COMP3170 Assignment 3

Objectives

This assignment covers the following topics:

• 3D modelling with triangular meshes

• 3D Transformations

• Perspective cameras

• Illumination and shading

• Texturing

• Transparency

Your task is to build a simple 3D world using height-mapped terrain, with water and lighting 

effects like this.

Framework

A basic framework for the assignment is available via GitHub classroom:

https://classroom.github.com/a/p3fFYFbF

Level files

The assignment framework includes a class that loads a level definition from a JSON file. 

This file includes the following data:

level.json – an example level

{

 "name" : "Island”,

"map" : {

"width" : 11,

"depth" : 11,

"height" : [

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 

0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,

0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 0,

0, 1, 0, 1, 2, 2, 2, 1, 0, 1, 0,

0, 1, 0, 1, 3, 3, 3, 1, 0, 1, 0,

0, 1, 0, 1, 4, 4, 4, 1, 0, 1, 0,

0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0,

0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0,

0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,

]

},

"waterHeight" : 2,

}

This defines height map, consisting of a 11x11 grid of points with different heights, with 

water covering everything up to height 2. 

The resulting scene would look like this:

(Note this doesn’t include texturing or ripple effects described later)

A simple framework has been provided to read these files Java objects. Your assignment 

should support this basic level format, and render any level that meets this spec.

Scene features

Your mark will be based on the features you implement, from the list below. Each feature 

has a mark value attached. Completing more than 100% worth of features will not earn 

additional marks.

Feature Marks

Terrain

- Heightmap mesh generation

- Diffuse & ambient lighting 

(smooth fragment lighting)

- Texturing (one texture)

- Texture blending with terrain height

40%

20%

10%

5%

Water

- Diffuse & ambient lighting

- Transparency

- Specular lighting

- Ripple effect

5%

5%

10%

5%

Camera

- Fly through camera 5%

Light

- Animated sun 5%

General requirements

Your scene should be implemented using:

1) Anti-aliasing using 4x supersampling.

2) Backface culling

3) Mipmaps for all textures (with trilinear filtering)

4) Gamma correction (with a default gamma of 2.2)

Terrain

Height map mesh generation: 40%

Use the height-map data provided to generate a 3D mesh. The mesh should consist of width 

by depth points (for the values specified in the level file) spaced in a grid in the x/z axes. The 

y-coordinate of each point is given by the corresponding value in the height array. These 

points should be joined into a mesh of triangles. So, a 20 by 20 height map will have 19x19 

squares each represented with two triangles, as shown below.

Diffuse & ambient lighting: 20%

You should provide a terrain shader that implements diffuse and ambient lighting with the 

following specs:

- Smooth Phong shading (i.e. in the fragment shader)

- Appropriate vertex normals computed by interpolating the face normals of 

surrounding triangles

- Point light source determined by the position of the sun in the scene.

Texturing: 10%

The terrain shader should use a texture to determine the diffuse reflection coefficient of the 

terrain. The texture should be tiled so each 1x1 square of the terrain contains 1 repetition of 

the texture. Some appropriate textures are provided in the assignment framework, or you 

can use a texture of your own choosing, as long as you have a license to use and distribute 

it. Sources for all third-party assets should be documented in your report.

Textures should use mipmaps and trilinear filtering. Gamma correction should be applied 

(with a default gamma of 2.2).

Texture-blending: 10%

Multiple textures (e.g. grass and rock) are used at different terrain heights (at your 

discretion), with appropriate blending where they meet. (E.g. underwater terrain could use 

a sand texture while above water is textured with grass).

Water

The water should be a single rectangle with width (x) and depth (z) dimensions to cover the 

entire terrain. It should sit at the height specified by the ‘waterDepth’ property in the level 

file. You should provide a specialised water shader to colour this.

Diffuse & ambient lighting: 5%

The water shader should implement ambient and diffuse lighting. 

Transparency: 5%

The water should be semi-transparent showing the terrain below.

Specular lighting: 5%

The water shader should also implement smooth specular lighting, reflecting the light