This document provides an introduction to scripting with Unity using Javascript. It aims to teach the fundamentals of scripting through a tutorial that has the user write scripts to control player input and movement, connect variables via the GUI, access components from other scripts, instantiate game objects, and use debugging techniques like Debug.Log(). The tutorial is estimated to take 2 hours to complete and covers important concepts like naming conventions, using Time.deltaTime to control movement speed, and exposing variables to tweak values in the inspector.
Introduction to Game Programming: Using C# and Unity 3D - Chapter 3 (Preview)noorcon
We go deeper into the concept of GameObjefts. How to create them, how to add components. Scripts are discussed and shown how they can be converted into components and attached to the GameObject. Finally the concept of Prefab and parent/child relationship are discussed.
Getting to know unity, special thanks to JUST and my friend Ruba Al-Saa'di and Dr. Natheer.
We are waiting for Patented a small request caused a technology revolution.
An introductory presentation about the Unity game engine given at GarageGeeks HQ in 2012, meant to bring programmers who have no game development experience up to speed with Unity
Introduction to Game Programming: Using C# and Unity 3D - Chapter 3 (Preview)noorcon
We go deeper into the concept of GameObjefts. How to create them, how to add components. Scripts are discussed and shown how they can be converted into components and attached to the GameObject. Finally the concept of Prefab and parent/child relationship are discussed.
Getting to know unity, special thanks to JUST and my friend Ruba Al-Saa'di and Dr. Natheer.
We are waiting for Patented a small request caused a technology revolution.
An introductory presentation about the Unity game engine given at GarageGeeks HQ in 2012, meant to bring programmers who have no game development experience up to speed with Unity
Unity 3d is a popular game engine used to design games for mobiles,xbox etc.
It was developed by unity technologies and it was useful to those who want to start game designing
Unity is a cross-platform game engine developed by Unity Technologies,[4] first announced and released in June 2005 at Apple Inc.'s Worldwide Developers Conference as an OS X-exclusive game engine. As of 2018, the engine has been extended to support 27 platforms.[5] The engine can be used to create both three-dimensional and two-dimensional games as well as simulations for desktops and laptops, home consoles, smart TVs, and mobile devices. Several major versions of Unity have been released since its launch, with the latest stable version being Unity 2018.2.2, released on August 10, 2018.[6]
Unity gives users the ability to create games in both 2D and 3D, and the engine offers a primary scripting API in C#, for both the Unity editor in the form of plugins, and games themselves, as well as drag and drop functionality. Prior to C# being the primary programming language used for the engine, it previously supported Boo, which was removed in the Unity 5[7] release, and a version of JavaScript called UnityScript, which was deprecated in August 2017 after the release of Unity 2017.1 in favor of C#.[8]
The engine has support for the following graphics APIs: Direct3D on Windows and Xbox One; OpenGL on Linux, macOS, and Windows; OpenGL ES on Android and iOS; WebGL on the web; and proprietary APIs on the video game consoles. Additionally, Unity supports the low-level APIs Metal on iOS and macOS and Vulkan on Android, Linux, and Windows, as well as Direct3D 12 on Windows and Xbox One.
Cocos2d is a well known open source software framework on game industry. It is is a 2D game framework built upon the OpenGL ES API’s.
In this session, I will talk about a hierarchical structures of an Cocos2d node and scenes. Also Cocos2d Graphic User Interface, Physical System, Audio, Particle System and Scene Transition technique will be shown. Finally this session will show various branches of Cocos2d open source projects including Cocos2d-x, Cocos2d-Swift, Cocos2d-html5, and Cocos2d-xna.
Lecture 6 from a course on Mobile Based Augmented Reality Development taught by Mark Billinghurst and Zi Siang See on November 29th and 30th 2015 at Johor Bahru in Malaysia. This lecture provides an introduction to Unity 3D. Look for the other 9 lectures in the course.
