleSend));
     SubscribeToEvent(connectButton_, E_RELEASED, HANDLER(Chat, HandleConnect));
     SubscribeToEvent(disconnectButton_, E_RELEASED, HANDLER(Chat, HandleDisconnect));
     SubscribeToEvent(startServerButton_, E_RELEASED, HANDLER(Chat, HandleStartServer));
+
+    // Subscribe to log messages so that we can pipe them to the chat window
     SubscribeToEvent(E_LOGMESSAGE, HANDLER(Chat, HandleLogMessage));
+    
+    // Subscribe to network events
     SubscribeToEvent(E_NETWORKMESSAGE, HANDLER(Chat, HandleNetworkMessage));
     SubscribeToEvent(E_SERVERCONNECTED, HANDLER(Chat, HandleConnectionStatus));
     SubscribeToEvent(E_SERVERDISCONNECTED, HANDLER(Chat, HandleConnectionStatus));

Source/Samples/16_Chat/Chat.h

@@ -54,7 +54,7 @@ private:
     void CreateUI();
     /// Subscribe to log message, UI and network events.
     void SubscribeToEvents();
-    /// Create a button.
+    /// Create a button to the button container.
     Button* CreateButton(const String& text, int width);
     /// Print chat text.
     void ShowChatText(const String& row);
@@ -80,7 +80,7 @@ private:
     SharedPtr<Text> chatHistoryText_;
     /// Button container element.
     SharedPtr<UIElement> buttonContainer_;
-    /// Line editor element.
+    /// Server address / chat message line editor element.
     SharedPtr<LineEdit> textEdit_;
     /// Send button.
     SharedPtr<Button> sendButton_;

Source/Samples/17_SceneReplication/CMakeLists.txt

@@ -0,0 +1,32 @@
+#
+# Copyright (c) 2008-2013 the Urho3D project.
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in
+# all copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+# THE SOFTWARE.
+#
+
+# Define target name
+set (TARGET_NAME 17_SceneReplication)
+
+# Define source files
+file (GLOB CPP_FILES *.cpp)
+file (GLOB H_FILES *.h)
+set (SOURCE_FILES ${CPP_FILES} ${H_FILES} ${COMMON_SAMPLE_H_FILES})
+
+# Setup target with resource copying
+setup_main_executable ()

Source/Samples/17_SceneReplication/SceneReplication.cpp

@@ -0,0 +1,499 @@
+//
+// Copyright (c) 2008-2013 the Urho3D project.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+
+#include "Button.h"
+#include "Camera.h"
+#include "CollisionShape.h"
+#include "Connection.h"
+#include "Controls.h"
+#include "CoreEvents.h"
+#include "Cursor.h"
+#include "Engine.h"
+#include "Font.h"
+#include "Graphics.h"
+#include "Input.h"
+#include "Light.h"
+#include "LineEdit.h"
+#include "Log.h"
+#include "Material.h"
+#include "Model.h"
+#include "Network.h"
+#include "NetworkEvents.h"
+#include "Octree.h"
+#include "PhysicsEvents.h"
+#include "PhysicsWorld.h"
+#include "Renderer.h"
+#include "RigidBody.h"
+#include "ResourceCache.h"
+#include "StaticModel.h"
+#include "Text.h"
+#include "UI.h"
+#include "UIEvents.h"
+#include "XMLFile.h"
+#include "Zone.h"
+
+#include "SceneReplication.h"
+
+#include "DebugNew.h"
+
+// UDP port we will use
+static const unsigned short SERVER_PORT = 2345;
+// Identifier for our custom remote event we use to tell the client which object they control
+static const StringHash E_CLIENTOBJECTID("ClientObjectID");
+// Identifier for the node ID parameter in the event data
+static const ShortStringHash P_ID("ID");
+
+// Control bits we define
+static const unsigned CTRL_FORWARD = 1;
+static const unsigned CTRL_BACK = 2;
