Godot3.txt

1. Introducing the Godot Engine
1.1. add _sc_ folder near exe, lead to Self-Contained Mode, all config file portable
1.2. console window is not included in release build
1.3. Editor > Editor Layout, to edit and save/load layout
1.4. Node dock to operate SIGNALs and GROUPs
1.5. Import dock to config asset import setting
1.6. Visual Scripting like Blueprints
1.7. Project Settings page, top tabs and left items
1.8. No multiple script attachment in one Node
2. Scene System
2.1. Node is fundamental element
2.2. game loop
2.2.1. idle game loop, every frame is drawn as fast as possible
2.2.2. fixed game loop, synchronized with the physics loop
2.3. Scene is a nodes in a tree structure
2.3.1. nodes are processed in tree order, root receive process callback before children
2.3.2. nodes are drawn in tree order. parents drawn before children
2.3.3. nodes inherit the transform of their parents
2.4. Resources
2.4.1. Nodes represents behaviors, Resources represent data
2.4.2. Resources can be created via New Resource button, but rarely used this way
2.5. Custom Nodes and Resources
2.5.1. it's possible to create your own node types by creating new editor plugins
2.6. Inspecting and Editing Resources
2.6.1. back and history button, to find previous edited object
2.6.2. some resource types have custom editors. etc. Theme Resource
2.7. Resource Locations and Uniqueness
2.7.1. Resources can either be saved inside the scene file or as its own separate file
2.7.2. Resources are shared by default
2.7.3. Make Unique button to make Resources unique(not shared)
2.8. Combining Scenes
2.8.1. Inheritance is a way to create derived scenes from a same base.
2.8.1.1. Inheriting scenes is the same as instancing them as the root nod for a new scene
2.8.1.2. created by New Inherited Scene button
2.8.2. Instancing Scenes
2.8.2.1. origin changes affect instances, instance changes do not affect origins
2.8.3. Managing Subscenes
2.8.3.1. Open Subscene button (movie icon) to open subscene
2.8.3.2. right-click the Subscene, Editable Children to show subscene structure and edit
2.8.3.3. right-click discard instancing to unlink(Make Local in 3.1 ?)
2.8.3.4. Save Branch as Scene to split a subtree as a new scene
2.8.3.5. Godot checks Cyclic Dependencies, if A -> B -> C, then instance A in C is not allowed
3. 2D Graphics
3.1. Sprites and DrawOrder
3.1.1. Sprites drawn in tree order
3.1.2. RemoteTransform2D node to break the order
3.1.3. Sprite is used as character, prop, HUD. support region render
3.1.4. Texture Region Editor(in the bottom panel) is used when select a Sprite
3.1.5. Animation properties is sometimes more useful for spritesheet animation
3.2. Vector and transform
3.2.1. var m = vector.length() in GDScript
3.2.2. var u = vector.normalized() in GDScript
3.2.3. var rotate_matrix = Transform2D().rotated(deg2rad(90)) in GDScript
3.2.4. var scale_matrix = Transform2D().scaled(Vector2(2, 2))
