Monster Maker III

Review — where we got to 5 min

• Each graphic effect is a number you can set.
• A forever loop copies (colour) into set [color v] effect to (colour) on every part.
• A slider on the Stage lets the player choose the number.
• clear graphic effects goes under the green flag.

Quick-fire

The colour slider says 150. The head and body are orange, but the legs are still green. What is missing?

Today’s Topic 3 min

• One broadcast [dance v], four sprites receiving it
• A size pulse that always comes back
• Layers: go to [front v] layer and go [backward v] (1) layers
• A ghost fade between two poses
• broadcast [trick v] and wait to do one move after another

Learning outcome

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

1. Start several sprites with one message and keep them in time.
2. Move a sprite in front of or behind another with layer blocks.
3. Fade a group of sprites out and in together, changing pose in between.

Learnt — a dance in parts 27 min

A dancing monster made of four sprites is four dancers. They need one signal to start, and the same beat to stay together.

1 · One message, four dancers

Add the Drum from the library. When it is clicked, it sends one message.

when this sprite clicked
broadcast [dance v]
            

Every sprite with when I receive [dance v] starts at that moment. Each part does its own move.

when I receive [dance v]
go to x: (0) y: (65)
repeat (8)
  change y by (12)
  wait (0.25) seconds
  change y by (-12)
  wait (0.25) seconds
end
              

when I receive [dance v]
set size to (100) %
repeat (8)
  change size by (10)
  wait (0.25) seconds
  change size by (-10)
  wait (0.25) seconds
end
              

when I receive [dance v]
go to x: (0) y: (-110)
repeat (8)
  change x by (10)
  wait (0.25) seconds
  change x by (-10)
  wait (0.25) seconds
end
              

when I receive [dance v]
point in direction (90)
repeat (8)
  turn ccw (40) degrees
  wait (0.25) seconds
  turn cw (40) degrees
  wait (0.25) seconds
end
              

All four wait 0.25 and repeat 8 times. So all four take 4 seconds, and they finish together.

2 · Why only the body pulses

Level 1’s pulse grew a whole sprite on the beat. Here the parts touch each other. A head that grows 10% also grows downwards, into the body. So each part gets a move that keeps the monster in one piece.

3 · Layers

Every sprite sits on its own layer, like sheets of paper in a pile. The sprite on top covers the ones below. The sprite you made last starts on top.

Our pile, from the bottom: Legs, Head, Body, Arm. The Arm is right above the Body. One step back puts it behind.

Now make the arm go round like a windmill. Over the top, it is in front. Round the bottom, it goes behind.

when flag clicked
go to [front v] layer
point in direction (90)
forever
  repeat (6)
    turn ccw (30) degrees
    wait (0.1) seconds
  end
  go [backward v] (1) layers
  repeat (6)
    turn ccw (30) degrees
    wait (0.1) seconds
  end
  go [forward v] (1) layers
end
            

4 · The ghost trick

A magic trick: the monster fades away, changes pose while nobody can see, and fades back. It is three steps on every part.

1. Fade out: change [ghost v] effect by (5), 20 times. That reaches 100.
2. Change pose, while invisible.
3. Fade in: change [ghost v] effect by (-5), 20 times. Back to 0.

A variable pose says which pose to take. The Stage flips it between 1 and 2, then sends trick.

when I receive [trick v]
repeat (20)
  change [ghost v] effect by (5)
end
if <(pose) = (2)> then
  point in direction (0)
else
  point in direction (90)
end
repeat (20)
  change [ghost v] effect by (-5)
end
              

when flag clicked
set [pose v] to (1)
forever
  wait (1.5) seconds
  if <(pose) = (1)> then
    set [pose v] to (2)
  else
    set [pose v] to (1)
  end
  broadcast [trick v] and wait
end
              

Basic — build the dance 25 min

Open your maker from last lesson. Choose a monster you like, then add the dance to it.

