urho3d/bin/Data/Scripts/39_CrowdNavigation.as

// CrowdNavigation example.
// This sample demonstrates:
//     - Generating a dynamic navigation mesh into the scene
//     - Performing path queries to the navigation mesh
//     - Adding and removing obstacles/agents at runtime
//     - Raycasting drawable components
//     - Crowd movement management
//     - Accessing crowd agents with the crowd manager
//     - Using off-mesh connections to make boxes climbable
//     - Using agents to simulate moving obstacles

#include "Scripts/Utilities/Sample.as"

const String INSTRUCTION("instructionText");

bool useStreaming = false;
// Used for streaming only
const int STREAMING_DISTANCE = 2;
Array<VectorBuffer> navigationTilesData;
Array<IntVector2> navigationTilesIdx;
Array<IntVector2> addedTiles;

void Start()
{
    // Execute the common startup for samples
    SampleStart();

    // Create the scene content
    CreateScene();

    // Create the UI content
    CreateUI();

    // Setup the viewport for displaying the scene
    SetupViewport();

    // Set the mouse mode to use in the sample
    SampleInitMouseMode(MM_RELATIVE);

    // Hook up to the frame update and render post-update events
    SubscribeToEvents();
}

void CreateScene()
{
    scene_ = Scene();

    // Create octree, use default volume (-1000, -1000, -1000) to (1000, 1000, 1000)
    // Also create a DebugRenderer component so that we can draw debug geometry
    scene_.CreateComponent("Octree");
    scene_.CreateComponent("DebugRenderer");

    // Create scene node & StaticModel component for showing a static plane
    Node@ planeNode = scene_.CreateChild("Plane");
    planeNode.scale = Vector3(100.0f, 1.0f, 100.0f);
    StaticModel@ planeObject = planeNode.CreateComponent("StaticModel");
    planeObject.model = cache.GetResource("Model", "Models/Plane.mdl");
    planeObject.material = cache.GetResource("Material", "Materials/StoneTiled.xml");

    // Create a Zone component for ambient lighting & fog control
    Node@ zoneNode = scene_.CreateChild("Zone");
    Zone@ zone = zoneNode.CreateComponent("Zone");
    zone.boundingBox = BoundingBox(-1000.0f, 1000.0f);
    zone.ambientColor = Color(0.15f, 0.15f, 0.15f);
    zone.fogColor = Color(0.5f, 0.5f, 0.7f);
    zone.fogStart = 100.0f;
    zone.fogEnd = 300.0f;

    // Create a directional light to the world. Enable cascaded shadows on it
    Node@ lightNode = scene_.CreateChild("DirectionalLight");
    lightNode.direction = Vector3(0.6f, -1.0f, 0.8f);
    Light@ light = lightNode.CreateComponent("Light");
    light.lightType = LIGHT_DIRECTIONAL;
    light.castShadows = true;
    light.shadowBias = BiasParameters(0.00025f, 0.5f);
    // Set cascade splits at 10, 50 and 200 world units, fade shadows out at 80% of maximum shadow distance
    light.shadowCascade = CascadeParameters(10.0f, 50.0f, 200.0f, 0.0f, 0.8f);

    // Create randomly sized boxes. If boxes are big enough, make them occluders. Occluders will be software rasterized before
    // rendering to a low-resolution depth-only buffer to test the objects in the view frustum for visibility
    Node@ boxGroup = scene_.CreateChild("Boxes");
    for (uint i = 0; i < 20; ++i)
    {
        Node@ boxNode = boxGroup.CreateChild("Box");
        float size = 1.0f + Random(10.0f);
        boxNode.position = Vector3(Random(80.0f) - 40.0f, size * 0.5f, Random(80.0f) - 40.0f);
        boxNode.SetScale(size);
        StaticModel@ boxObject = boxNode.CreateComponent("StaticModel");
        boxObject.model = cache.GetResource("Model", "Models/Box.mdl");
        boxObject.material = cache.GetResource("Material", "Materials/Stone.xml");
        boxObject.castShadows = true;
        if (size >= 3.0f)
            boxObject.occluder = true;
    }

