Unity3D. Unity3D is a powerful cross-platform 3D engine and a user friendly development environment.

Transcription

1 Unity3D Unity3D is a powerful cross-platform 3D engine and a user friendly development environment. If you didn t like OpenGL, hopefully you ll like this. Remember the Rotating Earth? Look how it s done with Unity3D.

2 Fire up Unity3D Rotating Earth

3 Rotating Earth Create new project ( Rotating Earth ):

4 Rotating Earth From the top menu add Game Object > 3D Object > Sphere

5 Rotating Earth With sphere selected, change its scale to 8, 8, 8 in the Inspector:

6 Rotating Earth Download earth.png and drag it from Finder into Assets folder at the bottom:

7 Rotating Earth Now, drag earth.png from Assets folder onto the sphere and release: Observe that new subfolder Materials has been created with material earth in it:

8 Rotating Earth Hit Play button on top:

9 Rotating Earth Let s change the background. From Hierarchy (upper left corner) select Main Camera. In Inspector (upper right corner), change Clear Flags from Skybox to Solid color and change background to black (0, 0, 0)

10 Rotating Earth Hit Play button on top:

11 Rotating Earth In order to rotate earth about its own axis we need a script. Select Sphere from Hierarchy and in Inspector Add Component > Scripts > New Script (rename to RotateEarth), Language C# Observe that newly created script appears in Assets

12 RotateEarth.cs Double-click on script in Assets and MonoDevelop editor should appear. Script comes with two empty methods: void Start() which is used for variable initialization, and void Update() which is called once per frame.

13 RotateEarth.cs using UnityEngine; using System.Collections; public class RotateEarth : MonoBehaviour { // Use this for initialization void Start () { } } // Update is called once per frame void Update () { transform.rotate(vector3.up, 20 * Time.deltaTime); }

14 RotateEarth.cs Function Rotate() takes two arguments: Vector3.up - Specifies rotation axis (0, 1, 0) Time.deltaTime - The time in seconds it took to complete the last frame (angle argument).

15 RotateEarth.cs If we wanted to rotate Earth about its axis AND about the origin (0, 1, 0) we need another function: public void RotateAround(Vector3 point, Vector3 axis, float angle); which rotates the transform about axis passing through point in world coordinates by angle degrees.

16 RotateEarth.cs using UnityEngine; using System.Collections; public class RotateEarth : MonoBehaviour { // Use this for initialization void Start () { } } // Update is called once per frame void Update () { transform.rotatearound (Vector3.zero, Vector3.up, 14 * Time.deltaTime); transform.rotate(vector3.up, 20 * Time.deltaTime); }

17 RotateEarth.cs If you play it now, there will be no difference, since both vectors coincide. Translate Sphere along the z axis (z = 4) and run.

18 It s alive!

19 Unity Interface Toolbar Hierarchy Scene Project Inspector

20 Scene Navigation Arrow Movement The up and down arrows move the camera forward and backward in the direction it is facing. The left and right arrows pan the view sideways. Hold down the Shift key with an arrow to move faster.

21 Scene Navigation Focusing If you select a GameObject in the hierarchy, then move the mouse over the scene view and press F, the view will move so as to center on the object. This feature is referred to as Frame Selected under the Edit menu.

22 Scene Navigation Move, Orbit and Zoom When the hand tool is selected (shortcut: Q), the following mouse controls are available: Move: Click-drag to drag the camera around.

23 Scene Navigation Orbit: Hold Alt and click-drag to orbit the camera around the current pivot point. This option is not available in 2D mode as the view is orthographic. Zoom: Hold Alt and right click-drag to zoom the Scene View. On Mac you can also hold Control and clickdrag instead.

24 Scene Navigation Flythrough Mode mode lets you navigate the Scene View by flying around in first person view. Click and hold the right mouse button. Use mouse and WASD keys to move left/right forward/backward and QE keys to move up and down. Holding down Shift will make you move faster.

25 Primitive Objects Unity can work with 3D models of any shape that can be created with modelling software. There are also a number of primitive object types that can be created directly within Unity, namely the Cube, Sphere, Capsule, Cylinder, Plane and Quad. Any of the primitives can be added to the scene using the appropriate item on the GameObject > 3D Object menu.

26 Cube This is a simple cube with sides one unit long, textured so that the image is repeated on each of the six faces.

27 Sphere This is a sphere of unit diameter, textured so that the entire image wraps around once with the top and bottom pinched at the poles.

28 Capsule A capsule is a cylinder with hemispherical caps at the ends. The object is one unit in diameter and two units high.

