159.235 Assignment 3 - A 3D Graphics Scene
This assignment covers the concepts of coordinate transformations (in homogeneous coordinates), ray tracing, illumination, shading, and texture mapping. The necessary theory is
discussed in the lectures together with programming tips.
Getting started
The Stream site provides some startup .java code together with some images you can use
as texture maps. You can find this under the “Assignment 3” section.
• Bring up IntelliJ and create a new project - call it Assignment3 (or whatever). Create
a new package called nz.ac.massey.a3.
• Copy all the .java files from Stream in to the package folder in IntelliJ.
• Copy the images into the top level folder of your project
• Run Main.java from IntelliJ. You should see a JPanel/JFrame with a blue square at
the centre. This is the view of the graphics scene comprising a single plane surface
from the point-of-view of an imaginary camera placed on the z-axis and looking down.
Try changing the camera and target positions and see what happens.
• Have a look at the code and read the comments and figure out what is going on. Note
that the planar surface is rendered by the ray tracing method.
Going further
The next steps are to try and render other shapes, and implement shading, colouring, and
texture mapping.
• Complete the implementation of the placeModel() method in the Placement class. This
will set up the transformations to/from local to world space. Once this method is set
up, try changing the position, orientation, and size of the unit plane surface.
• Now try and draw a sphere. You will need to complete the ray intersection computation
in the Sphere class which is a subclass of SurfaceGeometry. You should see the sphere
rendered as a filled circle on your display.
• Complete the shading to include the ambient, diffuse, and specular reflection terms
according to the Phong reflection model. You need to take into account the position
of ray intersection with the surface as well as the positions of the light source and view
point. Implement this in the Material class.
• Complete the texture mapping procedure so that a 2d image can be pasted onto
any of the surfaces (planar and spherical). Do this by making a TextureMap class
in TextureMap.java.
• Try and create 6 planes and manipulate them so that they form the 6 faces of a cube.
Place the cube in the scene by treating it as a compound figure.
Requirements
With these tasks complete, use your project to generate a 3D graphics scene comprising
planar and spherical surfaces. It is possible to create impressive scenes using just these two
types of surfaces.
Marking
Basic surfaces
You will receive the marks as indicated, if your graphics scene showcases the following:
• A plane surface with a texture pasted on it.
[4 marks]
• A uniform colour sphere with a shiny surface (ie specular highlight)
[4 marks]
• A sphere with a texture pasted on it (eg the beachball)
[4 marks]
• The visible faces of a uniform colour cube correctly placed and shaded. The cube
should be located at any arbitrary position in the scene—not just aligned with the
principle axes in the world coordinates.
[5 marks]
Graphics Scene
Here you can create a scene using several instances of planes, spheres, and cubes. Marks will
be awarded for initiative. Be creative!
[4 marks]
Shadowing
Marks here will be earned if you can show shadows of objects in your scene. Here we are
using just a single point source of light for illumination. You can place this at any suitable
location in the scene. Use of ambient light can soften the shadows.
[4 marks]
Note
This assignment is to be completed using the ideas discussed in the lectures together with
your own Java programming skills. You are not being asked to do your own research in advanced APIs and toolkits. Do not use Java 3D, OpenGL, Vulkan, DirectX, Blender,
etc.
A graphical user interface is not required in this assignment. Your program should directly
display the rendered scene to the screen upon running the program. An additional class to
do this, Display, is provided in the startup code.
This assignment will count up to 25% of your final grade.
Due date: 2023 October 20 - 11:55 pm.