    // Create a DynamicNavigationMesh component to the scene root
    DynamicNavigationMesh@ navMesh = scene_.CreateComponent("DynamicNavigationMesh");
    // Set small tiles to show navigation mesh streaming
    navMesh.tileSize = 32;
    // Enable drawing debug geometry for obstacles and off-mesh connections
    navMesh.drawObstacles = true;
    navMesh.drawOffMeshConnections = true;
    // Set the agent height large enough to exclude the layers under boxes
    navMesh.agentHeight = 10;
    // Set nav mesh cell height to minimum (allows agents to be grounded)
    navMesh.cellHeight = 0.05f;
    // Create a Navigable component to the scene root. This tags all of the geometry in the scene as being part of the
    // navigation mesh. By default this is recursive, but the recursion could be turned off from Navigable
    scene_.CreateComponent("Navigable");
    // Add padding to the navigation mesh in Y-direction so that we can add objects on top of the tallest boxes
    // in the scene and still update the mesh correctly
    navMesh.padding = Vector3(0.0f, 10.0f, 0.0f);
    // Now build the navigation geometry. This will take some time. Note that the navigation mesh will prefer to use
    // physics geometry from the scene nodes, as it often is simpler, but if it can not find any (like in this example)
    // it will use renderable geometry instead
    navMesh.Build();

    // Create an off-mesh connection to each box to make it climbable (tiny boxes are skipped). A connection is built from 2 nodes.
    // Note that OffMeshConnections must be added before building the navMesh, but as we are adding Obstacles next, tiles will be automatically rebuilt.
    // Creating connections post-build here allows us to use FindNearestPoint() to procedurally set accurate positions for the connection
    CreateBoxOffMeshConnections(navMesh, boxGroup);

    // Create some mushrooms as obstacles. Note that obstacles are non-walkable areas
    for (uint i = 0; i < 100; ++i)
        CreateMushroom(Vector3(Random(90.0f) - 45.0f, 0.0f, Random(90.0f) - 45.0f));

    // Create a CrowdManager component to the scene root (mandatory for crowd agents)
    CrowdManager@ crowdManager = scene_.CreateComponent("CrowdManager");
    CrowdObstacleAvoidanceParams params = crowdManager.GetObstacleAvoidanceParams(0);
    // Set the params to "High (66)" setting
    params.velBias = 0.5f;
    params.adaptiveDivs = 7;
    params.adaptiveRings = 3;
    params.adaptiveDepth = 3;
    crowdManager.SetObstacleAvoidanceParams(0, params);

    // Create some movable barrels. We create them as crowd agents, as for moving entities it is less expensive and more convenient than using obstacles
    CreateMovingBarrels(navMesh);

    // Create Jack node as crowd agent
    SpawnJack(Vector3(-5.0f, 0, 20.0f), scene_.CreateChild("Jacks"));

    // Create the camera. Limit far clip distance to match the fog. Note: now we actually create the camera node outside
    // the scene, because we want it to be unaffected by scene load / save
    cameraNode = Node();
    Camera@ camera = cameraNode.CreateComponent("Camera");
    camera.farClip = 300.0f;

    // Set an initial position for the camera scene node above the plane and looking down
    cameraNode.position = Vector3(0.0f, 50.0f, 0.0f);
    pitch = 80.0f;
    cameraNode.rotation = Quaternion(pitch, yaw, 0.0f);
}

void CreateUI()
{
    // 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 will point the raycast target
    XMLFile@ style = cache.GetResource("XMLFile", "UI/DefaultStyle.xml");
    Cursor@ cursor = Cursor();
    cursor.SetStyleAuto(style);
    ui.cursor = cursor;
    // Set starting position of the cursor at the rendering window center
    cursor.SetPosition(graphics.width / 2, graphics.height / 2);

    // Construct new Text object, set string to display and font to use
    Text@ instructionText = ui.root.CreateChild("Text", INSTRUCTION);
    instructionText.text =
        "Use WASD keys to move, RMB to rotate view\n"
        "LMB to set destination, SHIFT+LMB to spawn a Jack\n"
        "MMB or O key to add obstacles or remove obstacles/agents\n"
        "F5 to save scene, F7 to load\n"
        "Tab to toggle navigation mesh streaming\n"
        "Space to toggle debug geometry\n"
        "F12 to toggle this instruction text";
    instructionText.SetFont(cache.GetResource("Font", "Fonts/Anonymous Pro.ttf"), 15);
    // The text has multiple rows. Center them in relation to each other
    instructionText.textAlignment = HA_CENTER;