Introductory tutorial using Virtual Reality in Unity3d version 5. Included are simple steps to activate Virtual Reality in Unity3d version 5; optimize the virtual reality experience; using and including the standard Unity3d version 5 first person controller prefab; and creating a dynamic day night cycle.
Unity 3d is a popular game engine used to design games for mobiles,xbox etc.
It was developed by unity technologies and it was useful to those who want to start game designing
Unity is a cross-platform game engine developed by Unity Technologies,[4] first announced and released in June 2005 at Apple Inc.'s Worldwide Developers Conference as an OS X-exclusive game engine. As of 2018, the engine has been extended to support 27 platforms.[5] The engine can be used to create both three-dimensional and two-dimensional games as well as simulations for desktops and laptops, home consoles, smart TVs, and mobile devices. Several major versions of Unity have been released since its launch, with the latest stable version being Unity 2018.2.2, released on August 10, 2018.[6]
Unity gives users the ability to create games in both 2D and 3D, and the engine offers a primary scripting API in C#, for both the Unity editor in the form of plugins, and games themselves, as well as drag and drop functionality. Prior to C# being the primary programming language used for the engine, it previously supported Boo, which was removed in the Unity 5[7] release, and a version of JavaScript called UnityScript, which was deprecated in August 2017 after the release of Unity 2017.1 in favor of C#.[8]
The engine has support for the following graphics APIs: Direct3D on Windows and Xbox One; OpenGL on Linux, macOS, and Windows; OpenGL ES on Android and iOS; WebGL on the web; and proprietary APIs on the video game consoles. Additionally, Unity supports the low-level APIs Metal on iOS and macOS and Vulkan on Android, Linux, and Windows, as well as Direct3D 12 on Windows and Xbox One.
Cocos2d is a well known open source software framework on game industry. It is is a 2D game framework built upon the OpenGL ES API’s.
In this session, I will talk about a hierarchical structures of an Cocos2d node and scenes. Also Cocos2d Graphic User Interface, Physical System, Audio, Particle System and Scene Transition technique will be shown. Finally this session will show various branches of Cocos2d open source projects including Cocos2d-x, Cocos2d-Swift, Cocos2d-html5, and Cocos2d-xna.
Lecture 6 from a course on Mobile Based Augmented Reality Development taught by Mark Billinghurst and Zi Siang See on November 29th and 30th 2015 at Johor Bahru in Malaysia. This lecture provides an introduction to Unity 3D. Look for the other 9 lectures in the course.
Introductory tutorial using Virtual Reality in Unity3d version 5. Included are simple steps to activate Virtual Reality in Unity3d version 5; optimize the virtual reality experience; using and including the standard Unity3d version 5 first person controller prefab; and creating a dynamic day night cycle.
These slides are part of a course about interactive objects in games. The lectures cover some of the most widely used methodologies that allow smart objects and non-player characters (NPCs) to exhibit autonomy and flexible behavior through various forms of decision making, including techniques for pathfinding, reactive behavior through automata and processes, and goal-oriented action planning. More information can be found here: http://tinyurl.com/sv-intobj-2013
Learn C# Programming - Data Types & Type ConversionEng Teong Cheah
Add C# syntax to your vocabulary by exploring fundamental building blocks: data types. In addition, learn about basic topics, such as naming conventions and data type conversions.
Introduction to Unity3D and Building your First GameSarah Sexton
In Phase One, we will cover the basics of using the Unity editor’s interface, customizing the workspace, building a 3D environment, and adding sound effects.
In Phase Two, we will import a player character asset, learn about Animator Controllers, make animations, set up physics and gravity, and add player movement scripts.
In Phase Three, we will set up our Camera and write a script to make the camera follow our player character.
Study: The Future of VR, AR and Self-Driving CarsLinkedIn
We asked LinkedIn members worldwide about their levels of interest in the latest wave of technology: whether they’re using wearables, and whether they intend to buy self-driving cars and VR headsets as they become available. We asked them too about their attitudes to technology and to the growing role of Artificial Intelligence (AI) in the devices that they use. The answers were fascinating – and in many cases, surprising.
