Add VehicleDemo sample in Lua, using update function in script object.

Bin/Data/LuaScripts/01_HelloWorld.lua

@@ -26,7 +26,7 @@ function CreateText()
     local helloText = Text:new(context)
 
     -- Set String to display
-    helloText:SetText("Hello World from Urho3D!");
+    helloText.text = "Hello World from Urho3D!"
 
     -- Set font and text color
     local cache = GetCache()

Bin/Data/LuaScripts/05_AnimatingScene.lua

@@ -164,17 +164,13 @@ end
 Rotator = ScriptObject()
 
 function Rotator:Start()
-    --self.rotationSpeed = Vector3(0.0, 0.0, 0.0)
     self.rotationSpeed = {0.0, 0.0, 0.0}
-    self:SubscribeToEvent("Update", "Rotator.Update")
 end
 
 function Rotator:Stop()
 end
 
--- Update is called during the variable timestep scene update
-function Rotator.Update(self, eventType, eventData)
-    local timeStep = eventData:GetFloat("TimeStep")
+function Rotator:Update(timeStep)
     local x = self.rotationSpeed[1] * timeStep
     local y = self.rotationSpeed[2] * timeStep
     local z = self.rotationSpeed[3] * timeStep

Bin/Data/LuaScripts/06_SkeletalAnimation.lua

@@ -205,8 +205,6 @@ function Mover:Start()
     self.moveSpeed = 0.0
     self.rotationSpeed = 0.0
     self.bounds = BoundingBox()
-    
-    self:SubscribeToEvent("Update", "Mover:Update")
 end
 
 function Mover:SetParameters(moveSpeed, rotationSpeed, bounds)
@@ -215,9 +213,7 @@ function Mover:SetParameters(moveSpeed, rotationSpeed, bounds)
     self.bounds = bounds
 end
 
-function Mover:Update(eventType, eventData)
-    local timeStep = eventData:GetFloat("TimeStep")
-    
+function Mover:Update(timeStep)
     local node = self:GetNode()
     node:TranslateRelative(Vector3(0.0, 0.0, 1.0) * self.moveSpeed * timeStep)
     

Bin/Data/LuaScripts/12_PhysicsStressTest.lua

@@ -210,17 +210,10 @@ function MoveCamera(timeStep)
     -- Check for loading/saving the scene. Save the scene to the file Data/Scenes/Physics.xml relative to the executable
     -- directory
     if input:GetKeyPress(KEY_F5) then
-        print("Filepath " .. fileSystem:GetProgramDir().."Data/Scenes/PhysicsStressTest.xml")
-        local saveFile = File(context, fileSystem:GetProgramDir().."Data/Scenes/PhysicsStressTest.xml", FILE_WRITE)
-        scene_:SaveXML(saveFile)
-        -- Make sure the file gets closed
-        saveFile:Close()
+        scene_:SaveXML(fileSystem:GetProgramDir().."Data/Scenes/PhysicsStressTest.xml")
     end
     if input:GetKeyPress(KEY_F7) then
-        local loadFile = File(context, fileSystem:GetProgramDir().."Data/Scenes/PhysicsStressTest.xml", FILE_READ)
-        scene_:LoadXML(loadFile)
-        -- Make sure the file gets closed
-        loadFile:Close()
+        scene_:LoadXML(fileSystem:GetProgramDir().."Data/Scenes/PhysicsStressTest.xml")
     end
 
