How to Create a Falling Snowflakes Character in MicroWorld EX

By Camille McCue

Follow these steps in MicroWorld EX to create a snowflake character, add the fall procedure (which you create later in this project) to it, and make multiple copies of the snowflake.

How to create snowflakes in MicroWorld EX

  1. From the toolbar, click the Create a Turtle button. Move to the snow area of your workspace and click to hatch a turtle.


  2. Now, you need to paint a shape for the snowflake. On the project Shapes tab, double-click a shape spot.

    The Shape Editor opens.

  3. Use the drawing tools in the Shape Editor to draw a snowflake:

    • Use gray, not white, to draw the snowflake so it can be seen against the white of the snowy ground.

    • Move the opacity slider to 70% so that the snowflake is slightly transparent.

    The Shape Editor closes, and the snowflake shape appears in a spot on the project Shapes tab.

  4. Make copies of the snowflake. Right-click (Windows) or Ctrl-click (Mac) the snowflake shape and select Copy. Move to the next empty shape spot and right-click (Windows) or Ctrl-click (Mac) and choose Paste. Paste the snowflake on each of the next two shape spots.


    In the example, you should now have four identical snowflake shapes on the project Shapes tab.

  5. Now, you create animated snowflake shapes. Double-click the second snowflake shape.

    The Shape Editor opens.

  6. Click the Angle drop-down button to change the angle to 90 degrees and then click the Rotate Clockwise button.


    The shape rotates.

  7. Click OK.

    The Shape Editor closes and the rotated snowflake shape appears in a spot on the project Shapes tab.

  8. Repeat this process for the third snowflake, rotating it clockwise 180 degrees. Repeat again for the fourth snowflake, rotating it clockwise 270 degrees.


    The animated sequence of snowflakes for the example.

  9. Next, you add the animated snowflakes to the turtle. Click the first snowflake shape, and then hold down the Shift key and click the last snowflake shape.


    All the snowflake shapes are selected

  10. Move into the workspace and click the turtle.

    The turtle now wears the animated sequence of snowflakes.

    When the snowflake is not moving, you see only one snowflake in the workspace. But you can check that all the snowflake shapes are in the turtle backpack. Right-click (Windows) or Ctrl-click (Mac) the turtle and select Open Backpack. On the State tab, the Shape field shows the shape numbers of four shapes — these are the four snowflakes


    The snowflake shapes don’t have names because you left them unnamed in the Shape Editor. Because these shapes will not be referenced by name, there is no need to name them.

  11. Next, you need to add a fall procedure to the turtle. With the backpack still open, switch to the Rules tab. Type fall in the OnClick field and set it to Forever


    The fall procedure, which you write later in the project, makes the snowflakes fall to the ground in a gentle, irregular pattern.

  12. Close the turtle backpack by clicking its X button.

  13. Make a copy of your animated snowflake turtle as follows. Right-click (Windows) or Ctrl-click (Mac) the turtle and select Copy from the pop-up menu. Click the background and select Paste.

    A copy of your animated snowflake turtle appears.

  14. Click Paste again to drop another animated snowflake turtle on the background. Repeat this step 8 to 12 times to add multiple copies.

  15. Click and drag the animated snowflake turtles, one at a time, into the sky area of the workspace.


How to write a MicroWorld EX Fall Procedure

Your scene will use a fall procedure to make the snowflakes fall with a gentle, irregular pattern to the ground.

In the Procedures pane, write a fall procedure as follows:

to fall
seth 180
rt random 45
glide 100 0.2
lt random 45
glide 100 0.2

The fall procedure is executed forever from each snowflake turtle’s OnClick field when the turtle is clicked.

The fall procedure sets the snowflake turtle heading (seth) to south (180), and then turns the heading slightly to the right (rt) by a random quantity (random 45). The turtle then glides 100 pixels at a slow pace of 0.2 (glide 100 0.2). Finally, the turtle performs a slight left turn (lt) by a random quantity (random 45), followed by the same glide command it executed previously (glide 100 0.2).