Description
In assignment 2, we will
create a small procedural
terrain based on Perlin noise,
texture the terrain based on
height, and place some
objects on the terrain
following the local normal
vector of the terrain.
(Note: Demo picture on the
right is created with a 4×4
random gradient grid and no
fractals.)
Assignment 2 and 3 are divided into two parts. Correctly completing all features the Basic
Requirements part will award you a grade up to 70% of the assignment. To get 100%, you
must selectively implement a few features in the Advanced Requirements part, whose
solutions are not completely covered in lectures and requires original research. The
Advanced Requirements are open-ended, and you are welcomed to propose and work on
your own preferred features. You should come to discuss your own idea with the TA or the
instructor first; and point values will be assigned to your proposed feature after we discuss it.
When you submit your assignment 2 and 3, you need to include a list of feature points that
you claim you have completed, and your TA will ask you questions about all feature points
you listed during the grading lab session. Downloading an existing Unity package/asset for a
feature is not considered as completing that feature by yourself.
Assignment 2 – Basic Requirements (70%)
1. Generate a square Perlin noise patch with sampling resolution 250×250. Tune the
frequency and amplitude of the noise to yield appealing results. (Hint: if you aren’t
sure what was the result of your Perlin noise generator, you can visualize this
250×250 2D float array as an image using the code from Assignment 1) (20%)
2. Generate a plane mesh that’s divided into a 250×250 grid, with each grid cell’s
rectangle conventionally divided into 2 triangles. (10%)
3. Using the Perlin noise patch generated in step 1 as a height map, elevate vertices
generated in (2) to form a procedural terrain. (10%)
4. Write a vertex/fragment shader pair of the terrain, which can texture the procedure
terrain with at least 4 different textures according to height. (Hint: You must compute
the height in the object space of the terrain model, which means if you move your
terrain mesh up and down in the Scene Editor, the texture distribution does not
change). (10%)
5. Implement the Phong-Blinn reflection model in the fragment shader, treating the
texture colour as surface albedo (Hint: you need camera position in the fragment
shader for specular reflection). (10%)
6. Place a few 3D models onto the procedural terrain, elevate them as the terrain goes
up, and rotate them so they seem to be upright on their local surface. (Hint: you need
to calculate the local normal of the procedure terrain). (10%)
Assignment 2 – Advanced Requirements (up to 30%)
● Add fractal Perlin noise to the heightfield and create height variation details on
different scales. (5%)
● Make a moveable camera so you can fly through the scene and examine your terrain
from any point of view. (5%)
● Scatter more models on to your mini-terrain, for example, other houses and little
towers. When place then randomly, write code to ensure that they don’t overlap each
other. (5%)
● Extend the procedural terrain to infinity (or to a very large area such that it looks like
infinite) while keeping a reasonable rendering performance. (10%)
● Add reflections to the water that not only reflects the skybox but also the
mountains/placed 3D models above the water. (10%)
● Add ripple effect to the water. (5%)
● Desaturate everything in the scene according to a fragment’s distance to the camera,
such that far away terrain & objects appear grey-ish and things closer to the camera
have more vibrant colour. (Hint: you need a method to adjust a pixel’s saturation only,
without changing its hue or luminance.) (10%)
● Add moving sun and clouds in the skybox, create a day/night cycle. (10%)
● Create atmospheric rendering effects for the environment – adjust the sunlight colour,
cloud colour, reflection and shadows according to the simulated time of the day and
the sun’s height from the horizon. (10%)
● Add interactive terrain editing features: when a user clicks on part of the terrain, s/he
can use the mouse to drag the terrain up and down. Surface features such as water
definition, texturing and small models must be updated in real time according to the
editing. (10%)
● Feel free to propose your own ideas and improvements for Advanced Requirements.
Your instructor/TA will assign a point value after discussing the idea with you.