This SlideShare explores the full results of this study, including detailed market-by-market breakdowns of intention levels for each technology – and how attitudes change with age, location and seniority level. If you’re marketing a tech brand – or planning to use VR and wearables to reach a professional audience – then these are insights you won’t want to miss.
DSC RNGPIT - Getting Started with Game Development Day 1DeepMevada1
DSC RNGPIT had organized a session on Game Development where students where introduced to the basics of Game Development and the Unity Game Engine Interface.
Students were also introduced to the game development flowchart where an example of Flappy Bird was given, and were also given a task to make flowcharts for their games.
Introduction to Game Programming: Using C# and Unity 3D - Chapter 2 (Preview)noorcon
The reader is introduced to the Unity 3D IDE. The basic sections of the IDE are defined and explained. The reader is show how to navigate within the IDE and create GameObjects. How to perform transformations and etc… The Inspector Window is also discussed.
Introduction to html5 game programming with ImpactJsLuca Galli
A brief introduction to HTML5 Game Development that describes and use ImpactJs, one of the most famous and complete frameworks for HTML5 Games, mostly for learning purposes. The benefits of HTML5 Games are described, along with the importance of using a Framework and describing in details the ImpactJs Game Engine (no code provided, since it's proprietary). Two different games are coded on the fly during the lesson, while providing tips and suggestions. The Reference, Bibliography and Resources section provide useful pointers for beginners.
HoloLens Unity Build Pipelines on Azure DevOpsSarah Sexton
Developers of Unity UWP apps: stop wasting time compiling builds in Unity, then Visual Studio, then manually deploying. Save time with an automated pipeline! Create builds from start to finish, implement Unit Tests, save every build artifact, and even distribute using App Center! Learn how to create a Azure DevOps pipeline that can be used to build any Mixed Reality solution.
Applications use in Java GUIThe Java GUI consists of a separate, .pdfakshay1213
Applications use in Java GUI:
The Java GUI consists of a separate, automous task execution thread called the \"event loop\".
Every action that affects the GUI, e.g. calls to repaint the screen or to manipulate the properties
of a GUI component, or is a result of something happening to the GUI, e.g. the user clicks the
mouse or hits a key, is encapsulated in the form of an \"event\" that is placed into a queue for the
event loop to process. The result of processing an event may be a manipulation of the bits of
color on the screen or it may result in calls to methods in the developer\'s code.
1.A Java GUI application uses the standard Java components GUI component set, Swing, and is
deployed to the desktop.
2.The Swing GUI Builder in NetBeans IDE simplifies the GUI development process and enables
you to visually create Java GUI applications using pre-installed Swing and AWT components.
3.JavaFX is a rich set of graphics and media packages that enables developers to design, create,
test, debug, and deploy rich client applications (RIAs) that behave consistently across multiple
platforms.
Similariti Between JAVA and JAVA GUI:
I think in many cases the overhead incurred to run a JVM is acceptable because of the
functionality the code base
provides.So winding back a bit, the reason that functionality can exist with Java has much to do
with the language/environment which frees programmers from a lot of resource management and
allows them to focus
more on plugging together components. Time to market and all that jazz.Like a lot of interpreted
languages, Java\'s development cycle ispretty excellent I think. A programmer can get a fairly
complicatedapplication off the ground quickly due to a number of things broughtabout both by
the interp-language development paradigm that allows for
immediate detection of errors and compile-and-test-as-you-code sessions.I think those are the
kinds of things which has made Java popular.
Some Java applications that you can install and play with on your own desktop machine:
1.Eclipse
2.NetBeans
3.jEdit
4.OpenOffice
Java is used in
JAVA GUI:
The Java GUI system however is a legacy issue where the system underwent a large-scale
upgrade , so some of the classes involved are spread over the (relatively) older java.awt packages
and the newer javax.swing packages. In general, if the class name starts with \"J\", then it is in
the Swing package. Since some functionality appears to be duplicated in the Swing packages,
such as frames and buttons, always use the Swing component over the older AWT components
when there is a choice.
