Monster Maker II — Scratch L2 Lesson 26

Learnt27 min · seven effects, set or change, sliders
Basic25 min · paint the maker
Challenge 1–327 min · four colours, two sliders, a clean start
Extrabonus · a mood dial

WHAT IT SHOULD LOOK LIKE

What we are making today. Two numbers on the Stage, and a monster that follows them. Colour 50 turns every part blue at once.

colour 0

colour 50

panels run left to right

Review — where we got to 5 min

The monster is three sprites: Head, Body and Legs.
(costume [number v]) reads which costume is on.
switch costume to ((costume [number v]) + (1)) is the ▶ arrow.
Each part copies its number into a variable: head, body, legs.

Quick-fire

The head wears costume 4. You press ▶. What is the head’s number now?

Reveal the answer

1. There is no costume 5, so Scratch goes round to the first one. One eye again.

Today’s Topic 3 min

The seven graphic effects
set [color v] effect to (50) and change [color v] effect by (25)
clear graphic effects
Three ways to show a variable, and the slider
A forever loop that copies a variable into an effect

Learning outcome

By the end of this lesson you will be able to:

Use all seven effects and say what each one does.
Choose between set and change, and clear effects on the green flag.
Drive an effect on every part from one slider on the Stage.

Learnt — effects as numbers 27 min

In Level 1 you changed a colour on the beat, a bit more each time. Today an effect is a number you choose. The player picks it, and the monster follows.

1 · Seven effects

Looks has two effect blocks. Each has a dropdown with seven effects in it.

Effect	What you see	Numbers to try
`set [color v] effect to (50)`	Every colour shifts round the rainbow.	0 to 200. At 200 it is back where it started.
`set [fisheye v] effect to (100)`	The middle bulges out, like a fish-eye lens.	Below 0 pinches it in instead.
`set [whirl v] effect to (150)`	The middle twists round.	Below 0 twists the other way.
`set [pixelate v] effect to (60)`	The sprite turns into big square blocks.	Bigger number, bigger blocks.
`set [mosaic v] effect to (25)`	Lots of small copies, in a grid.	Bigger number, more copies.
`set [brightness v] effect to (50)`	Lighter, towards white.	−100 is black. 100 is white.
`set [ghost v] effect to (70)`	See-through.	0 solid, 100 gone.

The embed runs all seven, one after another. It uses clear graphic effects between each one, so you only ever see one at a time.


clear graphic effects
set [whirl v] effect to (150)
say [whirl 150]
wait (1.4) seconds

One of the seven, on the Head. The other six are the same four blocks with their own effect and number. Body and Legs do it without the say.

Runs here in the page. Nothing to install.

How to use this: Click the green flag to start it. Nothing else to press — watch it through, then use ↺ Reset to run it again.

All seven effects on the whole monster. The head names each one as it happens.

2 · Set or change?


change [color v] effect by (25)

Adds 25 to whatever it is now. Press it twice: 50.


set [color v] effect to (50)

Goes to 50, whatever it was. Press it twice: still 50.

Change is for something that keeps moving, like lights on a beat. Set is for a colour you want to name. Our monster needs names.

Colour number	Our monster turns
0	green (no change)
50	blue
100	pink
150	orange
200	green again

These colours are for our green monster. A red sprite gets different colours from the same numbers, because the effect shifts whatever colour is there.

3 · One number for the whole monster

Three parts means three sprites to paint. Instead of telling each one, put the colour in a variable. Each part copies it into its effect, over and over.

In Variables, make colour, For all sprites.
On the Stage, build when [2 v] key pressed and set [colour v] to (50).
Give each part the forever loop below.
Press 2. All three parts turn blue together.


when flag clicked
go to x: (0) y: (65)
switch costume to [two eyes v]
forever
  set [color v] effect to (colour)
end

On the Head. Body and Legs have the same loop.


when [2 v] key pressed
set [colour v] to (50)

On the Stage. Keys 1, 3 and 4 set 0, 100 and 150.

