-- Physics example. -- This sample demonstrates: -- - Creating both static and moving physics objects to a scene -- - Displaying physics debug geometry -- - Using the Skybox component for setting up an unmoving sky -- - Saving a scene to a file and loading it to restore a previous state require "LuaScripts/Utilities/Sample" function Start() -- Execute the common startup for samples SampleStart() -- Create the scene content CreateScene() -- Create the UI content CreateInstructions() -- Setup the viewport for displaying the scene SetupViewport() -- Hook up to the frame update and render post-update events SubscribeToEvents() end function CreateScene() scene_ = Scene() -- Create octree, use default volume (-1000, -1000, -1000) to (1000, 1000, 1000) -- Create a physics simulation world with default parameters, which will update at 60fps. Like the Octree must -- exist before creating drawable components, the PhysicsWorld must exist before creating physics components. -- Finally, create a DebugRenderer component so that we can draw physics debug geometry scene_:CreateComponent("Octree") scene_:CreateComponent("PhysicsWorld") scene_:CreateComponent("DebugRenderer") -- Create a Zone component for ambient lighting & fog control local zoneNode = scene_:CreateChild("Zone") local zone = zoneNode:CreateComponent("Zone") zone.boundingBox = BoundingBox(-1000.0, 1000.0) zone.ambientColor = Color(0.15, 0.15, 0.15) zone.fogColor = Color(1.0, 1.0, 1.0) zone.fogStart = 300.0 zone.fogEnd = 500.0 -- Create a directional light to the world. Enable cascaded shadows on it local lightNode = scene_:CreateChild("DirectionalLight") lightNode.direction = Vector3(0.6, -1.0, 0.8) local light = lightNode:CreateComponent("Light") light.lightType = LIGHT_DIRECTIONAL light.castShadows = true light.shadowBias = BiasParameters(0.00025, 0.5) -- Set cascade splits at 10, 50 and 200 world units, fade shadows out at 80% of maximum shadow distance light.shadowCascade = CascadeParameters(10.0, 50.0, 200.0, 0.0, 0.8) -- Create skybox. The Skybox component is used like StaticModel, but it will be always located at the camera, giving the -- illusion of the box planes being far away. Use just the ordinary Box model and a suitable material, whose shader will -- generate the necessary 3D texture coordinates for cube mapping local skyNode = scene_:CreateChild("Sky") skyNode:SetScale(500.0) -- The scale actually does not matter local skybox = skyNode:CreateComponent("Skybox") skybox.model = cache:GetResource("Model", "Models/Box.mdl") skybox.material = cache:GetResource("Material", "Materials/Skybox.xml") -- Create a floor object, 1000 x 1000 world units. Adjust position so that the ground is at zero Y local floorNode = scene_:CreateChild("Floor") floorNode.position = Vector3(0.0, -0.5, 0.0) floorNode.scale = Vector3(1000.0, 1.0, 1000.0) local floorObject = floorNode:CreateComponent("StaticModel") floorObject.model = cache:GetResource("Model", "Models/Box.mdl") floorObject.material = cache:GetResource("Material", "Materials/StoneTiled.xml") -- Make the floor physical by adding RigidBody and CollisionShape components. The RigidBody's default -- parameters make the object static (zero mass.) Note that a CollisionShape by itself will not participate -- in the physics simulation local body = floorNode:CreateComponent("RigidBody") local shape = floorNode:CreateComponent("CollisionShape") -- Set a box shape of size 1 x 1 x 1 for collision. The shape will be scaled with the scene node scale, so the -- rendering and physics representation sizes should match (the box model is also 1 x 1 x 1.) shape:SetBox(Vector3(1.0, 1.0, 1.0)) -- Create a pyramid of movable physics objects for y = 0, 7 do for x = -y, y do local boxNode = scene_:CreateChild("Box") boxNode.position = Vector3(x, -y + 8.0, 0.0) local boxObject = boxNode:CreateComponent("StaticModel") boxObject.model = cache:GetResource("Model", "Models/Box.mdl") boxObject.material = cache:GetResource("Material", "Materials/StoneEnvMapSmall.xml") boxObject.castShadows = true -- Create RigidBody and CollisionShape components like above. Give the RigidBody mass to make it movable -- and also adjust friction. The actual mass is not important only the mass ratios between colliding -- objects are significant local body = boxNode:CreateComponent("RigidBody") body.mass = 1.0 body.friction = 0.75 local shape = boxNode:CreateComponent("CollisionShape") shape:SetBox(Vector3(1.0, 