1
COM3503 3D Computer Graphics: Assignment (50%)
Dr Steve Maddock
Deadline: 3pm, Tuesday 7 December
1. Introduction
The assignment will involve using modern OpenGL to render a scene. Scene graphs are required in the modelling
process and animation controls are required for hierarchical models.
2. The task
Figure 1 shows a room scene containing three objects, a robot and a window looking out onto a view. The whole scene
can be modelled using transformed planes, cubes and spheres. The scene shows five poses of a robot that has entered
a museum exhibition room. Pose 1 is on entering the room. Pose 2 is viewing a large mobile phone displayed on a
plinth. Pose 3 is viewing a spotlight on the floor as it swings side to side on a stand. Pose 4 is viewing a large egg on a
stand. Pose 5 is looking out of the window.

Figure 1. The scene
1
3
5
Floor and two walls need
texturing, e.g. wood, paint
pattern, etc
A window
4
2
3. Requirements
You must satisfy all the following requirements.
3.1 The room
• Only two walls and a floor for the room should be
modelled.
• The walls and floor should be texture mapped to look
like a room in a museum. For example, the floor could
be made of wood. The walls should have a paint
pattern on them.
3.2 The window
• An outside scene can be seen through the window,
for example, this might be a garden scene or a city
scene. You could use a picture out of a window in
your own accommodation or you could invent a
picture.
• Consider how you might do the scene outside:
o Should it be a texture map pasted onto the wall
to look like a fake window and a scene (Figure 2a).
o Or should there be a hole in the wall and a texture
map pasted onto another surface that is a certain
distance outside the window? This will mean
making the wall from a set of pieces, e.g. eight
abutting pieces with the window as a middle
area. Figure 2b illustrates this.
o Another option might be a skybox outside the
whole room.
• Depending on the approach you choose:
o 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?)
o The scene outside the window should not be the
same at different times in the day (e.g. different
times of the day and night). How might you
achieve this with texturing effects?
• The quality of what you produce for this part of the
scene will be part of the marking.
3.3 The robot
• This is a hierarchical model made of different shaped
spheres.
o 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 robot should have a head, a neck, a body and a
‘foot’ (a sphere that can roll). You must design a head
that has a minimum of 4 pieces. Figure 3 gives some
possible designs. The design of the head is your
chance to show a bit of creativity.
• It should be possible for the whole robot to rotate
about the foot so the robot can lean forwards or
backwards or to one side or the other as part of
different poses.
• It should be possible for the head to rotate about the
neck so the robot can lean its head forwards or
backwards or to one side or the other as part of
different poses.
• It should be possible for the features of the head to
move around the head to help make the poses
distinctive. Depending on your head model, this
might be eyes move to look forwards or hat tilts to
one side or nose grows or glasses or ears or hairpiece
change orientation as part of different poses.
• The robot is required to make 5 different, distinctive
poses, one at each location indicated in Figure 1.
3.4 The mobile phone
• This can be modelled using two cubes, one for the
phone and one for the stand.
• The mobile phone cube should be texture mapped so
that it looks like a mobile phone with a typical screen
display.
3.5 The swinging spotlight
• This can be modelled using cubes and a sphere for the
spotlight bulb.
• The spotlight mechanism should swing from side to
side so that the spotlight is visible on the floor of the
room.
3.6 The large egg
• 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.
Figure 3. Some possible robot head designs.
Figure 2. (a) Pasting a texture on the wall; (b) a
hole in the wall to see the texture pasted on a
plane at a certain distance away.
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3.7 General illumination
• The scene should be illuminated with at least two
general world lights which can be positioned
anywhere in the world (perhaps with one in the
general direction of the sun).
• 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 swinging spotlight will be much clearer on the
floor.
• 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 one of the
exercise sheets – 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 one on the exercise sheet. If you
change the key mappings it will make it difficult to
mark. It doesn’t matter that the camera can see
outside the room.
• It should be possible to turn each of the general
illumination lights on and off (or dim, i.e. reduce the
intensity) from the interface.
• It should be possible to turn the spotlight on and off.
• There should be buttons to show the robot in each of
its poses, e.g. pressing a button labelled ‘Pose 3’
would move the robot to pose 3. This is an immediate
movement to the new pose – the robot disappears in
one position and reappears in the new position.
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.
• The robot should animate between the poses rather
than immediately move 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 but not done the robot poses. 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
on exercise sheets. However, use your comments to
state which bits you used or which bits are new.
• The body of the Blackboard submission message
should state that the work you have handed in is your
own.
• The name of the main class in your program should
be Museum. That way it is easy for me to run the
program. (Last year, I wasted time for some handins
trying to work out which was the main class to run.)
It would be useful to include a 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 code
will be run and exercised thoroughly.
Marks will be available for:
• The quality of the programming (20%)
• Satisfying the requirements (80%)
In assessing the quality of your program code, four
aspects will be considered:
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• (5 marks) General style: layout; neat, organised code;
comments; use of constants and variables; methods
not over long;
• (5 marks) Program and data structures for the
models: use of separate methods and classes, e.g.
separate classes for things like the robot; (The online
tutorial does not make use of classes for the more
complex examples, partly on purpose. I want you to
show that you can structure things appropriately. You
must consider the use of classes for the assignment –
this demonstrates your programming ability.)
• (5 marks) Neat and tidy coding for dealing with
transformations in the scene; How will you organise
the construction and use of the scene graphs? It
shouldn’t all be in one method!!
• (5 marks) Animation/posing control: how tidy and
flexible is the coding?
In considering the requirements, four aspects will be
considered (including the quality of the work):
• (20 marks) Modelling the scene: the robot must be a
hierarchical model. (Consider drawing scene graphs
for the scene before starting to program.)
• (20 marks) Texturing: Use of texture mapping in the
scene, e.g. basic texture mapping, use of diffuse and
specular textures, seams between textures and any
extra texturing effects such as the changing window
view.
• (15 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.
• (25 marks) Robot pose control (10) and animation
(15). 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
websites. 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.