WHAT IT SHOULD LOOK LIKE

The number lives in one variable. Every part reads it, so every part turns together. Nobody tells the parts to change.

colour is 50

Runs here in the page. Nothing to install.

How to use this: Click the green flag, then click the stage once and press 1, 2, 3 or 4 to pick a colour.

Press 1, 2, 3 or 4. The whole monster turns green, blue, pink or orange — and pressing the same key twice changes nothing.

4 · A slider on the Stage

A variable’s readout on the Stage can look three ways. Right-click it to choose.

Readout	What it shows	Good for
normal readout	The name and the number, small	Checking your code while you build
large readout	Only the number, big	A score the player should see
slider	The name, the number and a bar you drag	Letting the player choose the number

Make a second variable, wobble, For all sprites.
Right-click the colour readout on the Stage. Choose slider.
Right-click it again. Choose change slider range. Type 0 and 200.
Do the same for wobble, with 0 and 200.
Drag a slider. The number changes. The monster does not — yet.

The slider only changes the variable. The forever loop is what copies it into the effect. Add a second line for wobble, using whirl.


when flag clicked
go to x: (0) y: (65)
switch costume to [two eyes v]
clear graphic effects
forever
  set [color v] effect to (colour)
  set [whirl v] effect to (wobble)
end

On the Head. One loop, two effects, two variables.

Runs here in the page. Nothing to install.

How to use this: Click the green flag, then click the stage once. Press → and ← to change colour, ↑ and ↓ to change wobble.

The embed cannot show a slider, so arrow keys move the numbers instead. → adds 25 to colour, ← takes 25 away. ↑ and ↓ do the same to wobble.


when [right arrow v] key pressed
change [colour v] by (25)

Only in the embed, on the Stage: a stand-in for dragging the slider. ← ↑ ↓ have one each. In your own project, use the sliders.

Basic — paint the maker 25 min

Open last lesson’s monster maker. You are adding to it, not starting again.

Runs here in the page. Nothing to install.

How to use this: Click the green flag. Click a part or a ◀ ▶ arrow on the stage to change a part. Click the stage once, then press → ← for colour and ↑ ↓ for wobble.

What you are aiming at: last lesson's maker, with colour and wobble. The keys stand in for the two sliders.

Step 1 — the two variables

Make colour and wobble, both For all sprites.
Turn both readouts into sliders, range 0 to 200.
Drag them to the top-left, under head, body and legs.

Step 2 — the head’s loop

On the Head’s green-flag stack, add clear graphic effects at the bottom.
Add a forever loop under it, with the two set-effect blocks inside.
Drag the colour slider. Only the head should change.

Step 3 — body and legs

Drag the clear block and the loop onto the Body sprite in the Sprite list. That copies them.
Do the same onto Legs.
Put each copy at the bottom of that part’s own green-flag stack.
Drag the colour slider. All three should change together.

Step 4 — a clean start

Click the Stage. Add a green-flag stack that sets colour and wobble to 0.
Drag both sliders somewhere strange. Press the green flag.
The sliders jump back to 0 and the monster is plain again.


when flag clicked
go to x: (0) y: (65)
switch costume to [one eye v]
set [head v] to (costume [number v])
clear graphic effects
forever
  set [color v] effect to (colour)
  set [whirl v] effect to (wobble)
end

The Head’s green-flag stack, finished.


when flag clicked
set [colour v] to (0)
set [wobble v] to (0)

On the Stage.

One part will not change colour.

That part has no forever loop, or its loop is in a stack that never runs. Click the part in the Sprite list and look for the loop under its green flag.

The monster flashes every colour at once.

A change [color v] effect by (colour) is in the loop. Swap it for the set block.

The slider only goes up to 100.

100 is the starting range. Right-click the slider, choose change slider range, and set the maximum to 200.

The eyes change colour too.