Step 1 — an arm

1. Paint a new sprite called Arm. Draw it from the middle of the drawing area outwards, to the right.
2. Put it at the body’s right shoulder.
3. Give it the green-flag stack below.

when flag clicked
go to x: (55) y: (-15)
go to [front v] layer
point in direction (90)
clear graphic effects
              

when flag clicked
go to x: (0) y: (65)
set size to (100) %
clear graphic effects
switch costume to [three eyes v]
              

Step 2 — the drum

1. Add the Drum sprite and its sound Drum Bass1.
2. Make it keep the beat on the dance message.

when I receive [dance v]
repeat (8)
  switch costume to [drum-b v]
  start sound [Drum Bass1 v]
  wait (0.25) seconds
  switch costume to [drum-a v]
  wait (0.25) seconds
end
            

Step 3 — three dancers

1. Give Head, Body and Legs their dance stacks from Learnt.
2. Click the drum. All three should stop at the same moment as the drum.

Step 4 — the windmill

1. Give the Arm the dance stack below: the windmill, twice round.
2. Check it goes behind the body at the bottom.

when I receive [dance v]
point in direction (90)
repeat (2)
  repeat (6)
    turn ccw (30) degrees
    wait (0.17) seconds
  end
  go [backward v] (1) layers
  repeat (6)
    turn ccw (30) degrees
    wait (0.17) seconds
  end
  go [forward v] (1) layers
end
            

Step 5 — the trick, after the dance

1. Make a variable pose. On the Stage, set it to 1 on the green flag.
2. Give every part its trick stack. Legs only fade out and in.
3. Change the Drum’s click stack to the one below.

when this sprite clicked
broadcast [dance v] and wait
if <(pose) = (1)> then
  set [pose v] to (2)
else
  set [pose v] to (1)
end
broadcast [trick v] and wait
            

One click, four dancers

Your own dance, started by one message.

• One click starts every part.
• Every part does a different move.
• They all finish at the same moment.
• At the end, the monster is back in one piece.

In front, then behind

An arm that goes round the monster, not only past it.

• Over the top, the arm is in front.
• Round the bottom, it is behind the body.
• The green flag always starts it in front.

Now you see it

The ghost trick, with your own second pose.

• Every part fades out together.
• The pose changes while it is invisible.
• Every part fades back in, fully solid.
• The next trick goes back to the first pose.

when I receive [trick v]
repeat (20)
  change [ghost v] effect by (5)
end
if <(pose) = (2)> then
  set size to (115) %
else
  set size to (100) %
end
repeat (20)
  change [ghost v] effect by (-5)
end
            

The full routine

A show with four moves, one after another, from one click.

• Dance, then spin, then the ghost trick, then a bow.
• Each move starts only when the one before has finished.
• The spin uses last lesson’s whirl effect, and comes back to 0.
• The head says thank you in the bow.

when this sprite clicked
broadcast [dance v] and wait
broadcast [spin v] and wait
if <(pose) = (1)> then
  set [pose v] to (2)
else
  set [pose v] to (1)
end
broadcast [trick v] and wait
broadcast [bow v]
                

when I receive [spin v]
repeat (20)
  change [whirl v] effect by (18)
end
repeat (20)
  change [whirl v] effect by (-18)
end
                

Summary 5 min

• One broadcast can start many sprites. Each one runs its own script.
• The same wait and the same repeat keep them in time.
• Start every move from home, so a second click cannot break the monster.
• Layers decide who covers whom. go [backward v] (1) layers steps back past one sprite.
• The green flag does not reset layers or effects. Your scripts must.

Layer

A sprite’s place in the pile. Higher layers cover lower ones.

Receiver

A sprite with a when I receive hat for a message.

Pose

How the parts are arranged at one moment.

Ghost

The see-through effect. 0 is solid, 100 is invisible.

Hand in

Save your dancing monster and share the link. Next lesson the monster opens a shop, and customers start ordering.