用WebGL代写一个直升机模拟器。
Requirement
The State Emergency Service assists people affected by natural disasters. In
this assignment, you will develop a 2D computer graphics simulation of the
operation of an SES Helicopter in a flood setting.
Australia often experiences natural disasters, particularly flood. In this
assignment scenario, a flood is rising near a town, threatening the town and
its residents. The SES helicopter (in this assignment) can rescue people who
are trapped by the flood waters, and carry them to safety. The simulation will
allow the end user to develop their skill in deciding what the helicopter
should do as the situation develops in order to most effectively protect the
town and its residents.
Task Description
This assignment is about 2D graphics in WebGL.
Write a WebGL program that provides an overhead view of an emergency services
helicopter. Show the helicopter flying over the flood scene and performing
actions as described below. The program is controlled by the mouse and
keyboard.
Also write a short report that discusses the important features of your
program, with screen shots, and provides a very brief user documentation
explaining how important features work. Use the report template provided with
this assignment on iLearn. On the front page of the template there is a table
where you must select the features that you have implemented.
Your program must meet the following specifications.
- Your program is to run in the WebGL environment embedded in Firefox developer edition as installed in the lab. In particular, your program will be tested on a computer running the same environment as in the lab. If you develop your program in your own environment, you should test it in the labs to ensure it runs in the standard environment.
- The program will display the helicopter as viewed from above, along with other features (see below).
- The helicopter may be in flight or hovering. An added feature allows the helicopter to land at an SES base.
- Short-cut keyboard actions may support additional features as defined below.
- The program must be properly commented, with authorship information including your name and student ID. Each procedure or function must have a brief comment describing the behaviour of that function. Data structures / classes must be similarly described.
- The program must follow WebGL coding conventions as presented in this unit.
- The program’s display should fill the entire canvas. Optionally, the program should adapt to changes in the canvas size.
- The program code must be your own original work. Where you use ideas from other people’s programs, you must acknowledge the author in a comment and include the URL of the source if it is on the Internet. You may use code examples from the COMP330 web site; however, it is also appropriate to acknowledge them.
- In order to receive marks for the operational features of your program, they must be obvious to the marker. This means that the marker will not be reading your source code to look for program documentation. Instead, they will check out the things that they can see on the screen, and in the first page of your report.
- Use exactly the command keys as listed in this assignment specification, so that the marker can easily operate your program.
Features
Note that the features total more than 100%. This is to allow you opportunity
to choose which features you implement. On the front page of your report, you
will select which features you want to be marked on. Note that you should not
select features with a total of more than 100% - if you do, your final mark
will be based on the first selection of features that total no more than 100%,
not the sum of marks for every feature that you implement. In other words, do
a good job of implementing a set of features that total to at most 100%,
rather than trying to implement more features but doing a poor job of each of
them.
The first two features are essential for a pass mark. All other features are
optional.
See the supplied sample screen shots for an example of what the various
features may look like. It is not intended that you copy the example screen
shots, but you are encouraged to use them to aid your understanding of the key
ideas.
Static world with buildings, a (flooded) river, and a helipad
Essential feature. This is the basic background feature required of every
program. Start with this.
Show a town from the air, with a flooded river nearby. For simplicity, the
river can be straight and the town can consist of a collection of at least 3
simple buildings. See the sample screen shots for examples of what this could
look like. Include a helipad some distance from the town.
For best marks for this section, use appropriate colours for the ground,
buildings and flooded river.
Moving the helicopter with keyboard control: turning, moving forward
Essential feature. This feature provides a basic helicopter. The helicopter
can be a simple polygon that roughly resembles a helicopter viewed from above.
The helicopter should appear to be about 50-150 pixels long - detail needs to
be visible but the helicopter should be able to move on the screen a
significant distance relative to its length. The helicopter does not need to
be in scale relative to the features on the ground.
Keyboard commands are used to control the helicopter - see the keyboard
command table below. The speed of rotation of the helicopter, and the speed of
movement, should be chosen so that it is possible to move the helicopter
across the screen in about 4-8 seconds, and it should be possible to rotate
the helicopter by 180 degrees in about 2-4 seconds.
Helicopter with spinning tandem rotors
Enhance the helicopter by showing spinning rotors on top of it. Google
“helicopter with tandem rotors” or see
https://en.wikipedia.org/wiki/Tandem_rotors
. You will find that such
helicopters have one rotor at the front and another at the rear. The rear
rotor spins in the opposite direction to the front rotor.
Whenever your helicopter is in flight, or hovering, the rotors should spin
relative to the body of the helicopter. Choose a rotation speed that allows
the user to clearly see the rotation happening - say to 1 rotation per second.
Rescuing people
People sometimes need to be rescued. At random times, a person may appear near
one of the buildings desperately needing to be rescued. This is more likely to
happen if a building is close to the floodwaters. Since rescuing people is the
main simulation activity, ensure that people needing to be rescued appear at a
suitable rate to make the simulation interesting, and perhaps challenging at
times, but not impossible.
Rescue consists of picking people up and taking them to the SES base. The base
is the helipad together with a building next to it.
The helicopter can hover over the people and pick them up, carry them back to
the base and safety. When the helicopter is over the person, press the command
key listed below to pick up the person. Fly to the base and land there, using
the command key listed below, to take them to safety. After landing, the
people leave the helicopter.
To make it simple to determine whether the helicopter is over a person, you
can just compare the centre point of the helicopter with the centre point of
the person. If the distance between them is less than about 1.5 times the
width of the helicopter, then the helicopter can pick up the person. Use a
similar rule to decide whether the helicopter is over the helipad so that it
can be commanded to land. You can adjust the radius to make the game play work
better.