     -- Toggle debug geometry with space

Bin/Data/LuaScripts/19_VehicleDemo.lua

@@ -0,0 +1,379 @@
+-- Vehicle example.
+-- This sample demonstrates:
+--     - Creating a heightmap terrain with collision;
+--     - Constructing a physical vehicle with rigid bodies for the hull and the wheels, joined with constraints;
+
+require "LuaScripts/Utilities/Sample"
+
+local CTRL_FORWARD = 1
+local CTRL_BACK = 2
+local CTRL_LEFT = 4
+local CTRL_RIGHT = 8
+
+local CAMERA_DISTANCE = 10.0
+local YAW_SENSITIVITY = 0.1
+local ENGINE_POWER = 10.0
+local DOWN_FORCE = 10.0
+local MAX_WHEEL_ANGLE = 22.5
+
+local scene_ = nil
+local cameraNode = nil
+local vehicleNode = nil
+
+local context = GetContext()
+
+local cache = GetCache()
+local fileSystem = GetFileSystem()
+local input = GetInput()
+local renderer = GetRenderer()
+local ui = GetUI()
+
+function Start()
+
+    -- Execute the common startup for samples
+    SampleStart()
+    
+    -- Create static scene content
+    CreateScene()
+
+    -- Create the controllable vehicle
+    CreateVehicle()
+
+    -- Create the UI content
+    CreateInstructions()
+
+    -- Subscribe to necessary events
+    SubscribeToEvents()
+end
+
+function CreateScene()
+    scene_ = Scene(context)
+
+    -- Create scene subsystem components
+    scene_:CreateComponent("Octree")
+    scene_:CreateComponent("PhysicsWorld")
+
+    -- Create camera and define viewport. Camera does not necessarily have to belong to the scene
+    cameraNode = Node(context)
+    local camera = cameraNode:CreateComponent("Camera")
+    camera.farClip = 500.0
+    
+    renderer:SetViewport(0, Viewport:new(context, scene_, camera))
+    
+    -- Create static scene content. First create a zone for ambient lighting and fog control
+    local zoneNode = scene_:CreateChild("Zone")
+    local zone = zoneNode:CreateComponent("Zone")
+    zone.ambientColor = Color(0.15, 0.15, 0.15)
+    zone.fogColor = Color(0.5, 0.5, 0.7)
+    zone.fogStart = 300.0
+    zone.fogEnd = 500.0
+    zone.boundingBox = BoundingBox(-2000.0, 2000.0)
+
+    -- Create a directional light to the world. Enable cascaded shadows on it
+    local lightNode = scene_:CreateChild("DirectionalLight")
+    lightNode.direction = Vector3(0.3, -0.5, 0.425)
+    local light = lightNode:CreateComponent("Light")
+    light.lightType = LIGHT_DIRECTIONAL
+    light.castShadows = true
+    light.shadowBias = BiasParameters(0.0001, 0.5)
+    light.shadowCascade = CascadeParameters(10.0, 50.0, 200.0, 0.0, 0.8)
+    light.specularIntensity = 0.5
+
+    -- Create heightmap terrain with collision
+    local terrainNode = scene_:CreateChild("Terrain")
+    terrainNode.position = Vector3(0.0, 0.0, 0.0)
+    local terrain = terrainNode:CreateComponent("Terrain")
+    terrain.patchSize = 64
+    terrain.spacing = Vector3(2.0, 0.1, 2.0) -- Spacing between vertices and vertical resolution of the height map
+    terrain.smoothing = true
+    terrain.heightMap = cache:GetResource("Image", "Textures/HeightMap.png")
+    terrain.material = cache:GetResource("Material", "Materials/Terrain.xml")
+    -- The terrain consists of large triangles, which fits well for occlusion rendering, as a hill can occlude all
+    -- terrain patches and other objects behind it
+    terrain.occluder = true
+    
+    local body = terrainNode:CreateComponent("RigidBody")
+    body.collisionLayer = 2 -- Use layer bitmask 2 for static geometry
+    local shape = terrainNode:CreateComponent("CollisionShape")
+    shape:SetTerrain()
+
+    -- Create 1000 mushrooms in the terrain. Always face outward along the terrain normal
+    local NUM_MUSHROOMS = 1000
+    for i = 1, NUM_MUSHROOMS do
+        local objectNode = scene_:CreateChild("Mushroom")
+        local position = Vector3(Random(2000.0) - 1000.0, 0.0, Random(2000.0) - 1000.0)
+        position.y = terrain:GetHeight(position) - 0.1
+        objectNode.position = position
+        -- Create a rotation quaternion from up vector to terrain normal
+        objectNode.rotation = Quaternion(Vector3(0.0, 1.0, 0.0), terrain:GetNormal(position))