+static const unsigned CTRL_LEFT = 4;
+static const unsigned CTRL_RIGHT = 8;
+
+// Expands to this example's entry-point
+DEFINE_APPLICATION_MAIN(SceneReplication)
+
+SceneReplication::SceneReplication(Context* context) :
+    Sample(context),
+    yaw_(0.0f),
+    pitch_(1.0f)
+{
+}
+
+void SceneReplication::Start()
+{
+    // Execute base class startup
+    Sample::Start();
+
+    // Create the scene content
+    CreateScene();
+    
+    // Create the UI content
+    CreateUI();
+    
+    // Setup the viewport for displaying the scene
+    SetupViewport();
+
+    // Hook up to necessary events
+    SubscribeToEvents();
+}
+
+void SceneReplication::CreateScene()
+{
+    scene_ = new Scene(context_);
+    
+    // Create the camera. Limit far clip distance to match the fog. Camera is created outside the scene so that network
+    // replication will not affect it (the scene will be cleared when connecting as a client)
+    cameraNode_ = new Node(context_);
+    Camera* camera = cameraNode_->CreateComponent<Camera>();
+    camera->SetFarClip(300.0f);
+    
+    // Set an initial position for the camera scene node above the plane
+    cameraNode_->SetPosition(Vector3(0.0f, 5.0f, 0.0f));
+}
+
+void SceneReplication::CreateUI()
+{
+    ResourceCache* cache = GetSubsystem<ResourceCache>();
+    UI* ui = GetSubsystem<UI>();
+    UIElement* root = ui->GetRoot();
+    XMLFile* uiStyle = cache->GetResource<XMLFile>("UI/DefaultStyle.xml");
+    // Set style to the UI root so that elements will inherit it
+    root->SetDefaultStyle(uiStyle);
+
+    // Create a Cursor UI element because we want to be able to hide and show it at will. When hidden, the mouse cursor will
+    // control the camera, and when visible, it can interact with the login UI
+    SharedPtr<Cursor> cursor(new Cursor(context_));
+    cursor->SetStyleAuto(uiStyle);
+    ui->SetCursor(cursor);
+    // Set starting position of the cursor at the rendering window center
+    Graphics* graphics = GetSubsystem<Graphics>();
+    cursor->SetPosition(graphics->GetWidth() / 2, graphics->GetHeight() / 2);
+    
+    // Construct the instructions text element
+    instructionsText_ = ui->GetRoot()->CreateChild<Text>();
+    instructionsText_->SetText(
+        "Use WASD keys to move and RMB to rotate view"
+    );
+    instructionsText_->SetFont(cache->GetResource<Font>("Fonts/Anonymous Pro.ttf"), 15);
+    // Position the text relative to the screen center
+    instructionsText_->SetHorizontalAlignment(HA_CENTER);
+    instructionsText_->SetVerticalAlignment(VA_CENTER);
+    instructionsText_->SetPosition(0, ui->GetRoot()->GetHeight() / 4);
+    // Hide until connected
+    instructionsText_->SetVisible(false);
+    
+    buttonContainer_ = root->CreateChild<UIElement>();
+    buttonContainer_->SetFixedSize(500, 20);
+    buttonContainer_->SetPosition(20, 20);
+    buttonContainer_->SetLayoutMode(LM_HORIZONTAL);
+    
+    textEdit_ = buttonContainer_->CreateChild<LineEdit>();
+    textEdit_->SetStyleAuto();
+    
+    connectButton_ = CreateButton("Connect", 90);
+    disconnectButton_ = CreateButton("Disconnect", 100);
+    startServerButton_ = CreateButton("Start Server", 110);
+    
+    UpdateButtons();
+}
+
+void SceneReplication::SetupViewport()
+{
+    Renderer* renderer = GetSubsystem<Renderer>();
