User Guide

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3. In the Scripts Area, remove the go to front and go
back 6 layers blocks from the when I receive
StartGame script.
4. In the Scripts Area, click Costumes, and then click
Edit.
5. Using a single, solid color (for example, bright
green), draw shapes over the areas that the player
sprite cannot walk.
6. Using the Eraser tool and Selection tool, delete the
parts of the image where the player can walk. These
areas must be transparent.
Repeat this process for the other background sprites – for the
second mask, copy the second the background; for the third
mask, copy the third background, and so on. Name the masks
ML1M2, ML1M3, ML1M4, ML1M5 respectively.
Because you copied most of the blocks from the background
sprites, these masks will scroll with the background. It does not
matter what layer they appear on as you will not see them.
Scratch cannot detect collisions between hidden objects, and so
use the ghost effect to make the masks invisible.
In the when I receive Level1 scripts on each of the masks:
1. In the Blocks Palette, click Looks.
2. Drag a set color effect to block over to the Scripts
Area, and snap it into position above the show
block.
3. On the set color effect to block, click color and
then click ghost.
4. Click the white box, and change the value to 100.
Then create the wall-sensing sprite:
Make sure all of the areas in your mask are joined. Do not have
two separate pieces of green – it will work, but causes the
collision detection to run much too slowly for this project.