How to paint camouflage


You can find camouflage everywhere in nature, it is the behavior of many animals to freeze in motion when in danger. This project aims to help the students to find a comprehensible explanation for why animals "freeze" when they are threatened. Can youto introducehow do animals behave in danger? To understand this, you become an animal and its environment to inventso that it can camouflage itself, describe its behavior, and observe it. Get away from this projectto inspire, to design puzzles or moving pictures yourself.

In this project we use:

Halo, Name, Paint Tool, Write Scripts, Increase By


(Original idea by Alan Kay)

First, open a new project. you can do that by launching Etoys and clicking on the purple cloud that says "New Project". Now the entire Etoys world is at your disposal. Let's start by painting some grass and then a grasshopper, both in the same shade of green.

How to paint

To paint objects in Etoys, there is a painting tool in the navigation bar at the top of your window. Click on the symbol shown above and you will receive a new sheet of paper and the tools to paint on.

Every time you click on the symbol, you get a new sheet of paper and a new drawing is started. For our example here you need to make two drawings, one for the grasshopper and one for the grass. Make sure to quit the painting tool every time you finish a drawing.

You can find out more about the individual functions of the painting tool in the Etoys brief instructions under "Painting". You can get an overview in the chapter "Finding Help" in this book.

The drawings you have painted are actually objects that you can touch and move around the screen. They are called "drawing" until you give them another name.

How to display the halo and name a drawing

To give your drawing a different name, you'll need to display the halo for that object. You can do this by right-clicking on the object (cmd-click on Mac). You will now see a number of colored circles around the object and the name of the object at the bottom. Click on "Drawing" and type in the name you want to give.

Now move the grasshopper into the grass. You can immediately see how its green color can help it escape from birds and other enemies that want to eat it.

Now let's write a very simple script for the grasshopper to move sideways in a right-left direction. (the correct designation for the direction is x). The Etoys world is a two-dimensional coordinate system in which x is the value for the horizontal position of an object (it starts with 0 on the left edge).

How to write a script

Writing a script in Etoys means putting together a script from prefabricated tiles of the objects. You can find the tiles for each object in its viewer. You can open the viewer to an object by clicking the blue icon with the eye in the halo. The viewer for the grasshopper looks like this:

Under the heading "Simple" (for category Simple) you will see the tile "Grasshopper x" in the upper part of the viewer.

Drag the tile into the Etoys world by grabbing the white arrow. The moment you let go of the tile, a script editor is created around the tile. If that doesn't happen, you have to try again, making sure that you really touch the tile by the white arrow.

Now you can change the command to take the action you want. Click on the little black arrow in the command tile to get a menu with the different available operations. Select "increase by" to move the grasshopper from left to right. You can change the value for "increase by" by clicking on the number and typing in a different one. For more help, see Etoys Quick Start Guides - Tiles - X and Y Tiles.

Now start the script by clicking on the clock at the top of the script editor. The script will repeat the command over and over until you click the clock again to stop it.

Suddenly you can see where the grasshopper is and so can most other animals. This gives you a little insight into why animals' eyesight is almost always better at recognizing movement than at seeing small details - and also why animals prefer not to move when they are threatened.

When you're done, you will definitely want to save your work to use again later or to show your friends and family. You can also make different versions with different ideas.

How to save and load

The button you see above is used to publish or save. Find it in the navigation bar and click on it. A dialog box will open. This asks you to enter a name for the project (so that you can find it more easily later). If you want, you can also enter your name in the field for the author, a description and other information. After clicking "Ok", another dialog window opens in which you can select the target for your project. The default destination is the Etoys directory on your computer. It is highly recommended that you also save all your projects here, because this is also the directory that is displayed by default when you want to load a project.

To open a project from your directory, you have to click on the "Load" button in the navigation bar. All projects that you have previously saved in your Etoys directory are displayed. Select the one you want to open and click "Ok". The project will now open in Etoys. To go back to the previous project, you can use the white arrows in the navigation bar.

You can find more information on loading and saving in the Etoys Quick Start Guide - Tools - Save and Load.

Inspiration for further projects

The project used in this chapter can be found here:

If a living thing like the grasshopper lived in a desert, what color do you think it would be? Can you create a project for it?

You can use the things you learned in this chapter to create many wonderful drawings with moving objects.

Or you can do a puzzle like you can see here in the projects of Avigail Snir's first graders (and older students too):