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[Lesson 2] Get Start Scratch

2.1 About Scratch

Scratch is an online coding language and development environment that allows users to create interactive stories, games, animations, and multimedia projects. It is a free and open-source software that runs on Windows, Mac, and Linux operating systems.

2.1.1 Learn Scratch

• To learn what is scratch, please view: Introduce scratch
• If you have no experience of Scratch, please start fromGet start of scratch tutorial
• More scratch tutorial on “Collection of Coding Cards”

2.1.2 Scratch practices

10 blocks will help you to start with scratch. You can view the pdf file and practice it.

• 10 blocks

2.2 Control and condition

In Scratch, control and condition are used to make the program to make decision or to repeat the same action multiple times.

2.2.1 Loop

• repeat
  • when you need do the same actions multiple times
• forever
  • when you want repeat do something endless
  • use wait to slow down the loop
  • use ‘say’ or ‘think’ block to display the loop

2.2.2 Condition

• if then

• if then else

• condition loop : repeat until

• use “wait until” to pause the forever with condition

• stop the forever loop

2.2.3 Practice Loop and Condition

Let’s practice using loops and conditions in Scratch to make the Cat sprite do fun things!

Practice Task

• Spinning Cat: When you press the mouse key, the Cat on the stage will keep spinning.
• Changing Costumes: When you release the mouse key, the Cat will show a new costume every 1 second.

How to Do It

1. Spinning Cat:
   • Drag an “if” block into the scripting area.
   • Inside the “if” block, add a “mouse down?” block to check if the mouse key is pressed.
   • Add a “forever” block and put a “turn 15 degrees” block inside it.
   • This will make the Cat spin continuously when the mouse key is pressed.
2. Changing Costumes:
   • Drag another “if” block into the scripting area.
   • Inside this “if” block, add a “mouse up?” block to check if the mouse key is released.
   • Add a “wait 1 second” block and a “next costume” block inside the “if” block.
   • This will make the Cat show a new costume every second when the mouse key is released.

2.3 Animation in Scratch

2.3.1 Animation with Sprite from Library

• Sprite: Next Costume:
  • Drag a “next costume” block into the scripting area.
  • Change the sprite’s costume to create simple animations.
• FPS: Frame per Second:
  • Scratch can show up to 30 frames per second (FPS).
  • Use this code to find out the FPS of Scratch:

2.3.2 Drawing your costume

• Draw Your Own Costume:

• Use the drawing tools in Scratch to create your own costumes.

• Convert Between Vector and Bitmap:
  • Bitmaps and vectors are two different types of graphics.
  • Vector Graphics: Use mathematical formulas to draw lines and curves.
  • Bitmap Graphics: Store the color of each pixel.
• the different of Vector and Bitmap

2.3.3 Animation with code

• Moving by change location
  • Use code to move your sprite around the stage.

  

• Turn around
  • Make your sprite turn in different directions.

  

• Glide
  • Make your sprite move smoothly.

  

• Change color and other graphic effect
  • Use code to change the color and other graphic effect of your sprite.

  

• Change size
  • Use code to change the size of your sprite.

  

2.4 Scratch practices and project

2.4.1 Practices

• Simple animation in sprit Build A Band
• Animation with Drawing Orange Square Purple Circle
• Animation It’s alive
• Animation with music Music video

2.4.1 Project of this class

• Base on the about me
• Build a Scratch project to introduce yourself.
• Make sure need use all different types of Animation in scratch
• Make sure use Condition and loop in you project

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