    // Position the text relative to the screen center
    instructionText.horizontalAlignment = HA_CENTER;
    instructionText.verticalAlignment = VA_CENTER;
    instructionText.SetPosition(0, ui.root.height / 4);
}

void SetupViewport()
{
    // Set up a viewport to the Renderer subsystem so that the 3D scene can be seen
    Viewport@ viewport = Viewport(scene_, cameraNode.GetComponent("Camera"));
    renderer.viewports[0] = viewport;
}

void SubscribeToEvents()
{
    // Subscribe HandleUpdate() function for processing update events
    SubscribeToEvent("Update", "HandleUpdate");

    // Subscribe HandlePostRenderUpdate() function for processing the post-render update event, during which we request debug geometry
    SubscribeToEvent("PostRenderUpdate", "HandlePostRenderUpdate");

    // Subscribe HandleCrowdAgentFailure() function for resolving invalidation issues with agents, during which we
    // use a larger extents for finding a point on the navmesh to fix the agent's position
    SubscribeToEvent("CrowdAgentFailure", "HandleCrowdAgentFailure");

    // Subscribe HandleCrowdAgentReposition() function for controlling the animation
    SubscribeToEvent("CrowdAgentReposition", "HandleCrowdAgentReposition");

    // Subscribe HandleCrowdAgentFormation() function for positioning agent into a formation
    SubscribeToEvent("CrowdAgentFormation", "HandleCrowdAgentFormation");
}

void CreateMushroom(const Vector3& pos)
{
    Node@ mushroomNode = scene_.CreateChild("Mushroom");
    mushroomNode.position = pos;
    mushroomNode.rotation = Quaternion(0.0f, Random(360.0f), 0.0f);
    mushroomNode.SetScale(2.0f + Random(0.5f));
    StaticModel@ mushroomObject = mushroomNode.CreateComponent("StaticModel");
    mushroomObject.model = cache.GetResource("Model", "Models/Mushroom.mdl");
    mushroomObject.material = cache.GetResource("Material", "Materials/Mushroom.xml");
    mushroomObject.castShadows = true;

    // Create the navigation Obstacle component and set its height & radius proportional to scale
    Obstacle@ obstacle = mushroomNode.CreateComponent("Obstacle");
    obstacle.radius = mushroomNode.scale.x;
    obstacle.height = mushroomNode.scale.y;
}

void SpawnJack(const Vector3& pos, Node@ jackGroup)
{
    Node@ jackNode = jackGroup.CreateChild("Jack");
    jackNode.position = pos;
    AnimatedModel@ modelObject = jackNode.CreateComponent("AnimatedModel");
    modelObject.model = cache.GetResource("Model", "Models/Jack.mdl");
    modelObject.material = cache.GetResource("Material", "Materials/Jack.xml");
    modelObject.castShadows = true;
    jackNode.CreateComponent("AnimationController");

    // Create a CrowdAgent component and set its height and realistic max speed/acceleration. Use default radius
    CrowdAgent@ agent = jackNode.CreateComponent("CrowdAgent");
    agent.height = 2.0f;
    agent.maxSpeed = 3.0f;
    agent.maxAccel = 5.0f;
}

void CreateBoxOffMeshConnections(DynamicNavigationMesh@ navMesh, Node@ boxGroup)
{
    Array<Node@>@ boxes = boxGroup.GetChildren();
    for (uint i=0; i < boxes.length; ++i)
    {
        Node@ box = boxes[i];
        Vector3 boxPos = box.position;
        float boxHalfSize = box.scale.x / 2;

        // Create 2 empty nodes for the start & end points of the connection. Note that order matters only when using one-way/unidirectional connection.
        Node@ connectionStart = box.CreateChild("ConnectionStart");
        connectionStart.worldPosition = navMesh.FindNearestPoint(boxPos + Vector3(boxHalfSize, -boxHalfSize, 0)); // Base of box
        Node@ connectionEnd = connectionStart.CreateChild("ConnectionEnd");
        connectionEnd.worldPosition = navMesh.FindNearestPoint(boxPos + Vector3(boxHalfSize, boxHalfSize, 0)); // Top of box

