CS 151: Project 6

Project 6: Animated Scene

Main course page

The purpose of this project is to give you experience with both top-down design and efficient coding practices that take advantage of things with similar structures.


Tasks

The result of this assignment will be similar to project 3. You'll create a scene that is a collection of complex objects. The complex objects will all be collections of Zelle graphics primitives and have the same organization as the steam plant you created in lab. Each complex object will have a function that initializes it and any complex object that changes will have a function that animates it.

The big difference from project 3 is that your scene can be animated, with objects moving or changing colors.

  1. Think about a scene you want to create. Design the scene on paper as a collection of complex objects like buildings, streets, stoplights, and cars. Keep it simple. Come up with at least 2 complex objects of your own that you want to create for your scene. At least one of them will need to animate in some way. Animation can involve motion or changing color.

    For each of the complex objects, create a new init function in complex_shape.py. For the steam plant we created steam_init. Follow the same convention for your other complex objects. For a stoplight, for example, create stoplight_init.

    The init function should always take an x, y, and scale, which you should use just as in project 3 so that the object can be placed anywhere at any scale. The init function should return a list of the primitive objects that make up the complex object, just like we did with the steam_init function.

    If your complex object should animate, create an animation function for the complex object. Use the same naming scheme, putting a _animate after the object's name. We created steam_animation_frame for the steam plant. You would create stoplight_animate for a stoplight.

    You need to animate at least one of your new complex objects, even if it means just changing colors. The animate function should take in at least three parameters: the list of objects in the shape, the frame number, and the window, just like our steam_animation_frame function. You can give the animate function any number of other parameters necessary for it to work properly. For example, you may want to include the scale used to create the image, so that movement can scale with the size of the shape.

    For each complex object you create, make a test function in complex_shape.py, just like we did with test_steam. The test function should create a window, create multiple versions of the complex object, and then wait for a mouse click to quit. If your animate function does something interesting, test that out as well.

    Include a small picture for each complex object in your writeup.

  2. Make a file scene.py and import your complex_shape package, the graphics package, and the time package. This file should have at least a main function (you can create other functions as you see fit to organize the code).

    The main function should initialize the complex objects in the scene and draw them. It should then execute a loop and animate the complex objects that change (i.e. the ones with animate functions). It will be similar to the lab6test.py main function from lab. Note that in lab6test.py, we put the steam plant complex objects in a list. You may want to use lists if you have multiple copies of the same object. But if you have one copy of each type of object, then you may want one variable for each object. The important thing is to make your code both succinct and readable.

    Do something creative within this framework.

    Include several pictures of your scene animating in your writeup.

  3. Alternatively, you can create an animated gif to post (this is preferred but not required).

    Note, you can use the time.sleep() function to make your animation slow enough that you can do a screen capture on each frame. If you do that, then you can create an animated gif using the following command in Terminal inside the directory where your screen shots are saved.

    convert -delay 60 *.png myanimation.gif

    The file myanimation.gif will be an animated gif that you can put on a web page.

    Alternatively, you can also create movies of your screen using Quicktime.


Extensions


Writeup and Hand-in

Turn in your code by putting it into your private handin directory on the Courses server. All files should be organized in a folder titled "Project6" and you should include only those files necessary to run the program. We will grade all files turned in, so please do not turn in old, non-working, versions of files.

Make a new wiki page for your assignment. Put the label cs151s15project6 in the label field on the bottom of the page. But give the page a meaningful title (e.g. Stephanie's project 6).

Your writeup should follow the outline below.


Making a GIF from PS files

In order to make a GIF from PS files created using the saveFrame function, you need to first convert the PS files to PNGs in a way that removes the alpha channel and sets the background color to white. You can do that using the following python file.

ps2png.py

If you have a set of .ps files in your directory, you can run it using the following.

python ps2png.py *.ps

This will create a whole bunch of png files, one for each ps file. Then you can make your animated gif using the command:

convert *.png -delay 30 myanimation.gif

Note that if your files are numbered in such a way that typing ls does not list them in order, then you will need to re-number them. You can do that by creating filenames using the following code.

filename = "frame%03d.ps" % (frame_num)