Commonly Used Methods in GUI Components:
void setPreferredSize(int width, int height) :sets the size of a component to be used when the
layout manager is able to use that size, e.g. there is enough room. Some layout managers always
ignore the size setting of a component because the size is under other constraints..
String getText(), void setText(String s) :accessor methods for the text of labels, button.
this presentation serve as an introduction to Angular JavaScript framework and also touch on some basic modern JavaScript, front-end development basics.
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
1. Introduction to scripting with Unity
Scripting is an essential part of Unity as it
defines the behaviour of your game. This
tutorial will introduce the fundamentals of
scripting using Javascript. No prior knowledge
of Javascript or Unity is required.
Time to complete: 2 hours.
Author: Graham McAllister
Contents 1. Aims of this tutorial
Scripting is how the user defines a game’s behaviour (or
1. Aims of this tutorial rules) in Unity. The recommended programming
language for Unity is Javascript, however C# or Boo
2. Prerequisites can also be used. This tutorial will cover the
3. Naming conventions fundamentals of scripting in Unity and also introduce key
elements of the Application Programming Interface (API).
4. Player Input You can think of the API as code that has already been
5. Connecting variables written for you which lets you concentrate on your game
design and also speeds up development time.
6. Accessing components
A good understanding of these basic principles is
7. Instantiate essential in order to harness the full power of Unity.
8. Debugging
9. Common Script Types
2. Prerequisites
This tutorial focuses on the scripting element of Unity, it
is assumed you are already familiar with Unity’s interface
(if not you should read the Unity GUI tutorial).
In order to make scripting easier to understand, it is
preferable to have a code editor that has syntax
highlighting support for Javascript. This means that
reserved words (syntax used by Javascript itself) are
coloured differently than user defined words. One such
editor is SubEthaEdit.
NB: any text that requires the user to take an action
begins with a ‘-’.
2. 3. Naming Conventions
Before we begin, it is worth mentioning some conventions in Unity.
Variables - begin with a lowercase letter. Variables are used to store information about
any aspects of a game’s state.
Functions - begin with an uppercase letter. Functions are blocks of code which are
written once and can then be reused as often as needed.
Classes - begin with an uppercase letter. These can be thought of as collections of
functions.
Tip: When reading example code or the Unity API, pay close attention to the first letter of
words. This will help you better understand the relationship between objects.
4. Player Input
For our first program we’re going to allow the user
to move around in a simple game world.
Setting the scene
- Start Unity.
Firstly, let’s create a surface for the user to walk on.
The surface we’re going to use is a flattened cube
shape.
- Create a cube and scale its x,y,z dimensions to 5, 0.1, 5 respectively, it should now
resemble a large flat plane. Rename this object ‘Plane’ in the Hierarchy View.
- Create a 2nd cube and place it at the centre of this plane. If you can’t see the objects in
your Game View, alter the main camera so they’re visible. Rename the object to
Cube1.
- You should also create a point light and place it above the cubes so that they’re more
easily visible.
- Save the scene by selecting File->Save As and give the game a name.
Our first script
We’re now ready to start game programming. We’re going to allow the player to move
around the game world by controlling the position of the main camera. To do this we’re
going to write a script which will read input from the keyboard, then we attach (associate)
the script with the main camera (more on that in the next section).
- Begin by creating an empty script. Select Assets->Create->Javascript and rename this
script to Move1 in the Project Panel.
- Double-click on the Move1 script and it will open with the Update() function already
inserted (this is default behaviour), we’re going to insert our code inside this function.
Any code you insert inside the Update() function will be executed every frame.
2
3. In order to move a game object in Unity we need to alter the position property of its
transform, the Translate function belonging to the transform will let us do this. The
Translate function takes 3 parameters, x, y and z movement. As we want to control the
main camera game object with the cursor keys, we simply attach code to determine if the
cursor keys are being pressed for the respective parameters:
function Update () {
transform.Translate(Input.GetAxis("Horizontal"), 0, Input.GetAxis("Vertical"));
}
The Input.GetAxis() function returns a value between -1 and 1, e.g. on the horizontal axis,
the left cursor key maps to -1, the right cursor key maps to 1.