When the helicopter picks up a person, show the person on the helicopter until
the helicopter lands. After landing, they leave the helicopter and enter the
SES base building, so they are no longer visible on the screen. You do not
need to animate people moving from the helicopter to the building, although
you can if you wish.
To instruct the helicopter to take off again from the base, press the command
key listed below or instruct it to fly to a destination location.
Resizing the canvas, maintaining aspect ratio
If the user resizes the drawing canvas, your program will ensure that the
resulting display maintains the correct world aspect ratio. This means that
you may need to display more or less of the world. Ensure that your solution
maintains a sensible display even if the canvas is resized many times.
Control helicopter with the mouse
Your program responds to a mouse click on a screen location by sending the
helicopter to that location. The helicopter must turn towards the target
position, and fly towards it. When it arrives, it must hover at the location,
awaiting further commands.
Animate the helicopter to respond to the mouse click by turning towards the
destination position and then flying towards it. To provide the user with
reasonable control, it should take somewhere between 4 and 8 seconds for the
helicopter to move from one side of the screen to the other.
Simple animation of the helicopter will appear that the helicopter can turn on
the spot when it is stationary but the helicopter should not spin too quickly-
it should take the helicopter somewhere between 2 and 4 seconds to complete a
180 degree rotation.
To instruct the helicopter to move, the operator clicks on the destination
position for the helicopter. The helicopter then starts to execute the
instruction, by turning to the direction of travel and then flying forward at
a steady pace until it reaches the marked point where it hovers.
For added realism, the helicopter may be observed to accelerate and decelerate
rather than instantaneously changing its speed of motion. It may also be
observed to turn and fly forward at the same time, traveling on an initially
curved path towards the destination.
Camera mounted on the helicopter
The program normally shows the view from above the entire scene. Provide a
short-cut command as listed below to switch to show the view from the
helicopter. The same command can switch back to show the entire scene - it
switches between the two modes.
The helicopter itself will not appear in the view from the helicopter. To make
the view from the helicopter more interesting, show only the area immediately
surrounding the helicopter, with all features on the ground enlarged by a
factor of between 2 and 3, as though the camera on the helicopter had a
telephoto lens. Also, when the helicopter lands, zoom in on the base and zoom
out again when it takes off.
Note that, when the helicopter turns, the ground scene will appear to rotate
in the opposite direction, since the camera turns with the helicopter.
Similarly, when the helicopter flies forward, the ground will appear to move
in the opposite direction because the camera is moving with the helicopter.
You should assume that the camera on board the helicopter is aligned so that
“up” in the image corresponds to the longitudinal axis of the helicopter -
i.e. to the direction “forward” on the helicopter.
Minimap
Use a viewport to draw a minimap of the entire world and the helicopter
location in a corner of the screen. Use a separate (larger) viewport for the
main camera view.
Curved rivers
Draw the river and a branch, or two rivers, as extruded curved 2D shapes.
Rain
Use a particle system of points to draw rain falling across the scene.
Raindrop locations should be randomised and the points should get smaller as
they drop to the ground and then disappear.
Heads up display
Provide a status display overlaid on the camera view that shows the ground
speed of the helicopter. When the helicopter is hovering or landed, it should
show 0 speed, but when it is flying forward it should show the speed of
motion. Draw a standard “needle” type of speedo, and you don’t have to show
any numbers, just the speedo arcs, speed tick marks and the needle.
Keyboard Commands
To avoid any confusion, here is a table of all keyboard commands that you may
use in this assignment. You must use the exact keyboard commands listed here,
to simplify marking.
Where more than one key is listed, your program should respond to every
alternative. For example, to pick up a person, the user may press lower case
‘p’ or upper case ‘P’ and both should work.
| Keyboard command | Action |
|---|---|
| Left arrow | Helicopter rotates anticlockwise in the world as viewed from |
| above. Hold for continuous rotation. | |
| Right arrrow | Helicopter rotates clockwise. Hold for continuous rotation. |
| Up arrow | Helicopter moves forward a fixed distance. Hold to fly forward at |
| a fixed speed. | |
| ‘p’ or ‘P’ | Pick up a person |
| ‘l’ or ‘L’ | Land the helicopter at the base |
| ‘t’ or ‘T’ | Take off from the base. The helicopter rises and hovers. |
| ‘c’ or ‘C’ | Switch camera views - normal or helicopter mounted camera |
Marking
The features that you identify in your report will be marked against the
requirements listed above. Some marks will reflect creativity and user
experience, but the majority of marks will be for implementation showing that
you have understood and applied the relevant WebGL features.
If your feature set exceeds 100%, the marker will not mark excess features.
Select the features on the front page of your report that you want to be
marked. Do not select features totalling more than 100%, as the marker will
ignore excess features.
Submission
Submit your program as a WebGL project that can be run in the lab’s Firefox
developer edition browser environment. Be sure that your program does not
crash in testing - markers cannot correct programming bugs that you may
introduce at the last minute so be sure to test your final submission
thoroughly.
- Markers cannot test your program in any other environment. You must ensure that it works in the lab environment.
- You are encouraged to use a source code revision management system (such as Git) to manage your project.
- Make small changes and test them thoroughly before moving on to other features.
- Test the interactions between features.
- Make it clear to the marker what your program can do, and how to use it. In particular, the summary table in your report will be used by the marker to explore your program’s capabilities.
Details of the submission method will be provided as an update to this
assignment specification - watch this space.