3.2.5. var translate_matrix = Transform2D().translated
3.2.6. var combined_matrix = translate_matrix * rotate_matrix * scale_matrix
3.2.7. var $my_node.transform *= combined
3.3. Cameras
3.3.1. Camera2D put wherever you want
3.3.2. Camera2D has many properties
3.3.2.1. Offset, changes the camera center
3.3.2.2. Anchor Mode, center or fixed top left
3.3.2.3. Rotating, is useful
3.3.2.4. Current, sets the active camera, there can be only one current camera per viewport
3.3.2.5. Zoom, is useful
3.3.2.6. Limits, clip plane
3.3.2.7. Drag Margins, check the parent position to decide stay or follow the parent
3.3.2.8. Smoothing, if enabled, camera perform smooth transition
3.3.3. Cameras is useful when making split-screen games, one camera for one Viewport
3.4. TileMaps
3.4.1. Godot has TileMap node specifically for this purpose
3.4.2. Make a tileset
3.4.2.1. create a scene, edit the scene with some Sprite nodes
3.4.2.2. if need physics, use StaticBody2D and CollisionShape2D
3.4.2.3. Scene > Convert To > TileSet to generate tileset resource
3.4.2.4. Edit menu, Use Snap and Show Grid options is useful
3.4.3. Use TileMaps
3.4.3.1. Selete TileMap node and use the brush to edit
3.4.3.2. TileMap has many properties
3.4.3.2.1. Tile position, the first item shows the current position of the mouse in tile coordinate
3.4.3.2.2. TileMap, some functions to edit TileMap
3.4.3.2.3. Bucket, filling enclosed area
3.4.3.2.4. Pick Tile, like color picker
3.4.3.2.5. Select, select portion
3.4.3.2.6. Duplicate selection, copy
3.4.3.2.7. Erase Selection, delete
3.4.3.2.8. Transpose, row colums exchange
3.4.3.2.9. Mirror X, mirrors the tile in the horizontal axis.
3.4.3.2.10. Mirror Y, Mirrors the tile in the vertical axis.
3.4.3.2.11. Rotate Buttons, 0, 90, 180, 270 rotations
3.4.3.3. Tile Map Editor is third party tile map editor in Asset Library
3.4.3.4. Other Projections
3.4.3.4.1. Isometric
3.4.3.4.2. Use Custom Transform
3.5. ParallaxBackground
3.5.1. ParallaxBackground node, with ParallaxLayer nodes
3.5.1.1. ParallaxBackground offset, base offset, base scale limit begin/end, Ignore camera zoom is useful
3.5.1.2. ParallaxLayer Scale, Offset Mirroring is useful
3.5.1.3. General construct : one parallex background + n parallex layer, all stuff is layer's children
3.5.1.4. control offset to control layer speed relative to camera
4. Scripting
4.1. Node and Script Relationship(skip)
4.2. Introduction to GDScript
4.2.1. Nice capability to quick prototype
4.2.2. Whitespace-sensitive syntax(like Python, Haskell)
4.2.3. special virtual methods need to override start with underscore(_), like _ready, _process
4.2.4. _ready() call at start
4.2.5. _process(delta) call every frame
4.2.6. Input.is_action_pressed("xxxx") is for keyboard is_action_pressed
4.2.7. var name = expression, initialization syntax
4.2.8. _input(event): if event.is_action_pressed("xxxxx")
4.3. Interfacing with Other Nodes
4.3.1. get_node, param is relative path to current node (UNIX style path)(support .. back)
4.3.1.1. use $ instead of get_node
4.3.2. can call other Node's methods
4.4. Signals and Groups
4.4.1. func _on_Button_pressed():print("xxxx") func _ready(): $Button.connect("pressed", self, "_onButton_pressed")
4.4.1.1. or use Node dock to do the same thing
4.4.2. connecting signals to built-in methods, like "queue_free" can be a real timesaver
4.4.3. signal test_signal(some_argument, another_argument) in GDScript to define a custom signal
4.4.3.1. emit_signal("test_signal") to emit signal
4.4.4. Groups (like a tag)
4.4.4.1. object.add_to_group("shootable") in GDScript to add a object to a group by code
4.4.4.2. get_tree().call_group("group_name", "method_name")
5. Game1 space shooter
5.1. AnimatedSprite to animation
5.2. Timer to emit signal with time
5.3. Project Setting, Display > Window, Width/Height to set game window size, Test Width/Test Height to set window size for testing
5.4. Stretch > Mode to set stretch mode, can support 'logic size'
5.5. Texture import preset has '2D pixel', a pixel-art-friendly setting
5.6. Timer has time_out signal, need start manually
5.7. CanvasLayer separates all its child node into a new canvas layer defined by the Layer property in the Inspector
5.8. use preload('res://scenes/shot.tscn') to preload for later instantiation
5.9. use shot_scene.instance() to instantiate a shot
5.10. use Node.add_child(shot_instance) add a child
5.11. use queue_free() to delete self(in the end of current frame)
6. More Scripting
6.1. Notifications
6.1.1. _notification(what) func to response notify
6.1.2. what could be MainLoop.NOTIFICATION_WM_FOCUS_IN and NOTIFICATION_WM_FOCUS_OUT...