+    
+    // Set up a viewport to the Renderer subsystem so that the 3D scene can be seen
+    SharedPtr<Viewport> viewport(new Viewport(context_, scene_, cameraNode_->GetComponent<Camera>()));
+    renderer->SetViewport(0, viewport);
+}
+
+void SceneReplication::SubscribeToEvents()
+{
+    // Subscribe to fixed timestep physics updates for setting or applying controls
+    SubscribeToEvent(E_PHYSICSPRESTEP, HANDLER(SceneReplication, HandlePhysicsPreStep));
+    
+    // Subscribe HandlePostUpdate() method for processing update events. Subscribe to PostUpdate instead
+    // of the usual Update so that physics simulation has already proceeded for the frame, and can
+    // accurately follow the object with the camera
+    SubscribeToEvent(E_POSTUPDATE, HANDLER(SceneReplication, HandlePostUpdate));
+    
+    // Subscribe to button actions
+    SubscribeToEvent(connectButton_, E_RELEASED, HANDLER(SceneReplication, HandleConnect));
+    SubscribeToEvent(disconnectButton_, E_RELEASED, HANDLER(SceneReplication, HandleDisconnect));
+    SubscribeToEvent(startServerButton_, E_RELEASED, HANDLER(SceneReplication, HandleStartServer));
+
+    // Subscribe to network events
+    SubscribeToEvent(E_SERVERCONNECTED, HANDLER(SceneReplication, HandleConnectionStatus));
+    SubscribeToEvent(E_SERVERDISCONNECTED, HANDLER(SceneReplication, HandleConnectionStatus));
+    SubscribeToEvent(E_CONNECTFAILED, HANDLER(SceneReplication, HandleConnectionStatus));
+    SubscribeToEvent(E_CLIENTCONNECTED, HANDLER(SceneReplication, HandleClientConnected));
+    SubscribeToEvent(E_CLIENTDISCONNECTED, HANDLER(SceneReplication, HandleClientDisconnected));
+    // This is a custom event, sent from the server to the client. It tells the node ID of the object the client should control
+    SubscribeToEvent(E_CLIENTOBJECTID, HANDLER(SceneReplication, HandleClientObjectID));
+}
+
+Button* SceneReplication::CreateButton(const String& text, int width)
+{
+    ResourceCache* cache = GetSubsystem<ResourceCache>();
+    Font* font = cache->GetResource<Font>("Fonts/Anonymous Pro.ttf");
+    
+    Button* button = buttonContainer_->CreateChild<Button>();
+    button->SetStyleAuto();
+    button->SetFixedWidth(width);
+    
+    Text* buttonText = button->CreateChild<Text>();
+    buttonText->SetFont(font, 12);
+    buttonText->SetAlignment(HA_CENTER, VA_CENTER);
+    buttonText->SetText(text);
+    
+    return button;
+}
+
+void SceneReplication::UpdateButtons()
+{
+    Network* network = GetSubsystem<Network>();
+    Connection* serverConnection = network->GetServerConnection();
+    bool serverRunning = network->IsServerRunning();
+    
+    // Show and hide buttons so that eg. Connect and Disconnect are never shown at the same time
+    connectButton_->SetVisible(!serverConnection && !serverRunning);
+    disconnectButton_->SetVisible(serverConnection || serverRunning);
+    startServerButton_->SetVisible(!serverConnection && !serverRunning);
+    textEdit_->SetVisible(!serverConnection && !serverRunning);
+}
+
+Node* SceneReplication::CreateControllableObject()
+{
+    ResourceCache* cache = GetSubsystem<ResourceCache>();
+    
+    // Create the scene node & visual representation
+    Node* ballNode = scene_->CreateChild("Ball");
+    ballNode->SetPosition(Vector3(Random(40.0f) - 20.0f, 5.0f, Random(40.0f) - 20.0f));
