Page 82 - Learn To Program With Scratch

Figure 3-16: The SpotLight sprite and its script

The script first sets the sprite’s ghost effect to 30 to make it transparent
so that it won’t obscure the backdrop. The script then sends this sprite one
layer back, which places the light beam behind the dancer. The sprite is then
positioned so that the light beam appears to be emanating from the spotlight
(see Figure 3-10). You’ll have to choose the x- and y-coordinates based on
your drawing. After that, the script commands the light beam to follow the
dancer (using the point towards command) and change its color forever.
Once you’re done adding the spotlight, the application should be com-
plete. Click the green flag to watch your dance party in action! In addi-
tion to the music and the dancing, you should also see the Ball, Board, and
SpotLight sprites changing color as though real disco lights are in action.
In the next section, we’ll look at a different application that highlights
many of the graphic effects we studied in this chapter.

Fireworks
Fireworks_ Another application that lends itself naturally to the graphics blocks and
NoCode .sb2 other concepts discussed in this chapter is an animated fireworks scene.
In this section, you’ll make a simple firework animation that floods the sky
with colorful sparks. The firework rockets will explode at random times,
producing sparks that fall as though acted upon by gravity and fade slowly
with time, as illustrated in Figure 3-17.

Clones of the Rocket sprite
will explode and produce
colorful sparks that fall to the
ground.

The City sprite

Figure 3-17: The fireworks animation in action

60 Chapter 3
www.it-ebooks.info