        // Create the OffMeshConnection component to one node and link the other node
        OffMeshConnection@ connection = connectionStart.CreateComponent("OffMeshConnection");
        connection.endPoint = connectionEnd;
    }
}

void CreateMovingBarrels(DynamicNavigationMesh@ navMesh)
{
    Node@ barrel = scene_.CreateChild("Barrel");
    StaticModel@ model = barrel.CreateComponent("StaticModel");
    model.model = cache.GetResource("Model", "Models/Cylinder.mdl");
    Material@ material = cache.GetResource("Material", "Materials/StoneTiled.xml");
    model.material = material;
    material.textures[TU_DIFFUSE] = cache.GetResource("Texture2D", "Textures/TerrainDetail2.dds");
    model.castShadows = true;
    for (uint i = 0;  i < 20; ++i)
    {
        Node@ clone = barrel.Clone();
        float size = 0.5 + Random(1);
        clone.scale = Vector3(size / 1.5, size * 2.0, size / 1.5);
        clone.position = navMesh.FindNearestPoint(Vector3(Random(80.0) - 40.0, size * 0.5 , Random(80.0) - 40.0));
        CrowdAgent@ agent = clone.CreateComponent("CrowdAgent");
        agent.radius = clone.scale.x * 0.5f;
        agent.height = size;
        agent.navigationQuality = NAVIGATIONQUALITY_LOW;
    }
    barrel.Remove();
}

void SetPathPoint(bool spawning)
{
    Vector3 hitPos;
    Drawable@ hitDrawable;

    if (Raycast(250.0f, hitPos, hitDrawable))
    {
        DynamicNavigationMesh@ navMesh = scene_.GetComponent("DynamicNavigationMesh");
        Vector3 pathPos = navMesh.FindNearestPoint(hitPos, Vector3(1.0f, 1.0f, 1.0f));
        Node@ jackGroup = scene_.GetChild("Jacks");
        if (spawning)
            // Spawn a jack at the target position
            SpawnJack(pathPos, jackGroup);
        else
            // Set crowd agents target position
            cast<CrowdManager>(scene_.GetComponent("CrowdManager")).SetCrowdTarget(pathPos, jackGroup);
    }
}

void AddOrRemoveObject()
{
    // Raycast and check if we hit a mushroom node. If yes, remove it, if no, create a new one
    Vector3 hitPos;
    Drawable@ hitDrawable;

    if (Raycast(250.0f, hitPos, hitDrawable))
    {
        Node@ hitNode = hitDrawable.node;

        // Note that navmesh rebuild happens when the Obstacle component is removed
        if (hitNode.name == "Mushroom")
            hitNode.Remove();
        else if (hitNode.name == "Jack")
            hitNode.Remove();
        else
            CreateMushroom(hitPos);
    }
}

bool Raycast(float maxDistance, Vector3& hitPos, Drawable@& hitDrawable)
{
    hitDrawable = null;

    IntVector2 pos = ui.cursorPosition;
    // Check the cursor is visible and there is no UI element in front of the cursor
    if (!ui.cursor.visible || ui.GetElementAt(pos, true) !is null)
        return false;

    Camera@ camera = cameraNode.GetComponent("Camera");
    Ray cameraRay = camera.GetScreenRay(float(pos.x) / graphics.width, float(pos.y) / graphics.height);
    // Pick only geometry objects, not eg. zones or lights, only get the first (closest) hit
    // Note the convenience accessor to scene's Octree component
    RayQueryResult result = scene_.octree.RaycastSingle(cameraRay, RAY_TRIANGLE, maxDistance, DRAWABLE_GEOMETRY);
    if (result.drawable !is null)
    {
        hitPos = result.position;
        hitDrawable = result.drawable;
        return true;
    }

    return false;
}

void MoveCamera(float timeStep)
{
    input.mouseVisible = input.mouseMode != MM_RELATIVE;
    bool mouseDown = input.mouseButtonDown[MOUSEB_RIGHT];

    // Override the MM_RELATIVE mouse grabbed settings, to allow interaction with UI
    input.mouseGrabbed = mouseDown;

    // Right mouse button controls mouse cursor visibility: hide when pressed
    ui.cursor.visible = !mouseDown;

    // Do not move if the UI has a focused element (the console)
    if (ui.focusElement !is null)
        return;

    // Movement speed as world units per second
    const float MOVE_SPEED = 20.0f;
    // 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 between -90 and 90 degrees
    // Only move the camera when the cursor is hidden
    if (!ui.cursor.visible)
    {
        IntVector2 mouseMove = input.mouseMove;
        yaw += MOUSE_SENSITIVITY * mouseMove.x;
        pitch += MOUSE_SENSITIVITY * mouseMove.y;
        pitch = Clamp(pitch, -90.0f, 90.0f);