+    ballNode->SetScale(0.5f);
+    StaticModel* ballObject = ballNode->CreateComponent<StaticModel>();
+    ballObject->SetModel(cache->GetResource<Model>("Models/Sphere.mdl"));
+    ballObject->SetMaterial(cache->GetResource<Material>("Materials/StoneSmall.xml"));
+    
+    // Create the physics components
+    RigidBody* body = ballNode->CreateComponent<RigidBody>();
+    body->SetMass(1.0f);
+    body->SetFriction(1.0f);
+    // In addition to friction, use motion damping so that the ball can not accelerate limitlessly
+    body->SetLinearDamping(0.5f);
+    body->SetAngularDamping(0.5f);
+    CollisionShape* shape = ballNode->CreateComponent<CollisionShape>();
+    shape->SetSphere(1.0f);
+    
+    // Create a random colored point light at the ball so that can see better where is going
+    Light* light = ballNode->CreateComponent<Light>();
+    light->SetRange(3.0f);
+    light->SetColor(Color(0.5f + (Rand() & 1) * 0.5f, 0.5f + (Rand() & 1) * 0.5f, 0.5f + (Rand() & 1) * 0.5f));
+    
+    return ballNode;
+}
+
+void SceneReplication::MoveCamera()
+{
+    // Right mouse button controls mouse cursor visibility: hide when pressed
+    UI* ui = GetSubsystem<UI>();
+    Input* input = GetSubsystem<Input>();
+    ui->GetCursor()->SetVisible(!input->GetMouseButtonDown(MOUSEB_RIGHT));
+    
+    // Mouse sensitivity as degrees per pixel
+    const float MOUSE_SENSITIVITY = 0.1f;
+    
+    // Use this frame's mouse motion to adjust camera node yaw and pitch. Clamp the pitch and only move the camera
+    // when the cursor is hidden
+    if (!ui->GetCursor()->IsVisible())
+    {
+        IntVector2 mouseMove = input->GetMouseMove();
+        yaw_ += MOUSE_SENSITIVITY * mouseMove.x_;
+        pitch_ += MOUSE_SENSITIVITY * mouseMove.y_;
+        pitch_ = Clamp(pitch_, 1.0f, 90.0f);
+    }
+    
+    // Construct new orientation for the camera scene node from yaw and pitch. Roll is fixed to zero
+    cameraNode_->SetRotation(Quaternion(pitch_, yaw_, 0.0f));
+    
+    // Only move the camera / show instructions if we have a controllable object
+    bool showInstructions = false;
+    if (clientObjectID_)
+    {
+        Node* ballNode = scene_->GetNode(clientObjectID_);
+        if (ballNode)
+        {
+            const float CAMERA_DISTANCE = 5.0f;
+            
+            // Move camera some distance away from the ball
+            cameraNode_->SetPosition(ballNode->GetPosition() + cameraNode_->GetRotation() * Vector3::BACK * CAMERA_DISTANCE);
+            showInstructions = true;
+        }
+    }
+    
+    instructionsText_->SetVisible(showInstructions);
+}
+
+void SceneReplication::HandlePostUpdate(StringHash eventType, VariantMap& eventData)
+{
+    // We only rotate the camera according to mouse movement since last frame, so do not need the time step
+    MoveCamera();
+}
+
+void SceneReplication::HandlePhysicsPreStep(StringHash eventType, VariantMap& eventData)
+{
+    // This function is different on the client and server. The client collects controls (WASD controls + yaw angle)
+    // and sets them to its server connection object, so that they will be sent to the server automatically at a
+    // fixed rate, by default 30 FPS. The server will actually apply the controls (authoritative simulation.)