1.0, 1.0)) end end -- Create the camera. Set far clip 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() local camera = cameraNode:CreateComponent("Camera") camera.farClip = 500.0 -- Set an initial position for the camera scene node above the floor cameraNode.position = Vector3(0.0, 5.0, -20.0) end function CreateInstructions() -- Construct new Text object, set string to display and font to use local instructionText = ui.root:CreateChild("Text") instructionText:SetText("Use WASD keys and mouse to move\n".. "LMB to spawn physics objects\n".. "F5 to save scene, F7 to load\n".. "Space to toggle physics debug geometry") 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 SetupViewport() -- Set up a viewport to the Renderer subsystem so that the 3D scene can be seen local viewport = Viewport:new(scene_, cameraNode:GetComponent("Camera")) renderer:SetViewport(0, viewport) end function 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") end function MoveCamera(timeStep) -- Do not move if the UI has a focused element (the console) if ui.focusElement ~= nil then return end -- Movement speed as world units per second local MOVE_SPEED = 20.0 -- Mouse sensitivity as degrees per pixel local MOUSE_SENSITIVITY = 0.1 -- Use this frame's mouse motion to adjust camera node yaw and pitch. Clamp the pitch between -90 and 90 degrees local mouseMove = input.mouseMove yaw = yaw + MOUSE_SENSITIVITY * mouseMove.x pitch = pitch + MOUSE_SENSITIVITY * mouseMove.y pitch = Clamp(pitch, -90.0, 90.0) -- Construct new orientation for the camera scene node from yaw and pitch. Roll is fixed to zero cameraNode.rotation = Quaternion(pitch, yaw, 0.0) -- Read WASD keys and move the camera scene node to the corresponding direction if they are pressed if input:GetKeyDown(KEY_W) then cameraNode:Translate(Vector3(0.0, 0.0, 1.0) * MOVE_SPEED * timeStep) end if input:GetKeyDown(KEY_S) then cameraNode:Translate(Vector3(0.0, 0.0, -1.0) * MOVE_SPEED * timeStep) end if input:GetKeyDown(KEY_A) then cameraNode:Translate(Vector3(-1.0, 0.0, 0.0) * MOVE_SPEED * timeStep) end if input:GetKeyDown(KEY_D) then cameraNode:Translate(Vector3(1.0, 0.0, 0.0) * MOVE_SPEED * timeStep) end -- "Shoot" a physics object with left mousebutton if input:GetMouseButtonPress(MOUSEB_LEFT) then SpawnObject() end -- 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 scene_:SaveXML(fileSystem:GetProgramDir().."Data/Scenes/Physics.xml") end if input:GetKeyPress(KEY_F7) then scene_:LoadXML(fileSystem:GetProgramDir().."Data/Scenes/Physics.xml") end -- Toggle debug geometry with space if input:GetKeyPress(KEY_SPACE) then drawDebug = not drawDebug end end function SpawnObject() -- Create a smaller box at camera position local boxNode = scene_:CreateChild("SmallBox") boxNode.position = cameraNode.position boxNode.rotation = cameraNode.rotation boxNode:SetScale(0.25) local boxObject = boxNode:CreateComponent("StaticModel") boxObject.model = cache:GetResource("Model", "Models/Box.mdl") boxObject.material = cache:GetResource("Material", "Materials/StoneEnvMapSmall.xml") boxObject.castShadows = true -- Create physics components, use a smaller mass also local body = boxNode:CreateComponent("RigidBody") body.mass = 0.25 body.friction = 0.75 local shape = boxNode:CreateComponent("CollisionShape") shape:SetBox(Vector3(1.0, 1.0, 1.0)) local OBJECT_VELOCITY = 10.0 -- Set initial velocity for the RigidBody based on camera forward vector. Add also a slight up component -- to overcome gravity better body.linearVelocity = cameraNode.rotation * Vector3(0.0, 0.25, 1.0) * OBJECT_VELOCITY end function HandleUpdate(eventType, eventData) -- Take the frame time step, which is stored as a float local timeStep = eventData:GetFloat("TimeStep") -- Move the camera, scale movement with time step MoveCamera(timeStep) end function HandlePostRenderUpdate(eventType, eventData) -- If draw debug mode is enabled, draw physics debug geometry. Use depth test to make the result easier to interpret -- Note the convenience accessor to the physics world component if drawDebug then scene_:GetComponent("PhysicsWorld"):DrawDebugGeometry(true) end end -- Create XML patch instructions for screen joystick layout specific to this sample app function GetScreenJoystickPatchString() return "" .. " " .. " Spawn" .. " " .. " " .. " " .. " " .. " " .. " " .. " " .. " Debug" .. " " .. " " .. " " .. " " .. " " .. " " .. "" end