Notice the 0 parameter for the y-axis as we’re not interested in moving the camera
upwards. The Horizontal and Vertical axis are pre-defined in the Input Settings, the names
and keys mapped to them can be easily changed in Edit->Project Settings->Input.
- Open the Move1 Javascript and type in the above code, pay close attention to capital
letters.
Attaching the script
Now that our first script is written, how do we tell Unity which game object should have this
behaviour? All we have to do is to attach the script to the game object which we want to
exhibit this behaviour.
- To do this, first click on the game object that you wish to have the behaviour as defined
in the script. In our case, this is the Main Camera, and you can select it from either the
Hierarchy View or the Scene View.
- Next select Components->Scripts->Move1 from the main menu. This attaches the
script to the camera, you should notice that the Move1 component now appears in the
Inspector View for the main camera.
Tip: You can also assign a script to an game object by dragging the script from the
Project View onto the object in the Scene View.
- Run the game (press the play icon at the lower left hand corner), you should be able to
move the main camera with the cursor keys or W,S,A,D.
You probably noticed that the camera moved a little too fast, let’s look at a better way to
control the camera speed.
Delta time
As the previous code was inside the Update() function, the camera was moving at a
velocity measured in meters per frame. It is better however to ensure that your game
objects move at the more predictable rate of meters per second. To achieve this we
multiply the value returned from the Input.GetAxis() function by Time.deltaTime and also
by the velocity we want to move per second:
3
4. var speed = 5.0;
function Update () {
var x = Input.GetAxis("Horizontal") * Time.deltaTime * speed;
var z = Input.GetAxis("Vertical") * Time.deltaTime * speed;
transform.Translate(x, 0, z);
}
- Update the Move1 script with the above code.
Notice here that the variable speed is declared outside of the function Update(), this is
called an exposed variable, as this variable will appear in the Inspector View for whatever
game object the script is attached to (the variable gets exposed to the Unity GUI).
Exposing variables are useful when the value needs to be tweaked to get the desired
effect, this is much easier than changing code.
5. Connecting Variables
Connecting variables via the GUI is a very powerful
feature of Unity. It allows variables which would
normally be assigned in code to be done via drag and
drop in the Unity GUI. This allows for quick and easy
prototyping of ideas. As connecting variables is done
via the Unity GUI, we know we always need to expose
a variable in our script code so that we can assign the
parameter in the Inspector View.
We’ll demonstrate the connecting variables concept
by creating a spotlight which will follow the player
(Main Camera) around as they move.
- Add a spotlight to the Scene View. Move it if necessary so it’s close to the other game
objects.
- Create a new Javascript and rename it to Follow.
Let’s think what we want to do. We want our new spotlight to look at wherever the main
camera is. As it happens, there’s a built in function in Unity to do this, transform.LookAt().
If you were beginning to think ‘how do I do this?’ and were already imagining a lot of code,
then it’s worth remembering to always check the Unity API for a function that already
exists. We could also make a good guess at looking in the ‘transform’ section of the API
as we’re interested in altering the position or rotation of a game object.
Now we come to the connecting variables section; what do we use as a parameter for
LookAt()? Well we could hardcode a game object, however we know we want to assign
the variable via the GUI, so we’ll just use an exposed variable (of type Transform). Our
Follow.js script should look like this:
var target : Transform;
function Update () {
transform.LookAt(target);
}
4
5. - Attach the script to the spotlight and notice when the component gets added, the
“target” variable is exposed.
- With the spotlight still selected, drag the Main Camera from the Hierarchy View onto the
“target” variable in the Inspector View. This assigns the target variable, i.e. the
spotlight will now follow the Main Camera. If we wanted the spotlight to follow a
different game object we could just drag in a different object (as long as it was of type
Transform of course).