+    Network* network = GetSubsystem<Network>();
+    Connection* serverConnection = network->GetServerConnection();
+    
+    // Client: collect controls
+    if (serverConnection)
+    {
+        UI* ui = GetSubsystem<UI>();
+        Input* input = GetSubsystem<Input>();
+        Controls controls;
+        
+        // Assume buttons are not pressed, copy yaw
+        controls.buttons_ = 0;
+        controls.yaw_ = yaw_;
+        
+        // Only apply WASD controls if there is no focused UI element
+        if (!ui->GetFocusElement())
+        {
+            if (input->GetKeyDown('W'))
+                controls.buttons_ |= CTRL_FORWARD;
+            if (input->GetKeyDown('S'))
+                controls.buttons_ |= CTRL_BACK;
+            if (input->GetKeyDown('A'))
+                controls.buttons_ |= CTRL_LEFT;
+            if (input->GetKeyDown('D'))
+                controls.buttons_ |= CTRL_RIGHT;
+        }
+        
+        serverConnection->SetControls(controls);
+        // In case the server wants to do position-based interest management using the NetworkPriority components, we should also
+        // tell it our observer (camera) position. In this sample it is not in use, but eg. the NinjaSnowWar game uses it
+        serverConnection->SetPosition(cameraNode_->GetPosition());
+    }
+    // Server: apply controls to client objects
+    else if (network->IsServerRunning())
+    {
+        const Vector<SharedPtr<Connection> >& connections = network->GetClientConnections();
+        
+        for (unsigned i = 0; i < connections.Size(); ++i)
+        {
+            Connection* connection = connections[i];
+            // Get the object this connection is controlling
+            Node* ballNode = serverObjects_[connection];
+            if (!ballNode)
+                continue;
+            
+            RigidBody* body = ballNode->GetComponent<RigidBody>();
+            
+            // Get the last controls sent by the client
+            const Controls& controls = connection->GetControls();
+            // Torque is relative to the forward vector
+            Quaternion rotation(0.0f, controls.yaw_, 0.0f);
+            
+            const float MOVE_TORQUE = 3.0f;
+            
+            // Movement torque is applied before each simulation step, which happen at 60 FPS. This makes the simulation
+            // independent from rendering framerate. We could also apply forces (which would enable in-air control),
+            // but want to emphasize that it's a ball which should only control its motion by rolling along the ground
+            if (controls.buttons_ & CTRL_FORWARD)
+                body->ApplyTorque(rotation * Vector3::RIGHT * MOVE_TORQUE);
+            if (controls.buttons_ & CTRL_BACK)
+                body->ApplyTorque(rotation * Vector3::LEFT * MOVE_TORQUE);
+            if (controls.buttons_ & CTRL_LEFT)
+                body->ApplyTorque(rotation * Vector3::FORWARD * MOVE_TORQUE);
+            if (controls.buttons_ & CTRL_RIGHT)
+                body->ApplyTorque(rotation * Vector3::BACK * MOVE_TORQUE);
+        }
+    }
+}
+
+void SceneReplication::HandleConnect(StringHash eventType, VariantMap& eventData)
+{
+    Network* network = GetSubsystem<Network>();
+    String address = textEdit_->GetText().Trimmed();
+    if (address.Empty())
+        address = "localhost"; // Use localhost to connect if nothing else specified
+    
+    // Connect to server, specify scene to use as a client for replication
+    clientObjectID_ = 0; // Reset own object ID from possible previous connection
+    network->Connect(address, SERVER_PORT, scene_);
+    
+    UpdateButtons();
+}
+
+void SceneReplication::HandleDisconnect(StringHash eventType, VariantMap& eventData)
+{
+    Network* network = GetSubsystem<Network>();
+    Connection* serverConnection = network->GetServerConnection();
+    // If we were connected to server, disconnect
+    if (serverConnection)
+    {