+        objectNode:SetScale(3.0)
+        local object = objectNode:CreateComponent("StaticModel")
+        object.model = cache:GetResource("Model", "Models/Mushroom.mdl")
+        object.material = cache:GetResource("Material", "Materials/Mushroom.xml")
+        object.castShadows = true
+        
+        local body = objectNode:CreateComponent("RigidBody")
+        body.collisionLayer = 2
+        local shape = objectNode:CreateComponent("CollisionShape")
+        shape:SetTriangleMesh(object.model, 0)
+    end
+end
+
+function CreateVehicle()
+    vehicleNode = scene_:CreateChild("Vehicle")
+    vehicleNode.position = Vector3(0.0, 5.0, 0.0)
+    
+    -- Create the vehicle logic script object
+    local vehicle = vehicleNode:CreateScriptObject("Vehicle")
+    -- Create the rendering and physics components
+    vehicle:Init()
+end
+
+function CreateInstructions()
+    -- Construct new Text object, set string to display and font to use
+    local instructionText = ui.root:CreateChild("Text")
+    instructionText.text = "Use WASD keys to drive, mouse to rotate camera\n"..
+        "F5 to save scene, F7 to load"
+    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)
+end
+
+function SubscribeToEvents()
+    -- Subscribe to Update event for setting the vehicle controls before physics simulation
+    SubscribeToEvent("Update", "HandleUpdate")
+
+    -- Subscribe to PostUpdate event for updating the camera position after physics simulation
+    SubscribeToEvent("PostUpdate", "HandlePostUpdate")
+end
+
+function HandleUpdate(eventType, eventData)
+    if vehicleNode == nil then
+        return
+    end
+
+    local vehicle = vehicleNode:GetScriptObject()
+    if vehicle == nil then
+        return
+    end
+
+    -- Get movement controls and assign them to the vehicle component. If UI has a focused element, clear controls
+    if ui.focusElement == nil then
+        vehicle.controls:Set(CTRL_FORWARD, input:GetKeyDown(KEY_W))
+        vehicle.controls:Set(CTRL_BACK, input:GetKeyDown(KEY_S))
+        vehicle.controls:Set(CTRL_LEFT, input:GetKeyDown(KEY_A))
+        vehicle.controls:Set(CTRL_RIGHT, input:GetKeyDown(KEY_D))
+
+        -- Add yaw & pitch from the mouse motion. Used only for the camera, does not affect motion
+        vehicle.controls.yaw = vehicle.controls.yaw + input.mouseMoveX * YAW_SENSITIVITY
+        vehicle.controls.pitch = vehicle.controls.pitch + input.mouseMoveY * YAW_SENSITIVITY
+        -- Limit pitch
+        vehicle.controls.pitch = Clamp(vehicle.controls.pitch, 0.0, 80.0)
+
+        -- Check for loading / saving the scene
+        if input:GetKeyPress(KEY_F5) then
+            scene_:SaveXML(fileSystem:GetProgramDir() .. "Data/Scenes/VehicleDemo.xml")
+        end
+        if input:GetKeyPress(KEY_F7) then
+            scene_:LoadXML(fileSystem:GetProgramDir() .. "Data/Scenes/VehicleDemo.xml")
+            -- After loading we have to reacquire the vehicle scene node, as it has been recreated
+            -- Simply find by name as there's only one of them
+            vehicleNode = scene_:GetChild("Vehicle", true)
+            vehicleNode:GetScriptObject():PostInit()
+        end
+    else
+        vehicle.controls:Set(CTRL_FORWARD + CTRL_BACK + CTRL_LEFT + CTRL_RIGHT, false)
+    end
+end
+
+function HandlePostUpdate(eventType, eventData)
+    if vehicleNode == nil then
+        return
+    end
+    
+    local vehicle = vehicleNode:GetScriptObject()
+    if vehicle == nil then
+        return
+    end
+
+    -- Physics update has completed. Position camera behind vehicle
+    local dir = Quaternion(vehicleNode.rotation:YawAngle(), Vector3(0.0, 1.0, 0.0))
+    dir = dir * Quaternion(vehicle.controls.yaw, Vector3(0.0, 1.0, 0.0))
+    dir = dir * Quaternion(vehicle.controls.pitch, Vector3(1.0, 0.0, 0.0))
+    
+    local cameraTargetPos = vehicleNode.position - dir * Vector3(0.0, 0.0, CAMERA_DISTANCE)
+    local cameraStartPos = vehicleNode.position
+    -- Raycast camera against static objects (physics collision mask 2)
