COM6503: 3D Computer Graphics: Assignment
Dr Steve Maddock
Deadline: 3pm, Wednesday 7 December
1. Introduction
The assignment involves using modern OpenGL to render a scene. Scene graphs are required in the modelling
process and animation controls are required for hierarchical models.
Learning outcomes: After completing this assignment, you will be able to:
Use data structures and mathematics in representing and manipulating 3D objects
Produce interactive software that makes use of a graphics API
Figure 1. The scene
A window as big as the wall.
There is a cloudy sky outside.
The view is changing over time.
Should this be a texture on a
polygon at a certain distance or
should it be a skybox?
Egg-like object on a rectangular base on
a table. The egg-like object has both matt
and shiny parts. The egg occasionally
rotates and jumps.
Anglepoise lamps can adopt different
poses to point their heads in different
directions. The square LED bulb in a
lamp’s head functions like a spotlight in
the scene. I’ve shown one in yellow to
highlight it.
Desk, floor and walls
need texturing, e.g.
wood, wallpaper, etc
Each anglepoise lamp is a slightly
different size and has some
different pieces attached to it.
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2. The scene to create
A company is creating an advert for a range of new
angle-poise lamps that look like alien animals. Your task
is to create a scene for this.
Figure 1 shows a room scene containing a table, an egg-
like object, two anglepoise lamps and a window looking
out onto a view. The whole scene can be modelled using
transformed planes, cubes and spheres.
The lamps are inspecting the egg. The base of each lamp
is fixed, but each lamp can each articulate its joints so
its head points in different directions. The egg-like
object occasionally jumps and twists (rotates), as
though there is something inside trying to get out.
3. Requirements
You must satisfy all the following requirements.
3.1 The room
Three walls and a floor for the room should be
modelled.
The walls and floor should be texture mapped to look
like a meeting room. For example, the floor could be
made of wood. The walls should have a texture
pattern on them.
3.2 The window
The back wall in the room is a large window.
An outside scene can be seen through the window,
for example, this might be a garden scene or a city
scene or some advertising text (e.g. “new alien animal
anglepoise lamps”) that scrolls past the window.
Consider how you might do this:
o Should the scene be a texture map pasted onto
the wall to look like a fake window and a scene?
o Or should there be no wall and instead a texture
map pasted onto another surface that is a certain
distance outside the window (as illustrated in
Figure 1)? Should there be a small frame for the
window?
o Or should a skybox be used that is outside the
whole room?
Depending on the approach you choose, how does it
look when the camera moves position in the room
when looking out of the window? (Is it possible to
stand in the room and not see the scene outside
through the window?)
The scene outside the window should change whilst
the program is running, e.g. the clouds might move.
The quality of what you produce for this part of the
scene will be part of the marking.
3.4 An anglepoise lamp
The hierarchical model of a basic angle-poise lamp
should be made up of five parts: a base, a lower arm,
an upper arm, and a head, which contains a
protruding lightbulb (a nose) in the shape of a cube
(the details of the lighting technology used are not
important). There are also some additional pieces –
see below.
The lamp base is in a fixed position in the room. (If
you wish, you can animate the base to move a little
bit, e.g. slide around, but this is not required for the
assignment.)
Three parts of the lamp can articulate as illustrated in
Figure 2. The lower arm can rotate about the
connection point with the base in two directions (in a
circular way, and the lower arm can also articulate
with respect to the base like an elbow joint), the
upper arm can rotate about the lower arm (again, like
an elbow joint) and the head can rotate about the
upper arm (again like an elbow joint).
The lightbulb shines in the same direction that the
head is pointing in.
There should be some decorative pieces that make
the lamp look unusual or like an animal (see Figure 2).
Do not just copy the decorative pieces used in Figure
2; invent your own pieces. For example, you might
make the ears more interesting, or add pointy hair, or
horns, or a larger nose, or a different tail.
Use simple objects for the individual parts, i.e. scaled
spheres or cubes. For example, in Figure 2, the head
is made from a combination of a cube for the lamp
head and a cube for the bulb, with some other cubes
and spheres for the decorations. Cubes and spheres
are the only pieces needed to model the lamp. The
hierarchy and associated transformations are more
important than the quality of the pieces in the
hierarchy. I want you to demonstrate that you
understand transformations and a scene graph
hierarchy.
The pieces of the lamp must be texture-mapped. For
example, you might decide to make the pieces spotty
Figure 2. A model of an angle-poise lamp
that looks like a strange alien animal.
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to look like a particular animal. As another idea, you
might texture map a picture of feet onto the base.
The head of the lamp must include an object (e.g. a
nose bulb), modelled as a cube or sphere, which
mimics the effects of a spotlight. The object gives the
position of the spotlight and the orientation of the
head gives the direction the spotlight is pointing in.
The spotlight will thus illuminate the scene in the
direction the lamp head is pointing in. (The dotted
lines in Figure 2 are just to illustrate the direction the
spotlight is pointing in.) There must be an option in
the interface to turn the spotlight (and look of
associated object) on and off. (You are responsible for
working out how to implement a spotlight effect –
read the relevant section in Joey’s online tutorial.)