Links to handbooks

UG:
https://sites.google.com/sheffield.ac.uk/comughandbo
ok/general-information/assessment

PGT:
https://sites.google.com/sheffield.ac.uk/compgtstuden
thandbook/menu/assessment



















































































































































































address here> */
• You can make use of all the code that I have given you
on exercise sheets. However, use your comments to
state which bits you used or which bits are new.
• The body of the Blackboard submission message
should state that the work you have handed in is your
own.
• The name of the main class in your program should
be Museum. That way it is easy for me to run the
program. (Last year, I wasted time for some handins
trying to work out which was the main class to run.)
It would be useful to include a 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 code
will be run and exercised thoroughly.
Marks will be available for:
• The quality of the programming (20%)
• Satisfying the requirements (80%)
In assessing the quality of your program code, four
aspects will be considered:
4
• (5 marks) General style: layout; neat, organised code;
comments; use of constants and variables; methods
not over long;
• (5 marks) Program and data structures for the
models: use of separate methods and classes, e.g.
separate classes for things like the robot; (The online
tutorial does not make use of classes for the more
complex examples, partly on purpose. I want you to
show that you can structure things appropriately. You
must consider the use of classes for the assignment –
this demonstrates your programming ability.)
• (5 marks) Neat and tidy coding for dealing with
transformations in the scene; How will you organise
the construction and use of the scene graphs? It
shouldn’t all be in one method!!
• (5 marks) Animation/posing control: how tidy and
flexible is the coding?
In considering the requirements, four aspects will be
considered (including the quality of the work):
• (20 marks) Modelling the scene: the robot must be a
hierarchical model. (Consider drawing scene graphs
for the scene before starting to program.)
• (20 marks) Texturing: Use of texture mapping in the
scene, e.g. basic texture mapping, use of diffuse and
specular textures, seams between textures and any
extra texturing effects such as the changing window
view.
• (15 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.
• (25 marks) Robot pose control (10) and animation
(15). 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
websites. 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.

Links to handbooks

UG:
https://sites.google.com/sheffield.ac.uk/comughandbo
ok/general-information/assessment

PGT:
https://sites.google.com/sheffield.ac.uk/compgtstuden
thandbook/menu/assessment


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