29 Cylinder This is a simple cylinder which is two units high and one unit in diameter.

30 Plane This is a flat square with edges ten units long oriented in the XZ plane of the local coordinate space.

31 Quad The quad primitive resembles the plane but its edges are only one unit long and the surface is oriented in the XY plane.

32 Complex objects There are several different ways to include complex objects into the scene: 1. By importing objects from Unity Asset Store 2. By importing objects designed in some modelling software (Maya, Sketchup etc) 3. By using Probuilder

33 Probuilder Basic

34 Materials We have already used materials in our Rotating Earth project. They play an essential part in defining how our object is displayed.

35 Creating Materials To create a new Material, use Assets > Create > Material from the main menu or the Project View context menu. By default, new materials are assigned the Standard Shader, with all map properties empty.

36 Using Materials Once the Material has been created, you can apply it to an object and tweak all of its properties in the Inspector. To apply it to an object, just drag it from the Project View to any object in the Scene or Hierarchy.

37 Material Properties The properties that a Material s inspector displays are determined by the Shader that the Material uses. A shader is a specialised kind of graphical program that determines how texture and lighting information are combined to generate the pixels of the rendered object onscreen.

38 Material Properties You can select which Shader you want any particular Material to use. Simply expand the Shader drop-down in the Inspector, and choose your new Shader. The Shader you choose will dictate the available properties to change.

39 Material Properties The properties can be colors, sliders, textures, numbers, or vectors. If you have applied the Material to an active object in the Scene, you will see your property changes applied to the object in real-time.

40 Material Properties There are two ways to apply a Texture to a property. 1. Drag it from the Project View on top of the Texture square 2. Click the Select button, and choose the texture from the drop-down list that appears

41 Built-in Shaders FX Lighting and glass effects GUI and UI Mobile Nature For user interface graphics Simplified high-performance shader for mobile devices For trees and terrain Particles Particle system effects

42 Built-in Shaders Skybox Sprites For rendering background environments behind all geometry For use with the 2D sprite system Toon Unlit Legacy Cartoon-style rendering For rendering that entirely bypasses all light & shadowing The large collection of older shaders which were superseded by the Standard Shader

43 Lighting In order to calculate the shading of a 3D object, Unity needs to know the intensity, direction and color of the light. Bright shading Light source These properties are provided by Light objects in the scene. Dark shading

44 Types of light Point Light is located at a point in space and sends light out in all directions equally.

45 Point Light Useful for simulating lamps and other local sources of light in a scene.

46 Types of Light Spot Light has a specified location and range over which the light falls off.

47 Spot Light Spot lights are generally used for artificial light sources such as flashlights

48 Types of Light Directional Light represents large, distant source that comes from a position outside the range of the game world. Direction only

49 Directional Light Can be used to simulate the sun or moon

50 Types of Light Area Light is defined by a rectangle in space. Light is emitted in all directions, but only from one side of the rectangle. The light falls off over a specified range. range Can be used to create a realistic street light for example.

51 Using lights GameObject > Light > Type

52 Shadows Illuminated area Shadow where light doesn t reach the surface

53 Shadows Shadows for an individual light are set with the Shadow Type property. Objects have properties Cast and Receive Shadows.

54 Cookies Shadows can also be created by placing a shaped mask in between the light source and the action. The mask is known as a cucoloris or cookie A cookie is just an ordinary texture but only the alpha/transparency channel is relevant

55 Cookies Simple cookie for a window light Imported into assets Inspector settings Texture Type: Cookie

56 Cookies In order to apply a cookie to a light, select light and drag it to the Light s Cookie property in the inspector to apply it.

57 Cookies

58 Create new Project Roll a Ball

59 Scene Save scene (File, Save Scene as or S)

60 Add Object to Scene Add Plane to the scene (Game Object, 3D, Plane)

61 Position In Hierarchy select Plane and in Inspector, change its name to Ground If the Ground is not positioned in the center of the coordinate system (0, 0, 0), reset it using gear

62 Scaling Plane can be scaled either by selecting the scale icon and stretching the plane in X or Z direction Or directly setting transformation scale coordinates in the Inspector (2, 1, 2)

63 More Objects Add a player (Sphere from object menu) and rename it to Player. Observe that Sphere is buried in the plane.

64 Change Position Center of the sphere is in the centre of the coordinate system. In Inspector, set sphere s Y position coordinate to 0.5

65 Materials and Colors Create new Folder under Project/Create. Rename it to Materials.

66 Materials and Colors With Materials folder selected, create Material. Rename New Material to Background.

67 Materials and Colors With Material selected, in Inspector, next to Albedo is the color selector. Set it to some color (e.g. 0, 32, 64)

68 Apply Material to Object To apply material to an object, simply select material and drag into object (Ground in our case).