6.1.3. object.notification(int what, bool reverse=false) to send notification
6.1.4. tip : left click to open help in editor
6.1.5. NOTIFICATION_PREDELETE is useful, used to handler some destructure operation
6.1.6. get_tree().quit() to quit game
6.2. Singletons and Autoloads
6.2.1. Commonly Used Singletons
6.2.1.1. ResourceLoader: ResourceLoader.load_interactive can be used to load resources async
6.2.1.2. OS: os functions
6.2.1.3. Engine: get_frames_per_second(), get_version_info(), get_target_fps(), get_frames_drawn()
6.2.1.4. ClassDB: ClassDB.instance(class_name), class_get_method_list, class_get_signal_list, get_inheriters_from_class
6.2.1.5. ProjectSettings: get and set Project settings, don't forget to call save method
6.2.1.6. InputMap: add_action and action_add_event
6.2.1.7. Performance: can monitor draw call and soon
6.2.1.8. Input: get input state
6.2.2. Autoload
6.2.2.1. An autoload is a node that gets loaded at startup and stays loaded for the entire runtime of the application/game.
6.2.2.2. An autoload is always located in the scene tree as a child of the root node
6.2.2.3. autoload need to be set up in Project Settings page
6.2.2.4. use $"/root/GameState.xxxxx" to access autoload
6.3. Editor Tools
6.3.1. use "tool" keyword first line
6.3.2. extend EditorScript second line
6.3.3. override _run()
6.3.4. node.set_owner(get_scene()) is useful
6.4. EditorInterface
6.4.1. get_editor_settings, get_editor_viewport, get_open_scenes, open_scene_from_path, save_scene, save_scene_as...
6.4.2. some_object.some_method(a, b) equals some_object.callv("some_method", [a, b])
7. Handling Input
7.1. Input Basics
7.1.1. use _input(event)
7.1.1.1. use get_tree().get_input_as_handled() to prevent other nodes from responding to it again
7.1.1.2. use set_process_input(enable) to manually start or stop getting input callback
7.1.1.3. func _unhandled_input(event) to handle unhandled input(not marked handled in _input)
7.1.1.4. Special input Handling
7.1.1.4.1. Viewport node can check for mouse position inside itself
7.1.1.4.2. CollisionObject and CollisionObject2D, can receive input events through Camera(click on objects)
7.1.1.4.3. Control, _gui_input(event)
7.1.2. use Input singleton
7.1.2.1. Input.is_key_pressed(scancode)
7.1.2.2. Input.is_mouse_button_pressed(button)
7.1.2.3. Input.is_joy_button_pressed(device, button)
7.2. InputEvent class
7.2.1. Subclasses
7.2.1.1. InputEventAction
7.2.1.2. InputEventJoypadButton - for joystick or gamepad
7.2.1.3. InputEventJoypadMotion - for joystick hat movement
7.2.1.4. InputEventScreenDrag - for swiping on a touch screen
7.2.1.5. InputEventScreenTouch - for tapping on a touch screen
7.2.1.6. InputEventWithModifiers Subclasses
7.2.1.6.1. InputEventKey - for keyboard buttons
7.2.1.6.2. InputEventMouse subclasses
7.2.1.6.2.1. InputEventMouseButton - for mouse buttons
7.2.1.6.2.2. InputEventMouseMotion - for mouse movement
7.3. Keyboard and Joystick Input
7.3.1. Keyboard Input
7.3.1.1. if event is InputEventKey: if event.pressed: prints("Key pressed")
7.3.1.2. OS.get_scancode_string(scancode) to get input code string
7.3.1.3. event.echo to check input echo
7.3.2. Joystick Input
7.3.2.1. if event is InputEventJoypadButton:prints("Buttons:", str(event.button_index))
7.3.2.2. JOY_BUTTON_XXX pattern in button_index
7.4. Mouse and Touch Input
7.4.1. if event is InputEventMouseButton && event.pressed:...
7.4.2. if event is InputEventMouseMotion: ...
7.4.3. if event is InputEventScreenTouch && event.pressed:...
7.4.4. if event is InputEventScreenDrag:...