+        serverConnection->Disconnect();
+        scene_->Clear();
+        clientObjectID_ = 0;
+    }
+    // Or if we were running a server, stop it
+    else if (network->IsServerRunning())
+    {
+        network->StopServer();
+        scene_->Clear();
+    }
+    
+    
+    UpdateButtons();
+}
+
+void SceneReplication::HandleStartServer(StringHash eventType, VariantMap& eventData)
+{
+    Network* network = GetSubsystem<Network>();
+    network->StartServer(SERVER_PORT);
+    
+    // Create scene content on the server only
+    ResourceCache* cache = GetSubsystem<ResourceCache>();
+    
+    // Create octree and physics world with default settings
+    scene_->CreateComponent<Octree>();
+    scene_->CreateComponent<PhysicsWorld>();
+    
+    // Create a Zone component for ambient lighting & fog control
+    Node* zoneNode = scene_->CreateChild("Zone");
+    Zone* zone = zoneNode->CreateComponent<Zone>();
+    zone->SetBoundingBox(BoundingBox(-1000.0f, 1000.0f));
+    zone->SetAmbientColor(Color(0.1f, 0.1f, 0.1f));
+    zone->SetFogStart(100.0f);
+    zone->SetFogEnd(300.0f);
+    
+    // Create a directional light without shadows
+    Node* lightNode = scene_->CreateChild("DirectionalLight");
+    lightNode->SetDirection(Vector3(0.5f, -1.0f, 0.5f));
+    Light* light = lightNode->CreateComponent<Light>();
+    light->SetLightType(LIGHT_DIRECTIONAL);
+    light->SetColor(Color(0.2f, 0.2f, 0.2f));
+    light->SetSpecularIntensity(1.0f);
+    
+    // Create a "floor" consisting of several tiles. Make the tiles physical but leave small cracks between them
+    for (int y = -20; y <= 20; ++y)
+    {
+        for (int x = -20; x <= 20; ++x)
+        {
+            Node* floorNode = scene_->CreateChild("FloorTile");
+            floorNode->SetPosition(Vector3(x * 20.2f, -0.5f, y * 20.2f));
+            floorNode->SetScale(Vector3(20.0f, 1.0f, 20.0f));
+            StaticModel* floorObject = floorNode->CreateComponent<StaticModel>();
+            floorObject->SetModel(cache->GetResource<Model>("Models/Box.mdl"));
+            floorObject->SetMaterial(cache->GetResource<Material>("Materials/Stone.xml"));
+            
+            RigidBody* body = floorNode->CreateComponent<RigidBody>();
+            body->SetFriction(1.0f);
+            CollisionShape* shape = floorNode->CreateComponent<CollisionShape>();
+            shape->SetBox(Vector3::ONE);
+        }
+    }
+    
+    UpdateButtons();
+}
+
+void SceneReplication::HandleConnectionStatus(StringHash eventType, VariantMap& eventData)
+{
+    UpdateButtons();
+}
+
+void SceneReplication::HandleClientConnected(StringHash eventType, VariantMap& eventData)
+{
+    using namespace ClientConnected;
+    
+    // When a client connects, assign to scene to begin scene replication
+    Connection* newConnection = (Connection*)eventData[P_CONNECTION].GetPtr();
+    newConnection->SetScene(scene_);
+    
+    // Then create a controllable object for that client
+    Node* newObject = CreateControllableObject();
+    serverObjects_[newConnection] = newObject;
+    
+    // Finally send the object's node ID using a remote event
+    VariantMap remoteEventData;
+    remoteEventData[P_ID] = newObject->GetID();
+    newConnection->SendRemoteEvent(E_CLIENTOBJECTID, true, remoteEventData);
+}
+
+void SceneReplication::HandleClientDisconnected(StringHash eventType, VariantMap& eventData)
+{
+    using namespace ClientConnected;
+    
+    // When a client disconnects, remove the controlled object
+    Connection* connection = (Connection*)eventData[P_CONNECTION].GetPtr();
+    Node* object = serverObjects_[connection];
+    if (object)
+        object->Remove();
+    
+    serverObjects_.Erase(connection);
+}
+
+void SceneReplication::HandleClientObjectID(StringHash eventType, VariantMap& eventData)
+{
+    clientObjectID_ = eventData[P_ID].GetUInt();
+}

Source/Samples/17_SceneReplication/SceneReplication.h

@@ -0,0 +1,116 @@
+//
+// Copyright (c) 2008-2013 the Urho3D project.