69 Change Light Direction Select Directional Light and using Inspector, change Rotation Y coordinate to 60

70 Rigid Bodies How to move Player around the Ground? This Requires Physics. Select Player (Sphere) and in Inspector, Add Component, Physics, Rigid body

71 Rigidbody Rigidbodies enable GameObjects to act under the control of physics. The Rigidbody can receive forces and torque to make objects move in a realistic way.

72 Rigidbody properties Mass The mass of the object (in kilograms by default). Drag How much air resistance affects the object when moving from forces. 0 means no air resistance, and infinity makes the object stop moving immediately.

73 Rigidbody properties Angular Drag How much air resistance affects the object when rotating from torque. 0 means no air resistance. Use Gravity If enabled, the object is affected by gravity.

74 Rigidbody properties Is Kinematic If enabled, the object will not be driven by the physics engine, and can only be manipulated by its Transform. Interpolate Try one of the options only if you are seeing jerkiness in your Rigidbody s movement.

75 Rigidbody properties Collision Detection Used to prevent fast moving objects from passing through other objects without detecting collisions. Constraints Restrictions on the Rigidbody s motion.

76 Movement Not much movement so far. In order to move Player around the Ground, we have to take and process inputs (Keyboard, Accelerometer etc). And for that we need to write code. First of all create another folder called Scripts.

77 Movement To create controller for our Player, select Player, Add Component, New Script. Name: PlayerController, Type: C-Sharp You might have to move newly created script into Scripts folder

78 C# Script If you select PlayerController script, you can see in the Inspector that some code has already been generated for us. However, code is not editable in Inspector. Doubleclick PlayerController and start MonoDevelop (editor)

79 C# Script using UnityEngine; using System.Collections; public class PlayerController : MonoBehaviour { // Use this for initialization void Start () { } // Update is called once per frame void Update () { } }

80 C# Script Start () method is called once in order to initialize variables. Which variables do we need? Speed and reference to our player: public float speed; private Rigidbody rb;

81 C# Script Start () method initializes our Player : void Start () { } rb = GetComponent<Rigidbody> ();

82 C# Script Update () method is called once per frame and that s where our animation goes. For Desktop, Input are arrow keys and for phones, Input is Accelerometer by default. What moves the Player is the force, which is the product of movement vector and the speed.

83 C# Script void Update () { float movehorizontal = Input.GetAxis ("Horizontal"); float movevertical = Input.GetAxis ("Vertical"); Vector3 movement = new Vector3 (movehorizontal, 0.0f, movevertical); } rb.addforce (movement * speed); Try to run it now (hit play button in Unity). Nothing happens. Why?

84 C# Script What is the value of speed? Well, select Player and observe PlayerScript in Inspector: Speed is 0 and so is the force. Set it to 10, run again and have fun!

85 It s alive!

86 Camera Our camera is static. How to have camera following our Player? Select Main Camera and in Inspector lift it up (Y) and rotate by 45 degrees (X).

87 Camera To control camera, we need a script. Select Main Camera, Add Component, New Script. Name: CameraController, Type: C-Sharp The offset of type Vector3 is constant - difference between Player and Main Camera. To update camera s position we simply add player s position and offset in Update () method ( or LateUpdate () as recommended)

88 CameraController.cs using UnityEngine; using System.Collections; public class CameraController : MonoBehaviour { public GameObject player; private Vector3 offset; void Start () { offset = transform.position - player.transform.position; } } void LateUpdate () { transform.position = player.transform.position + offset; }

89 Camera The last thing we need to do here is to assign Player to our CameraController. Select Main Camera and drag Player into the Player field in Inspector. Run and observe that camera follows player even if player falls of the edge of ground.

90 It s alive!

91 Walls It s quite easy (and frustrating) for that ball to drop of the plain. We are going to add walls by creating an empty game object Walls, resetting it and adding four walls to it. To create a new Wall, add new 3D game object Cube, rename it to West Wall, reset and drop into parent Walls

92 Walls Select West Wall and in inspector scale it to (0.5, 2, 20.5) and position to (-10, 0, 0)

93 Walls To create the East Wall, select West Wall, Edit, Duplicate and change its position to (10, 0, 0) Similarly, create North Wall - position: (0, 0, 10), rotation (0, 90, 0) and South Wall - position (0, 0, -10), rotation (0, 90, 0)

94 Walls

95 Collectable Objects Create new Cube, rename it to Pickup and reset Transform. Select Cube and Edit, Lock View to Selected. Player is in the way. Select Player and in Inspector, deselect checkbox in front of the Player

