In this video I’m going to give you an overview of Scratch.
We’ll go over how Scratch works, the user interface and some basic concepts.
This is not meant to be an in depth video about Scratch. My idea is to give you enough information so that you know your way around the program. Then, as we proceed in the following videos, we’ll take a deeper dive into the specifics.
Scratch is available at https://scratch.mit.edu.
To use Scratch, start by creating an signing into your account.
Then you’ll be able to create as many projects as you want. These will remain saved in your online account under My Stuff.
To create a new project press the Create button on the main menu. It will open a new blank project called Untitled.
In this section you have the Game Window and related controls.
The Game Window has a resolution of 480x360px with the center point in the middle. The horizontal X axis goes from -240 to 240 from left to right. And the vertical Y axis goes from -180 to 180 from bottom to top.
Note: understanding the coordinate system is a must to position the sprites in the game.
On the top right-hand corner, you can switch between the default, compact or maximized Game Window.
Note: Please note that maximizing the window does not change the resolution. It only scales the content.
On the top left hand corner you have the buttons to start and stop the game.
The Game Window shows exactly how the game looks when you share it with others. So when you press the Start button it shows you exactly what other players will see when they play your game.
Sprites are the main entity in a Scratch game. They are basically the images that you can program in your game.
To add new sprites use the menu on the bottom right hand corner:
Since we’ll be creating our sprites outside of Scratch we’ll end up using only the Upload your own option. But using the catalogue is always a good solution when you don’t want to spend time drawing your own designs.
To remove a Sprite from the game, you can press the Bin on the top right hand corner of the sprite.
Note: Please make sure you actually want to remove it because it won’t ask you to confirm it. But if you accidentally delete it, you can always recover it using the Edit menu on the top bar.
The bottom part of the section is a list of all the sprites you currently have in the game. When you create a new project, it already has a single sprite - the Scratch cat. But as you add new ones this list will keep growing.
The top part is contextual to the selected Sprite on the bottom. And here you have multiple properties of the sprite:
The Sprite’s name.
You can name your Sprites whatever you want. But make sure you choose a descriptive name. Some blocks use the sprite names and having recognizable ones makes it easier to select them.
The X and Y position of the Sprite in the Game Window.
These values correspond to the coordinate system we discussed before. You can change the Sprite position by changing these values or click and drag the sprite on the Game Window.
Toggle the Sprite visibility.
This is useful to hide Sprites that shouldn’t be visible from the game start and that we'll toggle later in the game.
Despite being called Size it actually means the Sprite scale. By default all Sprites have a scale of 100%. Meaning that they will have exactly the same size of the image.
But for example, if you change this value to 50, the sprite will be half of the original size. And if you change it to 200 it will be twice the original size.
What direction the sprite is “facing”.
By default, all Sprites start “facing” right, which correspond to a rotation value of 90 degrees.
Besides changing the rotation value, you can also set the rotation mode:
Note: The rotation is something to keep in mind when using the Move block.
The Backdrop is the game background. It’s always behind all the Sprites in the game. And just like with the Sprites, you can select images from the catalogue, draw or upload your own.
You can also program the Backdrop but it’s more limited in the amount of actions it can perform.
This section is always contextual to what’s currently selected. Meaning that what you see and change here it’s applied to the selected Sprite or Backdrop.
Both Sprites and Backdrop can have Code, Costumes and Sounds.
Code is how you add behaviors to the Sprites and Backdrops. Scratch has multiple blocks organized by categories to program those behaviors. The game logic results from combining and assigning different blocks to the entities that you have in your game.
On the left side you have all the categories and its corresponding blocks. The area on the right side is where you have code that’s currently applied to the selected entity.
To add a block, click and drag from the left side and release it on the right side. And to remove it do the opposite. If you right-click the block you can also delete and duplicate it.
To connect blocks drag a block close to an existing one until it highlights the connection area. Then release it to create the connection.
To disconnect blocks, drag a block away until it disconnects. Please note that when you drag a connected block it moves the entire sequence connected to it. You can use this move the blocks inside the area or disconnect entire groups of blocks.
As you are adding more and more blocks you’ll need to pan and zoom the right area:
Note: you can also use the zoom controls on the bottom right-hand corner.
Costumes are the Sprite images.
All Sprites must have at least one Costume, but can also have more than one. You can use multiple Costumes to create animations.
On the left side you have the list of Costumes and on the right side you can edit the corresponding images.
*Note: please make sure you give your Costumes proper names because some blocks will use them."
Besides Code and Costumes, a Sprite and Backdrop can also have associated sounds.
This section is like the Costumes but instead of working with images you are working with sounds. A Sprite can have one or more sounds and you can edit each one of them.
Scratch also has a catalogue of sounds to choose from. But you can upload your owns or even record new sounds in Scratch.
The Backpack is an area where you can add groups of connected blocks to reuse throughout the project. It is also possible to drag a group of blocks from one Sprite directly to another one. But adding them to the Backpack make it easier to share among multiple entities.
The Main Menu has options related to Scratch and the project itself:
By default your project is private but you have the option to share it with the Community.
Each project has a Project Page with the Name, Instructions and some other Notes and Credits. This is the page other users will see when accessing your project and where they’ll try your project.
Besides trying the project you can also see how other projects were done by clicking See Inside. This let’s you inspect how the project code.
You can also Remix the project. This creates a copy of the project and adds it to your own collection so that you can change it and make it your own.