        // Construct new orientation for the camera scene node from yaw and pitch. Roll is fixed to zero
        cameraNode.rotation = Quaternion(pitch, yaw, 0.0f);
    }

    // Read WASD keys and move the camera scene node to the corresponding direction if they are pressed
    if (input.keyDown[KEY_W])
        cameraNode.Translate(Vector3::FORWARD * MOVE_SPEED * timeStep);
    if (input.keyDown[KEY_S])
        cameraNode.Translate(Vector3::BACK * MOVE_SPEED * timeStep);
    if (input.keyDown[KEY_A])
        cameraNode.Translate(Vector3::LEFT * MOVE_SPEED * timeStep);
    if (input.keyDown[KEY_D])
        cameraNode.Translate(Vector3::RIGHT * MOVE_SPEED * timeStep);

    // Set destination or spawn a jack with left mouse button
    if (input.mouseButtonPress[MOUSEB_LEFT])
        SetPathPoint(input.qualifierDown[QUAL_SHIFT]);
    // Add new obstacle or remove existing obstacle/agent with middle mouse button
    else if (input.mouseButtonPress[MOUSEB_MIDDLE] || input.keyPress[KEY_O])
        AddOrRemoveObject();

    // Check for loading/saving the scene from/to the file Data/Scenes/CrowdNavigation.xml relative to the executable directory
    if (input.keyPress[KEY_F5])
    {
        File saveFile(fileSystem.programDir + "Data/Scenes/CrowdNavigation.xml", FILE_WRITE);
        scene_.SaveXML(saveFile);
    }
    else if (input.keyPress[KEY_F7])
    {
        File loadFile(fileSystem.programDir + "Data/Scenes/CrowdNavigation.xml", FILE_READ);
        scene_.LoadXML(loadFile);
    }

    // Toggle debug geometry with space
    else if (input.keyPress[KEY_SPACE])
        drawDebug = !drawDebug;

    // Toggle instruction text with F12
    else if (input.keyPress[KEY_F12])
    {
        UIElement@ instruction = ui.root.GetChild(INSTRUCTION);
        instruction.visible = !instruction.visible;
    }
}

void ToggleStreaming(bool enabled)
{
    DynamicNavigationMesh@ navMesh = scene_.GetComponent("DynamicNavigationMesh");
    if (enabled)
    {
        int maxTiles = (2 * STREAMING_DISTANCE + 1) * (2 * STREAMING_DISTANCE + 1);
        BoundingBox boundingBox = navMesh.boundingBox;
        SaveNavigationData();
        navMesh.Allocate(boundingBox, maxTiles);
    }
    else
        navMesh.Build();
}

void UpdateStreaming()
{
    DynamicNavigationMesh@ navMesh = scene_.GetComponent("DynamicNavigationMesh");

    // Center the navigation mesh at the crowd of jacks
    Vector3 averageJackPosition;
    Node@ jackGroup = scene_.GetChild("Jacks");
    if (jackGroup !is null)
    {
        for (uint i = 0; i < jackGroup.numChildren; ++i)
            averageJackPosition += jackGroup.children[i].worldPosition;
        averageJackPosition /= jackGroup.numChildren;
    }

    // Compute currently loaded area
    IntVector2 jackTile = navMesh.GetTileIndex(averageJackPosition);
    IntVector2 beginTile = VectorMax(IntVector2(0, 0), jackTile - IntVector2(1, 1) * STREAMING_DISTANCE);
    IntVector2 endTile = VectorMin(jackTile + IntVector2(1, 1) * STREAMING_DISTANCE, navMesh.numTiles - IntVector2(1, 1));

    // Remove tiles
    for (uint i = 0; i < addedTiles.length;)
    {
        IntVector2 tileIdx = addedTiles[i];
        if (beginTile.x <= tileIdx.x && tileIdx.x <= endTile.x && beginTile.y <= tileIdx.y && tileIdx.y <= endTile.y)
            ++i;
        else
        {
            addedTiles.Erase(i);
            navMesh.RemoveTile(tileIdx);
        }
    }