7.5. Input Mapping
7.5.1. Action is a group of input events that achieve the same task
7.5.2. func _input(event): if event.is_action("move_up"):...
7.5.3. func _process(delta): if Input.is_action_pressed("move_up"):...
7.5.4. Project > Project Settings > Input Map to setup input map
7.5.5. InputMap Singleton
7.5.5.1. InputMap.get_actions() the list of action_add_event
7.5.5.2. InputMap.get_action_list(action) get action list
7.5.5.3. Input.parse_input_event(InputEventAction action) ???
7.5.5.4. Devices can not create InputEventAction
8. Physics System
8.1. Bodies and Shapes
8.1.1. Physics Bodies
8.1.1.1. Static : does not move but interacts with other objects
8.1.1.2. Rigid : interacts with physics engine
8.1.1.3. Kinematic : not affected by physics but need move and detect collisions
8.1.1.4. Vehicle : 3DRoad-traveling vehicles only
8.1.2. Collision Shapes
8.1.2.1. Debug > Visible Collision Shapes to make collision shape visible in game
8.1.2.2. multiple collision nodes for one body is allowed
8.1.2.3. One-way collision is useful
8.1.3. Types of Physics Bodies
8.1.3.1. Static Body, RigidBody
8.1.4. Moving a Kinematic Body
8.1.4.1. move_and_slide(movement) method is useful
8.1.4.2. export (float) var speed = 100.0
8.1.4.3. func _physics_process(delta)
8.2. Areas and Presence Detection
8.2.1. Area Monitoring property is useful
8.2.2. get_overrlapping_areas() and get_overlapping_bodies() to check
8.3. Ray Casting
8.3.1. RayCast node is useful
8.3.2. Ray Casting via Scripting
8.3.2.1. get_world_2d().get_direct_space_state()
8.3.2.2. get_world().get_direct_space_state()
8.3.2.3. then use intersect_ray method
8.4. Navigation and Path Finding
8.4.1. Following Predefined Paths
8.4.1.1. Path and PathFollow, Path2D and PathFollow2D is useful
8.4.2. Basic Path Finding
8.4.2.1. Navigation and Navigation2D node is useful
8.4.2.2. generate a NavigationMeshInstance from a MeshInstance
8.4.2.3. Navigation2D get_simple_path is useful
9. User Interface
9.1. Control is a node inherited from CanvasItem, also Node2D
9.1.1. Control sizing is relative to the parent
9.1.2. Control has Minimum size, for labels that's content
9.1.3. CanvasItem has Show Behind Parent option
9.1.4. Use Anchor button on the top of the scene view
9.1.5. Properties for control is similar to UGUI
9.1.6. Hint is for tooltips
9.2. Know your controls
9.2.1. Label : text,align and valign,autowrap,clip_text
9.2.2. RichTextLabel : (BBCode)
9.2.4. LineEdit : single line text area
9.2.5. TextEdit : multi-line text area
9.2.6. Range : min_value/max_value, value, step
9.2.7. ProgressBar
9.2.8. TextureProgress
9.2.9. Slider
9.2.10. SpinBox
9.2.11. BaseButton, disabled, toggle_mode, pressed, shortcut, group, button_up()/button_down(), pressed(), toggled(bool pressed)
9.2.12. Button
9.2.13. TextureButton
9.2.14. CheckBox and CheckButton
9.2.15. OptionButton
9.2.16. ColorPickerButton
9.2.18. PopupPanel
9.2.19. PopupMenu, id_pressed/index_pressed siganl
9.2.20. WindowDialog
9.2.21. AcceptDialog
9.2.22. ConfirmationDialog
9.2.23. FileDialog, mode, access, fileters, show_hidden_files, dir_selected signal, file_selected signal, files_selected signal
9.2.24. ItemList
9.2.25. TextureRect, has strecth mode
9.2.26. ColorRect
9.2.27. NinePatchRect - important
9.2.28. BoxContainer
9.2.29. SplitContainer
9.2.30. MarginContainer
9.2.31. ScrollContainer
9.2.32. TabContainer
9.3. Making an Interface
9.3.1. $AcceptDialog.dialog_text = "You are ..."