White, grey and black hardly change with the colour effect. If your eyes are coloured, they will change with the rest. Draw them white with a dark middle.

CHALLENGE 1 · L2-26-M1🪙 30 Adcoins8 min

Four named colours

Four keys, four colours for the whole monster.

1 green, 2 blue, 3 pink, 4 orange.
All three parts change together.
Pressing the same key again changes nothing.

WHAT IT SHOULD LOOK LIKE

Challenge 1 — four keys, four colours, and the same key always gives the same colour.

press 1

press 2 · then press 2 again

panels run left to right

Done when: you press 2, 2, 2 and the monster stays the same blue, then 3 gives pink straight away.

CHALLENGE 2 · L2-26-M2🪙 50 Adcoins9 min

Two sliders

The player dials in the monster themselves.

A colour slider from 0 to 200.
A wobble slider that twists the monster.
Both sliders move every part at once.

WHAT IT SHOULD LOOK LIKE

Challenge 2 — two sliders that move the whole monster, every part together.

drag colour to 50

Done when: you drag each slider from one end to the other and no part is ever left behind.

Teacher note

The classic slip is a loop on the Head only. It is worth letting a pupil find it by dragging, rather than warning them.

CHALLENGE 3 · L2-26-M3🪙 70 Adcoins10 min

A third dial, and a clean start

Add one more slider of your choice, and make the green flag undo everything.

A third slider drives fisheye, pixelate or brightness.
The green flag puts all three sliders back to 0.
The green flag clears every effect on every part.

WHAT IT SHOULD LOOK LIKE

Challenge 3 — however strange it gets, the green flag brings back the plain monster.

sliders all over the place

green flag

panels run left to right

Done when: you drag all three sliders to strange numbers, press the flag, and see a plain green monster with three sliders at 0.

Teacher reveal — a fisheye dial on the Body


when flag clicked
go to x: (0) y: (-25)
switch costume to [round v]
set [body v] to (costume [number v])
clear graphic effects
forever
  set [color v] effect to (colour)
  set [whirl v] effect to (wobble)
  set [fisheye v] effect to (fisheye)
end

Plus set [fisheye v] to (0) on the Stage’s green flag. A brightness dial wants a range of −100 to 100; ask the pupil why before they find out.

EXTRA MISSION · L2-26-MX🪙 100 Adcoinsbonus

A mood dial

One slider called mood, from 1 to 3. Each mood is a mix of effects, and the monster shows it.

Mood 1, happy: no effects at all.
Mood 2, cold: blue and a bit see-through.
Mood 3, cross: red and puffed up.

Runs here in the page. Nothing to install.

How to use this: Click the green flag, then click the stage once and press 1, 2 or 3 to set the mood.

Keys 1, 2 and 3 stand in for the mood slider. Happy, cold, cross — and 1 brings it back.

Teacher reveal — one part’s mood loop


when flag clicked
go to x: (0) y: (65)
switch costume to [four eyes v]
forever
  clear graphic effects
  if <(mood) = (2)> then
    set [color v] effect to (50)
    set [ghost v] effect to (40)
  end
  if <(mood) = (3)> then
    set [color v] effect to (133)
    set [fisheye v] effect to (60)
  end
end

Clearing inside the loop does not flicker: the whole pass runs before the Stage is drawn. Colour 133 is red on our green monster.

Summary 5 min

Looks has seven graphic effects, and each one is a number.
set goes to a number. change adds to it. Named colours need set.
clear graphic effects belongs under every green flag that uses an effect.
A slider lets the player choose a variable’s value.
A forever loop copies the variable into the effect, on every part.

Graphic effect: A change to how a sprite looks, without changing its costume.
Slider: A readout with a bar the player drags to set the variable.
Range: The smallest and biggest numbers a slider can reach.
Readout: A variable shown on the Stage. Scratch also calls it a monitor.

Hand in

Save your maker and share the link with your teacher. Next lesson the monster dances.