- Play the game. If you watch the Scene View you should see the spotlight following the
Main Camera around. You may want to change the position of the spotlight to improve
the effect.
6. Accessing Components
As a game object can have multiple scripts (or other components) attached, it is often
necessary to access other component’s functions or variables. Unity allows this via the
GetComponent() function.
We’re now going to add another script to our spotlight which will make it look at Cube1
whenever the jump button (spacebar by default) is pressed.
Let’s think about this first, what do we want to do:
1. Detect when the jump button has been pressed.
2. When jump has been pressed make the spotlight look at Cube1. How do we do this?
Well, the Follow script contains a variable “target” whose value determines which game
object the spotlight should look at. We need to set a new value for this parameter. We
could hardcode the value for the cube (see the section ‘Doing it with code’ later), however
we know that exposing the variable and assigning this via the GUI is a better way of doing
this.
- Create a new Javascript and name it Switch. Add the following code to Switch.js:
var switchToTarget : Transform;
function Update () {
if (Input.GetButtonDown("Jump"))
GetComponent(Follow).target = switchToTarget;
}
Notice in particular how Follow is the parameter to GetComponent(), this returns a
reference to the Follow script which we can then use to access its “target” variable.
- Add the Switch script to the spotlight and assign Cube1 to the switchToTarget
parameter in the Inspector View.
- Run the game. Move around and verify that the spotlight follows you as usual, then hit
the spacebar and the spotlight should focus on the Cube1.
Doing it with code
Earlier in the tutorial we mentioned that it would be possible to assign the variables via
code (as opposed to the Unity GUI), let’s take a look at how you would do that.
5
6. Remember this is only for comparison, assigning
variables via the GUI is the recommended approach.
The problem we were interested in earlier was how
do we tell the spotlight to look at Cube1 when the
jump button was pressed. Our solution was to
expose a variable in the Switch script which we could
then assign by dropping Cube1 onto it from the Unity
GUI. There are two main ways to do this in code:
1. Use the name of the game object.
2. Use the tag of the game object.
1. Game object name
A game object’s name can be seen in the Hierarchy View. To use this name with code we
use it as a parameter in the GameObject.Find() function. So if we want the jump button to
switch the spotlight from Main Camera to Cube1, the code is as follows:
function Update () {
if (Input.GetButtonDown("Jump"))
{
var newTarget = GameObject.Find("Cube").transform;
GetComponent(Follow).target = newTarget;
}
}
Notice how no variable is exposed as we name it directly in code. Check the API for more
options using Find().
2. Game object tag
A game object’s tag is a string which can be used to identify a component. To see the
built-in tags click on the Tag button in the Inspector View, notice you can also create your
own. The function for finding a component with a specific tag is GameObject.FindWithTag
() and takes a string as a parameter. Our complete code to do this is:
function Update () {
if (Input.GetButtonDown("Jump"))
{
var newTarget = GameObject.FindWithTag("Cube").transform;
GetComponent(Follow).target = newTarget;
}
}
6
7. 7. Instantiate
It is often desirable to create objects during run-time (as the game is being played). To do
this, we use the Instantiate function.
Let’s show how this works by instantiating (creating) a new game object every time the
user presses the fire button (either the left mouse button or left ctrl on the keyboard by
default).
So what do we want to do? We want the user to move around as usual, and when they hit
the fire button, instantiate a new object. A few things to think about:
1. Which object do we instantiate?
2. Where do we instantiate it?
Regarding which object to instantiate, the best way of solving this is to expose a variable.
This means we can state which object to instantiate by using drag and drop to assign a
game object to this variable.
As for where to instantiate it, for now we’ll just create the new game object wherever the
user (Main Camera) is currently located whenever the fire button is pressed.
The Instantiate function takes three parameters; (1) the object we want to create, (2) the
3D position of the object and (3) the rotation of the object.
The complete code to do this is as follows (Create.js):
var newObject : Transform;
function Update () {
if (Input.GetButtonDown("Fire1")) {
Instantiate(newObject, transform.position, transform.rotation);
}
}
Don’t forget that transform.position and transform.rotation are the position and rotation of
the transform that the script is attached to, in our case this will be the Main Camera.
