Sprite Drawing (Loops)

Let's make some art! We'll see how computers can both realize and stretch our imagination.

1. Click here to load a starter project.

2. Predict: what do you think this code will do? Build and run it. What happened?

   

3. Click , and then click your script to run it again.

4. Change 100 to 50, like so: , by clicking on the 100 and typing 50. Click the script again to run it with the new input value.

5. Click in the green "Pen" palette.

6. Change the number in and run the script again... and again...

7. Change the number in the and run the script again... and again...

8. Draw a triangle with equal-length sides.

   

9. Draw a circle. If you really need a hint, you can ask a teacher or mentor.

   

10. Here are some other blocks you can experiment with! To change the pen's style, you must click the block to run it after you changed the number or color.

    

11. Let's make a more complex fractal design. Start by building a script to draw a red triangle. You can reuse your script from earlier.

    
12. Duplicate your script and change it to draw a smaller blue triangle. Below is a video showing how to duplicate a script: right-click on the "repeat" block to open the drop-down menu.
    
    Right-click on Chromebooks and Macs: press or tap the touchpad with two fingers.
    Chromebooks: you can also press Alt, then click with one finger.
    Macs: you can also press Control (not Command!), then click with one finger.
    
    
    

13. Insert the entire script for the blue triangle between the move and turn blocks of the red triangle. The video below shows how.

    

14. Predict: what will happen when you run this script? Then, run it!

15. Can you make the picture below? If you want to go farther: try embedding one more triangle, half the size of the last (green) one, in the same way.

    

Credits

Content adapted chiefly from pages 1 and 4 of BJC (June 2017) U1L2 "Sprite Drawing and Interaction" and also BJC U1L3 "Modern Art".