Learnt27 min · seven effects, set or change, sliders
Basic25 min · paint the maker
Challenge 1–327 min · four colours, two sliders, a clean start
Extrabonus · a mood dial

WHAT IT SHOULD LOOK LIKE

What we are making today. Two numbers on the Stage, and a monster that follows them. Colour 50 turns every part blue at once.

colour 0

colour 50

panels run left to right

Review — where we got to 5 min

The monster is three sprites: Head, Body and Legs.
(costume [number v]) reads which costume is on.
switch costume to ((costume [number v]) + (1)) is the ▶ arrow.
Each part copies its number into a variable: head, body, legs.

Quick-fire

The head wears costume 4. You press ▶. What is the head’s number now?

Reveal the answer

1. There is no costume 5, so Scratch goes round to the first one. One eye again.

Today’s Topic 3 min

The seven graphic effects
set [color v] effect to (50) and change [color v] effect by (25)
clear graphic effects
Three ways to show a variable, and the slider
A forever loop that copies a variable into an effect

Learning outcome

By the end of this lesson you will be able to:

Use all seven effects and say what each one does.
Choose between set and change, and clear effects on the green flag.
Drive an effect on every part from one slider on the Stage.

Learnt — effects as numbers 27 min

In Level 1 you changed a colour on the beat, a bit more each time. Today an effect is a number you choose. The player picks it, and the monster follows.

1 · Seven effects

Looks has two effect blocks. Each has a dropdown with seven effects in it.

Effect	What you see	Numbers to try
`set [color v] effect to (50)`	Every colour shifts round the rainbow.	0 to 200. At 200 it is back where it started.
`set [fisheye v] effect to (100)`	The middle bulges out, like a fish-eye lens.	Below 0 pinches it in instead.
`set [whirl v] effect to (150)`	The middle twists round.	Below 0 twists the other way.
`set [pixelate v] effect to (60)`	The sprite turns into big square blocks.	Bigger number, bigger blocks.
`set [mosaic v] effect to (25)`	Lots of small copies, in a grid.	Bigger number, more copies.
`set [brightness v] effect to (50)`	Lighter, towards white.	−100 is black. 100 is white.
`set [ghost v] effect to (70)`	See-through.	0 solid, 100 gone.

The embed runs all seven, one after another. It uses clear graphic effects between each one, so you only ever see one at a time.


clear graphic effects
set [whirl v] effect to (150)
say [whirl 150]
wait (1.4) seconds

One of the seven, on the Head. The other six are the same four blocks with their own effect and number. Body and Legs do it without the say.

Runs here in the page. Nothing to install.

How to use this: Click the green flag to start it. Nothing else to press — watch it through, then use ↺ Reset to run it again.

All seven effects on the whole monster. The head names each one as it happens.

2 · Set or change?


change [color v] effect by (25)

Adds 25 to whatever it is now. Press it twice: 50.


set [color v] effect to (50)

Goes to 50, whatever it was. Press it twice: still 50.

Change is for something that keeps moving, like lights on a beat. Set is for a colour you want to name. Our monster needs names.

Colour number	Our monster turns
0	green (no change)
50	blue
100	pink
150	orange
200	green again

These colours are for our green monster. A red sprite gets different colours from the same numbers, because the effect shifts whatever colour is there.

3 · One number for the whole monster

Three parts means three sprites to paint. Instead of telling each one, put the colour in a variable. Each part copies it into its effect, over and over.

In Variables, make colour, For all sprites.
On the Stage, build when [2 v] key pressed and set [colour v] to (50).
Give each part the forever loop below.
Press 2. All three parts turn blue together.


when flag clicked
go to x: (0) y: (65)
switch costume to [two eyes v]
forever
  set [color v] effect to (colour)
end

On the Head. Body and Legs have the same loop.


when [2 v] key pressed
set [colour v] to (50)

On the Stage. Keys 1, 3 and 4 set 0, 100 and 150.

