1.11 Animation Details: Sub-Parts (part 1)

There's one more thing you should know before moving on to the next chapter. It's important to realize that each object has it own methods (like move and turn), but that objects also have sub-parts that can have their own methods. 

For example, let's consider slackerProm. In this chapter we made slackerProm do things like move and turn. But we can also make sub-parts of slackerProm perform actions. 

At the bottom of the page is a simple world for you to download that contains just slackerProm. Download and open this world (it's called slackerProm.a2w). 

Step 1: Click on the + button next to the object name slackerProm in the upper-left box, you can see that slackerProm has three sub-parts: upperBody, leftLeg, and rightLeg.  However, there are additional sub-parts to slackerProm's upperBody. 

Step 2: Click on the + symbol next to upperBody. You should now see leftArm, rightArm, and neck. 

Your list under slackerProm should now look like this:

If you continue to click on the + symbols next to other body parts you will to see more sub-parts. However, for this example, we are going to stop here and focus on the leftArm.

If you look under slackerProm's methods, you will notice there is no method to make slackerProm wave. But this is not a problem because, by using the methods under leftArm, we can make slackerProm raise his arm as if he is waving. We want it to look similar to the following video:

Let's look at leftArm's methods. 

                    Step 3: click on leftArm.

You should see a list like this:

There's still not a method called wave, but maybe one of these will do something that looks like a wave.  Let's look at two different methods: turn and roll -- don't try them in Alice just yet.  First, think about them. 

[Q 1.11.1] For this question, we don't expect you to know the answer for SURE.  But, based on your experiences to now, if you had to GUESS, how do you predict the turn method will behave? What about the roll method?  Will it do something else? 

First let's try the turn method.

                    Step 4: Drag the turn method into the code area. 

                    Step 5: Select right and 1/2 revolution. 

                    Step 6: STOP! Now hit Play to see what it looks like. 

Was it what you expected? Did slackerProm's arm go through his head? We did get his arm to raise like he's waving, but this seems unrealistic because in real life people's arms cannot pass through their heads.

Perhaps we should try a different method...

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Don't forget: Download the file linked below.  Launch Alice on your computer, then use File -> Open World and select the file you downloaded.

slackerProm.a2w

Save the world as LastNameFirstName-SlackerProm.a2w