Tutorial: BDE

By Deborah Nelson
Duke University, July 13, 2008

Under the direction of Professor Susan Rodger

As you follow the instructions below, click on an image to enlarge it.

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Loading the World

Open a new world, with the template of your choosing. Save it in a directory that you can find again. First: After you have opened the file, and set up your world, go into the "Layout" mode by clicking on the green button 'Add Objects' (toward the middle of screen)

Click 'more controls.' Click 'drop a dummy at the camera.' Rename the dummy 'originalPosition.' To leave the layout mode, click 'done' This is something you should always do when you make a world in case you need to return the camera to this view later. If you don't understand dummys,look at the camera control tutorial again.

Adding Objects

How to add objects to your scene

  1. First, drag the oceanFloor into your world
  2. In order to add the shark and lilFish2: drag each into your world instead of clicking on add instance
  3. Once you drag the object into the screen, BEFORE you drop the object (release the mouse), hold down the shift key and move your cursor forward (into the scene) until you see the yellow outline box. Then drop the object.
  4. If you still canít see your objects, drag the oceanFloor away from the camera. Move the fish up and then move your oceanFloor back

Writing the method

Create a BDE

The BDE: the conditional

The BDE: the Begin

The BDE: the During

The BDE: the End

Re-setting the BDE conditional

Play your world

  • Now when you play your world, after the shark says Gotcha, click on either the shark or the lilFish2 and move it around the screen.
  • Then, the BDE loop will happen again.
  • To move the objects up or down, hold down the shift key while you click
  • To change the direction the objects are facing, hold down the control key while you click

  • When something is true: The conditional

    Recap of BDE