Retro-lab

- Index

Lesson 1: Basics

Install Unity

At the page https://store.unity.com/ you can choose the version to download. For beginners, the personal (and free) edition is more than enough. Install it, by following the instructions. It is an easy task.

Create a new project

Once Unity has been installed, run it and start a new project. Select the location you want to store data, type the name, and select 2D option. Note: Be sure you have write access to your project's folder to avoid Access Denied errors.

First of all, you have to know that you can import 2D assets already prepared by Unity, to simplify your work. There are two way to get them. You can go on the project panel and right, and then select "import Package" in the context menu.

Alternatively, you can go to the Unity store at the following url: https://assetstore.unity.com/ . I suggest that you use the second option: updated standard assets are available and you can browse them by category and have a preview.

You can use pre-made assets to understand how they are structured and obviously you can copy from them. As preliminary action, we can create a few folders for our project by right-clicking on the panel and selecting "create folder".

I usually create the following ones: audio, prefabs, scenes, scripts, sprites.

At this point save the current scene in the namesake folder: it will be our first level.

Project setup

The background

When you create a new scene, by default Unity will create the scene and a "Main Camera" object. In this game, I want to have scrolling backgrounds with parallax. To do that, firstly I add a background to the camera. This one will be a fixed background associated to the camera and always present on the screen. It will also be the farthest. Scale it to adapt it to the screen size.

Then you should create one or more additional backgrounds that will move and create the parallax effect. In fact, the background (as well as the grounds) can be layered to make a depth effect. To do that, follow three simple steps:

Create an empty object

add backgrounds

change layers' order

If you switch to the 3D visualization, the layer concept will be more clear.

At this point we have to create the parallax effect. Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, We want to create scrolling background images to produce the feeling of parallax. We have 3 backgrounds at the moment: the one associated to the camera (which is fixed), buildings1 and buildings2. We will make the last two scrolling.
Basically the concept is very simple: we are going to create an array of objects (2 in this case, but we can add more) to be parallaxed:

and for each of them we are going to use a scale index for scrolling. The effect will be backgrounds scrolling at different speed, thus producing the desired behavior.

You can download the sprites used in this lesson at this link: DOWNLOAD