Author: Eric Sunalp

Email: cyberplx@cats.ucsc.edu

CMPS161

 

This program has two parts, the terrain generator and the ball-bouncing simulator. The user first starts by launching the terrain generator. The user can either ask for a random terrain of a specified size based on mathematical equations (like the one above) or the user can generate a terrain from a grayscale image.
 

A Grayscale Image
 

Example Of The Terrain Generated
 

I designed the terrain generator by outputting x y z and values to a text file based on a mathematical equation. I also added in the ability to convert grayscale images to complex terrain data. Height values are determines based on their RGB value.

When the terrains are read in I first load the vertices from the file and then create triangles for all the vertices in the grid. The next step is to generate all the normal vectors for each triangle plan in order to get the proper lighting in the scene. These normals are also used later to determine the bounce direction of the balls.

When a ball is dropped it gains a constant velocity due to gravity. A direction vector for each ball is also instantiated at this time. The ball continues to fall, at every step checking to see if it has collided with its complex terrain. The check is made by only looking at neighboring triangles in the terrain and seeing if the ball is above their depth values. Note that this includes the balls radius. Once the ball collides with the terrain a calculation is made with the direction vector of the ball and the normal vector of the triangle and the ball bounces in the correct direction. Also note that important physics are implemented such as reducing the balls velocity (energy) when it hits an object.

 
Launch with: "terrainGen -r 50 50 0.5 file"

 
-r

will use a random math function to generate the terrain

 
50 50

will make a terrain 50 by 50

 
0.5

is the resolution and should be from 0 to 1

 
file

is the output file to save the generated terrain

 
or

 
Launch with: "terrainGen -I image 0.5 file"

-I

tells the program to use an image file to generate the terrain.

Image

is the name of the image file. This should be of type .sgi or .rgb

0.5

is the resolution and should be from 0 to 1

file

is the output file to save the generated terrain

Launch the simulator by typing "final"

Once the app is launched you can type any of the following command:

 
Escape

will quit the app

Q

will quit the app

 
L

will ask you for a terrain file to load in the terminal

 
R

will reset your view

 
Z

will cause the first mouse button to rotate the world around the z axis

 
A

will ask you to add a new ball in the terminal

 
S

will start the animation and ask you for a time step in the terminal

 
B

will reset the balls positions

 
You can also use the mouse to orient the world

 
LEFT BUTTON

will rotate the world

 
MIDDLE BUTTON

will translate the world along the z axis

 
RIGHT BUTTON

will translate the world along the x and y axis