96 Tranforms Transform cube - position (0, 0.5, 0), rotation (45, 45, 45), scale (0.5, 0.5, 0.5) We also want our Cube to permanently rotate - for that, we need a script. Pickup selected, in Inspector add component, new script, C-Sharp, name: Rotator

97 Tranforms using UnityEngine; using System.Collections; public class Rotator : MonoBehaviour { // Use this for initialization void Start () { } } // Update is called once per frame void Update () { transform.rotate ( new Vector3 (15, 30, 45) * Time.deltaTime); }

98 Prefabs Let s create more pickup objects. In order to do so we will create Prefab (template for game object) Start by selecting Project and create new folder Prefabs. Drag the Pickup object from Hierarchy into Prefabs folder Also in Hierarchy, create an empty object name Pickups and drag Pickup into it

99 Prefabs Change perspective to top (right click on gizmo) Select Pickup from hierarchy and change its orientation from local to global

100 Prefabs Now duplicate ( D) and arrange Pickups

101 Materials again Let s change the color of our Pickups. In Assets, duplicate existing material (background) and in Albedo change its color. Now simply drag newly created material into Prefabs/ Pickup. Bingo!

102 It s alive!

103 Collisions In order to pick up objects we have to detect when collision occurs between Player and Pickup Open PlayerController.cs and add method void OnTriggerEnter(Collider other) void OnTriggerEnter(Collider other) { if (other.gameobject.comparetag ("Pick Up")) { other.gameobject.setactive (false); } }

104 Collisions For this code to work we need to associate tag Pick Up with our Pickup prefab. Select Pickup from Prefabs and in Inspector, Tag select Add Tag In the dialog, add tag, name: Pick Up

105 Collisions Back in Inspector, prefab Pickup select, choose Pick Up tag. Observe that the same tag is associated with all pickup objects. If we run the game now, there is not much difference - Player still bounces agains Pickups. Select Pickup from Prefabs and in Inspector, Box Collider, check Is Trigger checkbox.

106 Physics Optimization Calculating collisions with rotating cubes (static cache) per each frame can be computationally expensive. The solution is to add rigid body to our Pickup objects. Select Pickup from Prefabs, Add Component, Physics, Ridid Body. This will turn static coliders into dynamic coliders.

107 Physics Optimization Run. Oops! All Pickups drop trough the floor (gravity pulls them down. They are triggers and do not collide with the floor) One might be tempted to disable gravity in Rigidbody component

108 Physics Optimization This would work in our example, but not in general, since rigid body would still react to physics forces. The solution is to declare Pickup as Kinematic - now it won t react to physics forces.

109 Display Text (Score) In order to keep track of the score we need to enhance our PlayerController. Select Scripts, PlayerController. To keep track of picked up cube we ll declare: private int count; And set it to zero in our Start () method.

110 Display Text (Score) Count is incremented in our OnTriggerEnter method: void OnTriggerEnter(Collider other) { if (other.gameobject.comparetag ("Pick Up")) { other.gameobject.setactive (false); count++; } }

111 Display Text (Score) To display count, we ll need to use Unity s UI Tool Set. From Hierarchy, Create UI Text

112 Display Text (Score) Observe that Unity also created Text s parent object Canvas as EventSystem game object. All UI elements must be children of the Canvas element. Rename Text to Count Text and in Inspector change its color to white, reset position.

113 Display Text (Score) We ll position our text into the upper left corner of the screen using Rect transform Anchor Presets Shift + Alt presents more options. Padding and size can be changed in Pos X, Pos Y, Pos X, Width, Height fields of Rect transform

114 Display Text (Score) To wire up UI Text to display count value, open PlayerController script. At the top of the script we need to declare namespace: using UnityEngine.UI;

115 Display Text (Score) Next we declare reference to our UI Text component: public Text counttext; And initialize it in Start () method: counttext.text = "Count: " + count.tostring ();

116 Display Text (Score) Same code is executed in OnTriggerEvent () method after counter is incremented. Finally, in Unity editor, select Player and observe that Count Text field has been created. From Hierarchy, drag and drop Count Text into None (Text) field.

117 Run. Display Text (Score)

118 Game Over Let s create another UI Text (name: Win Text, color: white, position: center top) As before, in PlayerController.cs,declare Text variable public Text wintext; Initialize it to an empty string: counttext.text = "";

119 Game Over After counter is incremented, see if it s 12 - total number of pickup objects. if(count >= 12) wintext.text = "You win!"; Back in Unity editor, select Player and drag and drop Win Text from Hierarchy into Win Text placeholder.

120 Build and Run From the main menu, select File, Build Settings Give it a name

121 Build and Run