9.3.2. $AcceptDialog.popup()
9.4. Theme
9.4.1. use New Resource to create a Theme resource
9.4.2. Theme has a dock view to check appearance
9.4.3. Theme button on the left-top, then add item
9.4.4. StyleBox can also be add through theme button > add item, pick style on type
9.4.4.1. StyleBoxEmpty: draws nothing
9.4.4.2. StyleBoxFlat: draw a single color
9.4.4.3. StyleBoxTexture: draws an image similar to a NinePatchRect
9.5. Custom Control
9.5.1. Can use GDScript to extend to basic control type
10. Animation
10.1. Animation Editor
10.1.1. every animation needs to be assigned to a node called the AnimationPlayer
10.1.1.1. AnimationPlayer can play any animation you give it
10.1.1.2. AnimationPlayer can only play one animatino at a time
10.1.2. Create a New Animatino with New Animation button on the Animation View
10.1.3. Save the Animation is important
10.1.4. Load the Animation with Open Animation button
10.2. Timeline and Keyframes
10.2.1. set the Length property
10.2.2. keyframe position has step, default 0.1
10.2.3. loop button to toggle loop
10.2.4. the key icon right after the property create the keyframe
10.2.5. Time and Value property is important for a keyframe
10.2.6. Easing functions
10.3. Scripting Animations
10.3.1. Use auto play options on AnimationPlayer to Autoplay
10.3.2. $AnimationPlayer.play("run")
10.3.3. $AnimationPlayer.stop(needReset)
10.3.4. $AnimationPlayer.is_playing()
10.3.5. Animation Signals
10.3.5.1. animation_changed(old_name, new_name)
10.3.5.2. animation_finished(anim_name)
10.3.5.3. animation_started(anim_name)
10.3.6. call func track is useful, like animation event
10.4. Blending and Transitioning Animations
10.4.1. AnimationTreePlayer beside AnimationPlayer
10.4.2. it's complex, try to watch some tutorial video
11. Game Flow
11.1. Scene Tree(A subclass of Main Loop)
11.1.1. change_scene(string path)
11.1.2. change_scene_to(PackedScene packed_scene)
11.1.3. get_current_scene()
11.1.4. is_paused()
11.1.5. set_pause(bool paused)
11.1.6. quit()
11.1.7. reload_current_scene()
11.1.8. set_auto_accept_quit(bool enabled)
11.2. Pausing the game
11.2.1. get_tree().get_paused(true)
11.2.2. puase_mode = PAUSE_MODE_PROCESS to avoid pause
11.3. Switching scenes
11.4. Background loading
11.4.1. ResourceLoader.load_interactive(path) returns loader
11.4.2. loader.poll() return err if has error
11.4.3. ResourceInteractiveLoader.get_resource() to get resource
11.4.4. ResourceInteractiveLoader.wait() to wait for resource
11.5. Handling a Quit Request
11.5.1. use get_tree().set_auto_accept_quit(false) to prevent quit by close window
11.5.2. use get_tree().quit() to actually quit
12. File System
12.1. Special Paths
12.1.1. Resrouces res:// (case sensitive)
12.1.2. User user://
12.1.2.1. Windows: %APPDATA%/.godot/app_userdata/project_name
12.1.2.2. Linux and MacOS: ~/.godot/app_userdata/project_name
12.1.2.3. HTML5: The file system is mocked using the LocalStorage API
12.1.2.4. Android, iOS, UWP application data
12.2. Game Configuration
12.2.1. var config = ConfigFile.new()
12.2.2. config.set_value("options", "difficulty", "hard")...