    // Add tiles
    for (int z = beginTile.y; z <= endTile.y; ++z)
        for (int x = beginTile.x; x <= endTile.x; ++x)
        {
            const IntVector2 tileIdx(x, z);
            int tileDataIdx = navigationTilesIdx.Find(tileIdx);
            if (!navMesh.HasTile(tileIdx) && tileDataIdx != -1)
            {
                addedTiles.Push(tileIdx);
                navMesh.AddTile(navigationTilesData[tileDataIdx]);
            }
        }
}

void SaveNavigationData()
{
    DynamicNavigationMesh@ navMesh = scene_.GetComponent("DynamicNavigationMesh");
    navigationTilesData.Clear();
    navigationTilesIdx.Clear();
    addedTiles.Clear();
    IntVector2 numTiles = navMesh.numTiles;
    for (int z = 0; z < numTiles.y; ++z)
        for (int x = 0; x < numTiles.x; ++x)
        {
            IntVector2 idx(x, z);
            navigationTilesData.Push(navMesh.GetTileData(idx));
            navigationTilesIdx.Push(idx);
        }
}

void HandleUpdate(StringHash eventType, VariantMap& eventData)
{
    // Take the frame time step, which is stored as a float
    float timeStep = eventData["TimeStep"].GetFloat();

    // Move the camera, scale movement with time step
    MoveCamera(timeStep);

    // Update streaming
    if (input.keyPress[KEY_TAB])
    {
        useStreaming = !useStreaming;
        ToggleStreaming(useStreaming);
    }
    if (useStreaming)
        UpdateStreaming();
}

void HandlePostRenderUpdate(StringHash eventType, VariantMap& eventData)
{
    if (drawDebug)
    {
        // Visualize navigation mesh, obstacles and off-mesh connections
        cast<DynamicNavigationMesh>(scene_.GetComponent("DynamicNavigationMesh")).DrawDebugGeometry(true);
        // Visualize agents' path and position to reach
        cast<CrowdManager>(scene_.GetComponent("CrowdManager")).DrawDebugGeometry(true);
    }
}

void HandleCrowdAgentFailure(StringHash eventType, VariantMap& eventData)
{
    Node@ node = eventData["Node"].GetPtr();
    int state = eventData["CrowdAgentState"].GetInt();

    // If the agent's state is invalid, likely from spawning on the side of a box, find a point in a larger area
    if (state == CA_STATE_INVALID)
    {
        // Get a point on the navmesh using more generous extents
        Vector3 newPos = cast<DynamicNavigationMesh>(scene_.GetComponent("DynamicNavigationMesh")).FindNearestPoint(node.position, Vector3(5.0f,5.0f,5.0f));
        // Set the new node position, CrowdAgent component will automatically reset the state of the agent
        node.position = newPos;
    }
}

void HandleCrowdAgentFormation(StringHash eventType, VariantMap& eventData)
{
    uint index = eventData["Index"].GetUInt();
    uint size = eventData["Size"].GetUInt();
    Vector3 position = eventData["Position"].GetVector3();

    // The first agent will always move to the exact position, all other agents will select a random point nearby
    if (index > 0)
    {
        CrowdManager@ crowdManager =GetEventSender();
        CrowdAgent@ agent = eventData["CrowdAgent"].GetPtr();
        eventData["Position"] = crowdManager.GetRandomPointInCircle(position, agent.radius, agent.queryFilterType);
    }
}

void HandleCrowdAgentReposition(StringHash eventType, VariantMap& eventData)
{
    const String WALKING_ANI = "Models/Jack_Walk.ani";

    Node@ node = eventData["Node"].GetPtr();
    CrowdAgent@ agent = eventData["CrowdAgent"].GetPtr();
    Vector3 velocity = eventData["Velocity"].GetVector3();
    float timeStep = eventData["TimeStep"].GetFloat();

    // Only Jack agent has animation controller
    AnimationController@ animCtrl = node.GetComponent("AnimationController");
    if (animCtrl !is null)
    {
        float speed = velocity.length;
        if (animCtrl.IsPlaying(WALKING_ANI))
        {
            float speedRatio = speed / agent.maxSpeed;
            // Face the direction of its velocity but moderate the turning speed based on the speed ratio and timeStep
            node.rotation = node.rotation.Slerp(Quaternion(Vector3::FORWARD, velocity), 10.f * timeStep * speedRatio);
            // Throttle the animation speed based on agent speed ratio (ratio = 1 is full throttle)
            animCtrl.SetSpeed(WALKING_ANI, speedRatio * 1.5f);
        }
        else
            animCtrl.Play(WALKING_ANI, 0, true, 0.1f);