However, when an object is instantiated, it is usual for that object to be a prefab. We’ll
now turn the Cube1 game object into a prefab.
- Firstly, let’s create an empty prefab. Select Assets->Create->Prefab. Rename this
prefab to Cube.
- Drag the Cube1 game object from the Hierarchy View onto the Cube prefab in the
Project view. Notice the prefab icon changes.
Now we can create our Javascript code.
- Create a new Javascript and name it Create. Insert the above code.
- Attach this script to the Main Camera and assign the Cube prefab to the newObject
variable of Main Camera.
- Play the game and move around as usual. Each time the fire button is clicked (LMB or
left ctrl) and you should notice a new cube appearing.
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8. 8. Debugging
Debugging is the skill of finding and fixing human errors in your code (ok let’s call them
mistakes!). Unity provides help via the Debug class, we’ll now look at the Debug.Log()
function.
Log
The Log() function allows the user to send a message to the Unity Console. Reasons for
doing this might include:
1. To prove that a certain part of the code is being reached during run-time.
2. To report the status of a variable.
We’ll now use the Log() function to send a message to the Unity Console when the user
clicks the fire button.
- Open the Create script and add the following line after the ‘Instantiate’ code inside the
‘if’ block:
Debug.Log("Cube created");
- Run the game and click the fire button, you should see a line appear at the bottom of
the Unity GUI saying “Cube created”, you can click on this to examine the Unity
Console.
Watch
Another useful feature for debugging is exposing a private variable. This makes the
variable visible in the Inspector View when the Debug mode is selected, but it cannot be
edited.
To demonstrate this, we’ll expose a private variable to count the number of cubes that we
instantiate.
- Open the Create script again and add two lines:
(1) Add a private variable called cubeCount
(2) Increment this variable whenever a cube is instantiated.
The complete code is a follows (Create.js):
var newObject : Transform;
private var cubeCount = 0;
function Update () {
if (Input.GetButtonDown("Fire1")) {
Instantiate(newObject, transform.position, transform.rotation);
Debug.Log("Cube created");
cubeCount++;
}
}
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9. - Run the game and click the fire button to create some cubes. Notice in the Inspector
View how the cubeCount variable is incremented whenever a new cube is instantiated.
Notice also how the number appears greyed out, this denotes that it’s a read-only
variable (cannot be edited).
9. Common script types
Whenever a new Javascript is created, by default it contains an Update() function. This
section will discuss other common options available, simply replace the name of the
Update() function with one from the list below.
FixedUpdate()
Code placed inside this function is executed at regular intervals (a fixed framerate). It is
common to use this function type when applying forces to a Rigidbody.
// Apply a upwards force to the rigid body every frame
function FixedUpdate () {
rigidbody.AddForce (Vector3.up);
}
Awake()
Code inside here is called when the script is initialized.
Start()
This is called before any Update() function, but after Awake(). The difference between the
Start () and Awake() functions is that the Start() function is only called if the script is
enabled (if its checkbox is enabled in the Inspector View).
OnCollisionEnter()
Code inside here is executed when the game object the script belongs to collides with
another game object.
OnMouseDown()
Code inside here is executed when the mouse hovers over a game object which contains
a GUIElement or a Collider.
// Loads the level named "SomeLevel" as a response
// to the user clicking on the object
function OnMouseDown () {
Application.LoadLevel ("SomeLevel");
}
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10. OnMouseOver()
Code inside here is executed when the mouse hovers over a game object which contains
a GUIElement or a Collider.
// Fades the red component of the material to zero
// while the mouse is over the mesh
function OnMouseOver () {
renderer.material.color.r -= 0.1 * Time.deltaTime;
}
Check the Unity API for more information on all of these functions.
Summary
This tutorial has introduced the essential scripting concepts in Unity. You
should now read other Unity tutorials or try experimenting yourself!
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