12.2.3. var err = config.save("user://config.ini")
12.2.4. var err = config.load("user://config.ini")
12.2.5. config.get_value("options", "difficulty")
12.3. Dealing with Files
12.3.1. var file = File.new()
12.3.2. var err = file.open("user://xxx", File.WRITE)
12.3.3. file.store_var(player_name)
12.3.4. file.close()
12.3.5. var err = file.open("user://xxx", File.READ)
12.3.6. file.get_var()
12.3.7. the order of store_var and get_var matters
12.3.8. to_json and from_json to convert from dictionary to text
12.3.9. use File.store_string() and File.get_as_text() to handle json
12.4. Directories
12.4.1. dir = Directory.new()
12.4.2. dir.open("res://")
12.4.3. dir.list_dir_begin()
12.4.4. var name = dir.get_next()
12.4.5. dir.current_is_dir()
12.4.6. dir_list_dir_end()
13. 3D Graphics
13.1. Spatial Node
13.1.1. GDScript + ImmediateGeometry  = dynamic MeshInstance
13.2. Importing Meshes and Models
13.2.1. obj file loses texture and animation
13.2.2. a MeshInstance for a imported model
13.2.3. MultiMesh is useful when too many MeshInstance has performance problem
13.2.4. DAE is used to import complex model/scene
13.2.4.1. for Blender, Better Collada Exporter is needed
13.2.4.2. glTF may replace Collada in the near future
13.3. 3D Editor
13.3.1. Setting > 3d > Navigation Scheme is important
13.3.2. View button on the top is useful
13.3.3. camera shotcut is similar to Blender
13.4. Camera
13.4.1. Preview button on the top-left corner is useful
13.4.2. Interpolated Camera is for focus on a target
13.4.3. $Camera.set_current(true/false) is important
14. Project Management
15. Materials and Shaders
15.1. Canvas Item Materials
15.1.1. CanvasItemMaterial is important, mainly Blend mode
15.1.2. Next Pass is to set up a chain
15.2. Spatial Materials
15.2.1. SpatialMateiral is using PBR
15.2.2. Parameters need tweaking
15.3. Shader Basics
15.3.1. Shader Language is like GLSL
15.3.2. first line must be shader type, shader_type spatial/canvas_item/particles
15.3.3. vertex / fragment / light is function names
15.3.4. Uniforms is needed
15.3.5. VERTEX, TIME, ALBEDO, DIFFUSE_LIGHT, ALBEDO, ATTENUATION is key variables for shader
15.3.6. render_mode is optional, cull_disabled, diffuse_toon is useful
16. Lights and Shadows
16.1. Light Sources
16.1.1. Directional Light
16.1.2. Omni Light(point)
16.1.3. Spot Light
16.1.4. Ambient and Sky Light(Environment)
16.1.5. Emissive Materials
16.1.6. GIProbe node is useful
16.2. Shadows
16.2.1. Directional Light Shadow
16.2.2. Omni Light Shadows
16.2.2.1. Dual-Paraboloid Shadow Mapping(DPSM)
16.2.3. Ambient Occlusion
16.2.3.1. Screen Space Ambient Occlusion(SSAO)
16.2.3.2. occlusion texture
16.2.4. Shadow in 2D
16.2.4.1. LightOccluder2D, Light2D, OccluderPolygon2D is useful
17. Game 2: Bloxorz Clone
17.1. GridMap, like TileMap in 3D
17.2. MeshLibrary, like TileSet in 3D
17.3. Position3D node is useful
18. Environments
18.1. World Environment
18.1.1. if no Environment node, Godot use a default one
18.1.1.1. Project Setting > Rendering > Environment to setup default Environment
18.1.2. Environment under Camera node override other Environment when camera is active
18.1.3. Sky
18.1.3.1. ProcedualSky
18.1.3.2. PanoramaSky
18.1.4. Ambient Light
18.1.5. Fog
18.1.6. Glow and Auto-Exposure
18.1.7. Screen Space Effects
18.1.7.1. SSAO
18.1.7.2. Screen Space Reflection
18.1.8. DoF, far and near
18.1.9. Adjustments
18.1.10. Tone Mapping
18.2. Global Illumination
18.2.1. GIProbe node is useful
18.2.2. Bake button on the tool bar is useful
18.3. ReflectionProbe
19. Sound
19.1. Playing Sounds
19.1.1. wav and ogg format is supported
19.1.2. AudioStreamPlayer2D and 3D is for positional audio
19.1.3. Listener to fetch positional audio, Current property is useful
19.2. Audio Buses
19.2.1. Master bus is the kernal
19.2.2. Multibus is supported
20. Particle System(Skip)
21. Viewports and Canvas
22. Networking
23. Game 3: Networked Bomberman Clone
24. Exporting the Project
25. Native Code