3.6 The large egg-like object
The egg-like object can be made using a cube for the
base and a sphere for the egg-like part.
The egg should be texture mapped with matt and
shiny parts. (Hint: diffuse and specular maps.) Figure
1 shows a pattern with shiny spots, but a different
pattern would also suffice.
3.7 General illumination
The scene should be illuminated with at least two
general world lights which can be positioned
anywhere in the world.
These general world lights will illuminate all parts of
the scene and help visualise the scene during
development and testing.
When you switch off the general light(s), the effects
of the spotlights on the anglepoise lamps will be
much clearer.
You do NOT have to do shadows. Do not worry about
shadow effects.
3.8 User interface
A user-controlled camera should be positioned in the
scene. Use the camera that was given in the tutorial
material – the mouse can be used to change the
direction the camera is pointing in, and the keys can
be used to move about. Do not change the key
mappings from the ones in the tutorial. If you change
the key mappings, it will make it difficult to mark. It
doesn’t matter that the camera can move and see
outside the room.
It should be possible to turn each of the general lights
on and off (or dim, i.e. reduce the intensity) from the
interface.
It should be possible to turn each spotlight (lamp
bulb) on and off.
There should be buttons to move each anglepoise
lamp into three different poses, so six buttons to do
this (three for each lamp). One pose for each lamp is
its default, looking at the egg. The other two poses
for a lamp could be anything, e.g. looking at the other
lamp or looking under the table or looking towards
the window. However, these poses should be
obviously visually different for each lamp.
3.9 Animation
This requirement is advanced and you may decide not
to do this part, although you would not be able to get
full marks.
Each lamp should smoothly animate between its
poses rather than immediately transition from one
pose to another pose.
It is perfectly acceptable to animate the Euler angles
to achieve movement of the hierarchy. Do not
consider using quaternions, as this is beyond the
requirements for this assignment.
4. Deliverables
You should submit a zip file containing a copy of your
program code (and any other necessary resources,
e.g. image files for the textures and a readme.txt file
that describes everything) via Blackboard – this can
be done via the link to the assignment handout.
You should submit whatever you have done, even if
you have not completed all the requirements – for
example, you might have produced a model of the
room and a single lamp, but not done two lamps or
the different lamp poses or animation. If you submit
nothing, you cannot receive any marks.
The program MUST compile and run from the
command window on a Windows PC or the terminal
window on a Mac. You should assume that the jogl
environment (and paths) has already been set up, so
you do not have to include this as part of what you
hand in. I won’t install ‘YetAnotherIDE’ to make your
program work; I want to run the program (and, if
necessary, check the compilation) from a command
(or terminal) window.
You must include appropriate comments in your
program to identify that you wrote the code, e.g.
/* I declare that this code is my own work */
/* Author address here> */
You can make use of all the code that I have given you
in the tutorial material. However, use your comments
to state which bits are new.
The body of the Blackboard submission message
should state that the work you have handed in is your
own (except for the bits I supplied).
The name of the main class in your program should
be Hatch. That way it is easy for me to run the
program. (In previous years, I have wasted time for
some handins trying to work out which was the main
class to run.) It would be useful to include a
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batch/script file to automatically compile and/or run
the program.
Optional: You might like to make a short video of your
animation. If you do so, DO NOT include this in the
handin as it will be too big for Blackboard to handle –
we tried using Blackboard for this in the past and it
crashed the system!! Instead, put the animation on
youtube or your personal website and give the URL of
the animation in a readme.txt file. Indeed, if you are
thinking of a career in the graphics industry, then you
should be adding such animation pieces to your
personal website (your digital portfolio) to show off
what you are capable of.
5. Marking
I will check that the program meets the requirements
listed above. To make sure you get some marks, the
program must compile and do some part of the work
requested even if it is not complete. Your program will
be run and exercised thoroughly.
Marks will be available for:
The quality of the programming (10%)
Satisfying the requirements (90%)
In assessing the quality of your program code, the
following aspects will be considered: general neatness
and organisation; use of data structures, classes and
functions; organised scene graphs; animation flexibility.
In considering the requirements, four aspects will be
considered (including the quality of the work):
(24 marks) Modelling the scene: each anglepoise
lamp must be a hierarchical model. (Consider drawing
scene graphs before starting to program.)
(24 marks) Texturing: Use of texture mapping in the
scene, e.g. basic texture mapping, use of diffuse and
specular textures, extra texturing effects such as the
changing window view.
(18 marks) Lighting and interface controls: lights
should behave correctly such that their effect is seen
on the scene. Necessary interface controls, as
described in the above specification, should also be
included.
(24 marks) Lamp pose control and animation. Are all
the poses produced and distinct? Is the animation
plausible and smooth?
6. Unfair means
The Department’s student handbooks (UG and PGT,
see below) give detailed information on the topic of
unfair means and what happens if unfair means is
used.
Some students in previous years have placed
solutions of their assignments on their personal
world-readable websites – where possible, they have
been asked to take these down. Be careful you are
not attracted to these, as using any of their code
would be regarded as use of unfair means – this has
happened in previous years and students have failed
the module as a result of doing this.
7. Late submission
Standard Department rules will be applied if the work
is handed in late – see UG and PGT handbooks below.