+    -- and move it closer to the vehicle if something in between
+    local cameraRay = Ray(cameraStartPos, (cameraTargetPos - cameraStartPos):Normalized())
+    local cameraRayLength = (cameraTargetPos - cameraStartPos):Length();
+    local physicsWorld = scene_:GetComponent("PhysicsWorld")
+    local result = physicsWorld:RaycastSingle(cameraRay, cameraRayLength, 2)
+    if result.body ~= nil then
+        cameraTargetPos = cameraStartPos + cameraRay.direction * (result.distance - 0.5)
+    end
+    cameraNode.position = cameraTargetPos
+    cameraNode.rotation = dir
+end
+
+-- Vehicle script object class
+--
+-- When saving, the node and component handles are automatically converted into nodeID or componentID attributes
+-- and are acquired from the scene when loading. The steering member variable will likewise be saved automatically.
+-- The Controls object can not be automatically saved, so handle it manually in the Load() and Save() methods
+
+Vehicle = ScriptObject()
+
+function Vehicle:Start()
+    -- Current left/right steering amount (-1 to 1.)
+    self.steering = 0.0
+    -- Vehicle controls.
+    self.controls = Controls()
+end
+
+function Vehicle:Load(deserializer)
+    self.controls.yaw = deserializer:ReadFloat()
+    self.controls.pitch = deserializer:ReadFloat()
+end
+
+function Vehicle:Save(serializer)
+    serializer:WriteFloat(self.controls.yaw)
+    serializer:WriteFloat(self.controls.pitch)
+end
+
+function Vehicle:Init()
+    -- This function is called only from the main program when initially creating the vehicle, not on scene load
+    local node = self.node
+    local hullObject = node:CreateComponent("StaticModel")
+    self.hullBody = node:CreateComponent("RigidBody")
+    local hullShape = node:CreateComponent("CollisionShape")
+    
+    node.scale = Vector3(1.5, 1.0, 3.0)
+    hullObject.model = cache:GetResource("Model", "Models/Box.mdl")
+    hullObject.material = cache:GetResource("Material", "Materials/Stone.xml")
+    hullObject.castShadows = true
+    hullShape:SetBox(Vector3(1.0, 1.0, 1.0))
+    
+    self.hullBody.mass = 4.0
+    self.hullBody.linearDamping = 0.2 -- Some air resistance
+    self.hullBody.angularDamping = 0.5
+    self.hullBody.collisionLayer = 1
+    self.frontLeft = self:InitWheel("FrontLeft", Vector3(-0.6, -0.4, 0.3))
+    self.frontRight = self:InitWheel("FrontRight", Vector3(0.6, -0.4, 0.3))
+    self.rearLeft = self:InitWheel("RearLeft", Vector3(-0.6, -0.4, -0.3))
+    self.rearRight = self:InitWheel("RearRight", Vector3(0.6, -0.4, -0.3))
+
+    self:PostInit()
+end
+
+function Vehicle:PostInit()
+    self.frontLeft = scene_:GetChild("FrontLeft")
+    self.frontRight = scene_:GetChild("FrontRight")
+    self.rearLeft = scene_:GetChild("RearLeft")
+    self.rearRight = scene_:GetChild("RearRight")
+    
+    self.frontLeftAxis = self.frontLeft:GetComponent("Constraint")
+    self.frontRightAxis = self.frontRight:GetComponent("Constraint")
+    
+    self.hullBody = self.node:GetComponent("RigidBody")
+    
+    self.frontLeftBody = self.frontLeft:GetComponent("RigidBody")
+    self.frontRightBody = self.frontRight:GetComponent("RigidBody")
+    self.rearLeftBody = self.rearLeft:GetComponent("RigidBody")
+    self.rearRightBody = self.rearRight:GetComponent("RigidBody")
+end
+
+function Vehicle:InitWheel(name, offset)
+    -- Note: do not parent the wheel to the hull scene node. Instead create it on the root level and let the physics
+    -- constraint keep it together
+    local wheelNode = scene_:CreateChild(name)
+    local node = self.node
+    wheelNode.position = node:LocalToWorld(offset)
+    if offset.x >= 0.0 then
+        wheelNode.rotation = node.worldRotation * Quaternion(0.0, 0.0, -90.0)
+    else
+        wheelNode.rotation = node.worldRotation * Quaternion(0.0, 0.0, 90.0)
+    end
+    wheelNode.scale = Vector3(0.8, 0.5, 0.8)
+
+    local wheelObject = wheelNode:CreateComponent("StaticModel")
+    local wheelBody = wheelNode:CreateComponent("RigidBody")