WHAT IT SHOULD LOOK LIKE

The number lives in one variable. Every part reads it, so every part turns together. Nobody tells the parts to change.

colour is 50

Runs here in the page. Nothing to install.

How to use this: Click the green flag, then click the stage once and press 1, 2, 3 or 4 to pick a colour.

Press 1, 2, 3 or 4. The whole monster turns green, blue, pink or orange — and pressing the same key twice changes nothing.

4 · A slider on the Stage

A variable’s readout on the Stage can look three ways. Right-click it to choose.

Readout	What it shows	Good for
normal readout	The name and the number, small	Checking your code while you build
large readout	Only the number, big	A score the player should see
slider	The name, the number and a bar you drag	Letting the player choose the number

Make a second variable, wobble, For all sprites.
Right-click the colour readout on the Stage. Choose slider.
Right-click it again. Choose change slider range. Type 0 and 200.
Do the same for wobble, with 0 and 200.
Drag a slider. The number changes. The monster does not — yet.

The slider only changes the variable. The forever loop is what copies it into the effect. Add a second line for wobble, using whirl.


when flag clicked
go to x: (0) y: (65)
switch costume to [two eyes v]
clear graphic effects
forever
  set [color v] effect to (colour)
  set [whirl v] effect to (wobble)
end

On the Head. One loop, two effects, two variables.

Runs here in the page. Nothing to install.

How to use this: Click the green flag, then click the stage once. Press → and ← to change colour, ↑ and ↓ to change wobble.

The embed cannot show a slider, so arrow keys move the numbers instead. → adds 25 to colour, ← takes 25 away. ↑ and ↓ do the same to wobble.


when [right arrow v] key pressed
change [colour v] by (25)

Only in the embed, on the Stage: a stand-in for dragging the slider. ← ↑ ↓ have one each. In your own project, use the sliders.

Basic — paint the maker 25 min

Open last lesson’s monster maker. You are adding to it, not starting again.

Runs here in the page. Nothing to install.

How to use this: Click the green flag. Click a part or a ◀ ▶ arrow on the stage to change a part. Click the stage once, then press → ← for colour and ↑ ↓ for wobble.

What you are aiming at: last lesson's maker, with colour and wobble. The keys stand in for the two sliders.

Step 1 — the two variables

Make colour and wobble, both For all sprites.
Turn both readouts into sliders, range 0 to 200.
Drag them to the top-left, under head, body and legs.

Step 2 — the head’s loop

On the Head’s green-flag stack, add clear graphic effects at the bottom.
Add a forever loop under it, with the two set-effect blocks inside.
Drag the colour slider. Only the head should change.

Step 3 — body and legs

Drag the clear block and the loop onto the Body sprite in the Sprite list. That copies them.
Do the same onto Legs.
Put each copy at the bottom of that part’s own green-flag stack.
Drag the colour slider. All three should change together.

Step 4 — a clean start

Click the Stage. Add a green-flag stack that sets colour and wobble to 0.
Drag both sliders somewhere strange. Press the green flag.
The sliders jump back to 0 and the monster is plain again.


when flag clicked
go to x: (0) y: (65)
switch costume to [one eye v]
set [head v] to (costume [number v])
clear graphic effects
forever
  set [color v] effect to (colour)
  set [whirl v] effect to (wobble)
end

The Head’s green-flag stack, finished.


when flag clicked
set [colour v] to (0)
set [wobble v] to (0)

On the Stage.

One part will not change colour.

That part has no forever loop, or its loop is in a stack that never runs. Click the part in the Sprite list and look for the loop under its green flag.

The monster flashes every colour at once.

A change [color v] effect by (colour) is in the loop. Swap it for the set block.

The slider only goes up to 100.

100 is the starting range. Right-click the slider, choose change slider range, and set the maximum to 200.

The eyes change colour too.