        // If speed is too low then stop the animation
        if (speed < agent.radius)
            animCtrl.Stop(WALKING_ANI, 0.5f);
    }
}

// Create XML patch instructions for screen joystick layout specific to this sample app
String patchInstructions =
        "<patch>" +
        "    <add sel=\"/element\">" +
        "        <element type=\"Button\">" +
        "            <attribute name=\"Name\" value=\"Button3\" />" +
        "            <attribute name=\"Position\" value=\"-120 -120\" />" +
        "            <attribute name=\"Size\" value=\"96 96\" />" +
        "            <attribute name=\"Horiz Alignment\" value=\"Right\" />" +
        "            <attribute name=\"Vert Alignment\" value=\"Bottom\" />" +
        "            <attribute name=\"Texture\" value=\"Texture2D;Textures/TouchInput.png\" />" +
        "            <attribute name=\"Image Rect\" value=\"96 0 192 96\" />" +
        "            <attribute name=\"Hover Image Offset\" value=\"0 0\" />" +
        "            <attribute name=\"Pressed Image Offset\" value=\"0 0\" />" +
        "            <element type=\"Text\">" +
        "                <attribute name=\"Name\" value=\"Label\" />" +
        "                <attribute name=\"Horiz Alignment\" value=\"Center\" />" +
        "                <attribute name=\"Vert Alignment\" value=\"Center\" />" +
        "                <attribute name=\"Color\" value=\"0 0 0 1\" />" +
        "                <attribute name=\"Text\" value=\"Spawn\" />" +
        "            </element>" +
        "            <element type=\"Text\">" +
        "                <attribute name=\"Name\" value=\"KeyBinding\" />" +
        "                <attribute name=\"Text\" value=\"LSHIFT\" />" +
        "            </element>" +
        "            <element type=\"Text\">" +
        "                <attribute name=\"Name\" value=\"MouseButtonBinding\" />" +
        "                <attribute name=\"Text\" value=\"LEFT\" />" +
        "            </element>" +
        "        </element>" +
        "        <element type=\"Button\">" +
        "            <attribute name=\"Name\" value=\"Button4\" />" +
        "            <attribute name=\"Position\" value=\"-120 -12\" />" +
        "            <attribute name=\"Size\" value=\"96 96\" />" +
        "            <attribute name=\"Horiz Alignment\" value=\"Right\" />" +
        "            <attribute name=\"Vert Alignment\" value=\"Bottom\" />" +
        "            <attribute name=\"Texture\" value=\"Texture2D;Textures/TouchInput.png\" />" +
        "            <attribute name=\"Image Rect\" value=\"96 0 192 96\" />" +
        "            <attribute name=\"Hover Image Offset\" value=\"0 0\" />" +
        "            <attribute name=\"Pressed Image Offset\" value=\"0 0\" />" +
        "            <element type=\"Text\">" +
        "                <attribute name=\"Name\" value=\"Label\" />" +
        "                <attribute name=\"Horiz Alignment\" value=\"Center\" />" +
        "                <attribute name=\"Vert Alignment\" value=\"Center\" />" +
        "                <attribute name=\"Color\" value=\"0 0 0 1\" />" +
        "                <attribute name=\"Text\" value=\"Obstacles\" />" +
        "            </element>" +
        "            <element type=\"Text\">" +
        "                <attribute name=\"Name\" value=\"MouseButtonBinding\" />" +
        "                <attribute name=\"Text\" value=\"MIDDLE\" />" +
        "            </element>" +
        "        </element>" +
        "    </add>" +
        "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/attribute[@name='Is Visible']\" />" +
        "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Set</replace>" +
        "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button0']]\">" +
        "        <element type=\"Text\">" +
        "            <attribute name=\"Name\" value=\"MouseButtonBinding\" />" +
        "            <attribute name=\"Text\" value=\"LEFT\" />" +
        "        </element>" +
        "    </add>" +
        "    <remove sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/attribute[@name='Is Visible']\" />" +
        "    <replace sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]/element[./attribute[@name='Name' and @value='Label']]/attribute[@name='Text']/@value\">Debug</replace>" +
        "    <add sel=\"/element/element[./attribute[@name='Name' and @value='Button1']]\">" +
        "        <element type=\"Text\">" +
        "            <attribute name=\"Name\" value=\"KeyBinding\" />" +
        "            <attribute name=\"Text\" value=\"SPACE\" />" +
        "        </element>" +
        "    </add>" +
        "</patch>";