Scratch

Look Blocks

Rajat Garg

— 3 min read
Look Blocks

1. Switch Costume & Next Costume Blocks

Costumes are different appearances of a sprite. A sprite can have multiple costumes to show different looks, like a character walking, dancing, or changing expressions.

  • Switch Costume Block:
    • Instantly changes the sprite’s look to a specific costume.
    • You must select a costume name (e.g., "Running Pose") from the costume list.
  • Next Costume Block:
    • Automatically moves to the next costume in the sprite’s list.
    • If a sprite has 3 costumes, it will switch from Costume 1 → Costume 2 → Costume 3 → Costume 1 (loops back).

Example 1:
If you only want the sprite to switch between two specific costumes, you can alternate between them – Let’s do it for a Balloon sprite:

Example 2:
If you want the sprite to cycle through all its costumes, use Next Costume instead:

How to Teach?

  • Show students a sprite with multiple costumes.
  • Demonstrate how switching costumes can create a walking or dancing effect.

2. Switch Backdrop & Next Backdrop Blocks

A backdrop is the background of the Scratch stage. It helps in setting the scene for animations, games, and stories.

  • Switch Backdrop Block:
    • Instantly changes the background to a specific backdrop.
  • Next Backdrop Block:
    • Moves to the next backdrop in the backdrop list.

Example 1: Switching the backdrop to “Night City”.

Example 2: Auto-Changing Backgrounds with Next Backdrop

How to Teach?

Demonstrate how to transition between mountain and beach backdrops.

3. Set Size & Change Size Blocks

Sprites can increase or decrease in size using size blocks.

  • Set Size Block:
    • Defines a sprite’s size as a percentage of its original size.
  • Change Size Block:
    • Increases or decreases the size by a specific amount.

Example 1: The Sprite size increases to 1.5 times its normal size.

Example 2: The sprite grows and shrinks using spacebar using change size.

How to Teach?

  • Show how changing size can create a zoom-in/out effect.
  • Demonstrate using both Set Size and Change Size blocks.
  • Ask students to make a sprite grow when a key is pressed.


Class Implementation: Talking Character with Music

Objective:

Create a sprite that changes costumes, changes backdrop and changes size.

Steps:

  1. Choose a sprite and add at least two costumes.
  2. Use the Next Costume block inside a Forever loop to animate.
  1. Use the Change Size block to grow/shrink the sprite.
  1. Add a backdrop change when the sprite is clicked.


✅ Expected Outcome: The sprite continuously animates, plays sounds, and responds to user interaction.

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