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in
+// all copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+//
+
+#pragma once
+
+#include "Sample.h"
+#include "Scene.h"
+
+namespace Urho3D
+{
+    class Button;
+    class Connection;
+    class Text;
+    class UIElement;
+}
+
+// All Urho3D classes reside in namespace Urho3D
+using namespace Urho3D;
+
+/// Scene network replication example.
+/// This sample demonstrates:
+///     - Creating a scene in which network clients can join;
+///     - Giving each client an object to control and sending the controls from the clients to the server,
+///       where the authoritative simulation happens;
+///     - Controlling a physics object's movement by applying forces;
+class SceneReplication : public Sample
+{
+    OBJECT(SceneReplication);
+
+public:
+    /// Construct.
+    SceneReplication(Context* context);
+
+    /// Setup after engine initialization and before running the main loop.
+    virtual void Start();
+
+private:
+    /// Construct the scene content.
+    void CreateScene();
+    /// Construct instruction text and the login / start server UI.
+    void CreateUI();
+    /// Set up viewport.
+    void SetupViewport();
+    /// Subscribe to update, UI and network events.
+    void SubscribeToEvents();
+    /// Create a button to the button container.
+    Button* CreateButton(const String& text, int width);
+    /// Update visibility of buttons according to connection and server status.
+    void UpdateButtons();
+    /// Create a controllable ball object and return its scene node.
+    Node* CreateControllableObject();
+    /// Read input and move the camera.
+    void MoveCamera();
+    /// Handle the physics world pre-step event.
+    void HandlePhysicsPreStep(StringHash eventType, VariantMap& eventData);
+    /// Handle the logic post-update event.
+    void HandlePostUpdate(StringHash eventType, VariantMap& eventData);
+    /// Handle pressing the connect button.
+    void HandleConnect(StringHash eventType, VariantMap& eventData);
+    /// Handle pressing the disconnect button.
+    void HandleDisconnect(StringHash eventType, VariantMap& eventData);
+    /// Handle pressing the start server button.
+    void HandleStartServer(StringHash eventType, VariantMap& eventData);
+    /// Handle connection status change (just update the buttons that should be shown.)
+    void HandleConnectionStatus(StringHash eventType, VariantMap& eventData);
+    /// Handle a client connecting to the server.
+    void HandleClientConnected(StringHash eventType, VariantMap& eventData);
+    /// Handle a client disconnecting from the server.
+    void HandleClientDisconnected(StringHash eventType, VariantMap& eventData);
+    /// Handle remote event from server which tells our controlled object node ID.
+    void HandleClientObjectID(StringHash eventType, VariantMap& eventData);
+    
+    /// Scene.
+    SharedPtr<Scene> scene_;
+    /// Camera scene node.
+    SharedPtr<Node> cameraNode_;
+    /// Mapping from client connections to controllable objects.
+    HashMap<Connection*, WeakPtr<Node> > serverObjects_;
+    /// Button container element.
+    SharedPtr<UIElement> buttonContainer_;
+    /// Server address line editor element.
+    SharedPtr<LineEdit> textEdit_;
+    /// Connect button.
+    SharedPtr<Button> connectButton_;
+    /// Disconnect button.
+    SharedPtr<Button> disconnectButton_;
+    /// Start server button.
+    SharedPtr<Button> startServerButton_;
+    /// Instructions text.
+    SharedPtr<Text> instructionsText_;
+    /// ID of own controllable object (client only.)
+    unsigned clientObjectID_;
+    /// Camera yaw angle.
+    float yaw_;
+    /// Camera pitch angle.
+    float pitch_;
+};

Source/Samples/CMakeLists.txt

@@ -58,3 +58,4 @@ add_subdirectory (13_Ragdolls)
 add_subdirectory (14_SoundEffects)
 add_subdirectory (15_Navigation)
 add_subdirectory (16_Chat)
+add_subdirectory (17_SceneReplication)