White, grey and black hardly change with the colour effect. If your eyes are coloured, they will change with the rest. Draw them white with a dark middle.

CHALLENGE 1 · L2-26-M1🪙 30 Adcoins8 min

Four named colours

Four keys, four colours for the whole monster.

1 green, 2 blue, 3 pink, 4 orange.
All three parts change together.
Pressing the same key again changes nothing.

WHAT IT SHOULD LOOK LIKE

Challenge 1 — four keys, four colours, and the same key always gives the same colour.

press 1

press 2 · then press 2 again

panels run left to right

Done when: you press 2, 2, 2 and the monster stays the same blue, then 3 gives pink straight away.

CHALLENGE 2 · L2-26-M2🪙 50 Adcoins9 min

Two sliders

The player dials in the monster themselves.

A colour slider from 0 to 200.
A wobble slider that twists the monster.
Both sliders move every part at once.

WHAT IT SHOULD LOOK LIKE

Challenge 2 — two sliders that move the whole monster, every part together.

drag colour to 50

Done when: you drag each slider from one end to the other and no part is ever left behind.

Teacher note

The classic slip is a loop on the Head only. It is worth letting a pupil find it by dragging, rather than warning them.

CHALLENGE 3 · L2-26-M3🪙 70 Adcoins10 min

A third dial, and a clean start

Add one more slider of your choice, and make the green flag undo everything.

A third slider drives fisheye, pixelate or brightness.
The green flag puts all three sliders back to 0.
The green flag clears every effect on every part.

WHAT IT SHOULD LOOK LIKE

Challenge 3 — however strange it gets, the green flag brings back the plain monster.

sliders all over the place

green flag

panels run left to right

Done when: you drag all three sliders to strange numbers, press the flag, and see a plain green monster with three sliders at 0.

Teacher reveal — a fisheye dial on the Body


when flag clicked
go to x: (0) y: (-25)
switch costume to [round v]
set [body v] to (costume [number v])
clear graphic effects
forever
  set [color v] effect to (colour)
  set [whirl v] effect to (wobble)
  set [fisheye v] effect to (fisheye)
end

Plus set [fisheye v] to (0) on the Stage’s green flag. A brightness dial wants a range of −100 to 100; ask the pupil why before they find out.

EXTRA MISSION · L2-26-MX🪙 100 Adcoinsbonus

A mood dial

One slider called mood, from 1 to 3. Each mood is a mix of effects, and the monster shows it.

Mood 1, happy: no effects at all.
Mood 2, cold: blue and a bit see-through.
Mood 3, cross: red and puffed up.

Runs here in the page. Nothing to install.

How to use this: Click the green flag, then click the stage once and press 1, 2 or 3 to set the mood.

Keys 1, 2 and 3 stand in for the mood slider. Happy, cold, cross — and 1 brings it back.

Teacher reveal — one part’s mood loop


when flag clicked
go to x: (0) y: (65)
switch costume to [four eyes v]
forever
  clear graphic effects
  if <(mood) = (2)> then
    set [color v] effect to (50)
    set [ghost v] effect to (40)
  end
  if <(mood) = (3)> then
    set [color v] effect to (133)
    set [fisheye v] effect to (60)
  end
end

Clearing inside the loop does not flicker: the whole pass runs before the Stage is drawn. Colour 133 is red on our green monster.

Summary 5 min

Looks has seven graphic effects, and each one is a number.
set goes to a number. change adds to it. Named colours need set.
clear graphic effects belongs under every green flag that uses an effect.
A slider lets the player choose a variable’s value.
A forever loop copies the variable into the effect, on every part.

Graphic effect: A change to how a sprite looks, without changing its costume.
Slider: A readout with a bar the player drags to set the variable.
Range: The smallest and biggest numbers a slider can reach.
Readout: A variable shown on the Stage. Scratch also calls it a monitor.

Hand in

Save your maker and share the link with your teacher. Next lesson the monster dances.