+    local wheelShape = wheelNode:CreateComponent("CollisionShape")
+    local wheelConstraint = wheelNode:CreateComponent("Constraint")
+
+    wheelObject.model = cache:GetResource("Model", "Models/Cylinder.mdl")
+    wheelObject.material = cache:GetResource("Material", "Materials/Stone.xml")
+    wheelObject.castShadows = true
+    wheelShape:SetSphere(1.0)
+    wheelBody.friction = 1
+    wheelBody.mass = 1
+    wheelBody.linearDamping = 0.2 -- Some air resistance
+    wheelBody.angularDamping = 0.75 -- Could also use rolling friction
+    wheelBody.collisionLayer = 1
+    wheelConstraint.constraintType = CONSTRAINT_HINGE
+    wheelConstraint.otherBody = node:GetComponent("RigidBody")
+    wheelConstraint.worldPosition = wheelNode.worldPosition -- Set constraint's both ends at wheel's location
+    wheelConstraint.axis = Vector3(0.0, 1.0, 0.0) -- Wheel rotates around its local Y-axis
+    
+    if offset.x >= 0.0 then -- Wheel's hull axis points either left or right
+        wheelConstraint.otherAxis = Vector3(1.0, 0.0, 0.0)
+    else
+        wheelConstraint.otherAxis = Vector3(-1.0, 0.0, 0.0)
+    end
+    
+    wheelConstraint.lowLimit = Vector2(-180.0, 0.0) -- Let the wheel rotate freely around the axis
+    wheelConstraint.highLimit = Vector2(180.0, 0.0)
+    wheelConstraint.disableCollision = true -- Let the wheel intersect the vehicle hull
+
+    return wheelNode
+end
+
+function Vehicle:FixedUpdate(timeStep)
+    local newSteering = 0.0
+    local accelerator = 0.0
+
+    if self.controls:IsDown(CTRL_LEFT) then
+        newSteering = -1.0
+    end
+    if self.controls:IsDown(CTRL_RIGHT) then
+        newSteering = 1.0
+    end
+    if self.controls:IsDown(CTRL_FORWARD) then
+        accelerator = 1.0
+    end
+    if self.controls:IsDown(CTRL_BACK) then
+        accelerator = -0.5
+    end
+    
+    -- When steering, wake up the wheel rigidbodies so that their orientation is updated
+    if newSteering ~= 0.0 then
+        self.frontLeftBody:Activate()
+        self.frontRightBody:Activate()
+        self.steering = self.steering * 0.95 + newSteering * 0.05
+    else
+        self.steering = self.steering * 0.8 + newSteering * 0.2
+    end
+
+    local steeringRot = Quaternion(0.0, self.steering * MAX_WHEEL_ANGLE, 0.0)
+    self.frontLeftAxis.otherAxis = steeringRot * Vector3(-1.0, 0.0, 0.0)
+    self.frontRightAxis.otherAxis = steeringRot * Vector3(1.0, 0.0, 0.0)
+
+    if accelerator ~= 0.0 then
+        -- Torques are applied in world space, so need to take the vehicle & wheel rotation into account
+        local torqueVec = Vector3(ENGINE_POWER * accelerator, 0.0, 0.0)
+        local node = self.node
+        self.frontLeftBody:ApplyTorque(node.rotation * steeringRot * torqueVec)
+        self.frontRightBody:ApplyTorque(node.rotation * steeringRot * torqueVec)
+        self.rearLeftBody:ApplyTorque(node.rotation * torqueVec)
+        self.rearRightBody:ApplyTorque(node.rotation * torqueVec)
+    end
+
+    -- Apply downforce proportional to velocity
+    local localVelocity = self.hullBody.rotation:Inverse() * self.hullBody.linearVelocity
+    self.hullBody:ApplyForce(self.hullBody.rotation * Vector3(0.0, -1.0, 0.0) * Abs(localVelocity.z) * DOWN_FORCE)
+end

Bin/Data/LuaScripts/TestScene.lua

@@ -349,17 +349,12 @@ function HandleKeyDown(eventType, eventData)
         
         
         if key == KEY_F5  then
-            local xmlFile = File(context, fileSystem:GetProgramDir() + "Data/Scenes/LuaTestScene.xml", FILE_WRITE)
-            testScene:SaveXML(xmlFile)
+            testScene:SaveXML(fileSystem:GetProgramDir() + "Data/Scenes/LuaTestScene.xml")
         end
         
         if key == KEY_F7 then
-            local xmlFile = File(context, fileSystem:GetProgramDir() + "Data/Scenes/LuaTestScene.xml", FILE_READ)
-            if xmlFile:IsOpen() then
-                testScene:LoadXML(xmlFile)
-            end
+            testScene:LoadXML(fileSystem:GetProgramDir() + "Data/Scenes/LuaTestScene.xml")
         end
-        --]]
     end    
 end