Random Terrain Assignment

Write a C++ program that implements the three random terrain algorithms discussed in class: random hills, particle deposition and random faults. Write three functions to implement the three algorithms.

Each function should receive a reference to a PGMImage object as the first parameter. You may include other parameters as appropriate to vary your algorithms. For example, you may write the random hill function so you can pass in the number of hills to create and a maximum height for each hill (so the actual height is chosen randomly from 0 to the maximum). In this case your function header would look like:

void randomHills(PGMImage &image, int numHills, int maxHeight)

The functions should add (or subtract or not) to the existing pixel values so that you can run your image through multiple functions.

The images you create should be 513 by 513 pixels, so we can use them in conjunction with Ogre. Use an image processing program e.g. Gimp to view them and convert them to a format Ogre can load. I recommend png.

Experiment with your algorithms' parameters and your OgreTerrain program from class. When you test them in your terrain renderer, you may want to set the WorldTexture and DetailTexture to terrain_texture.jpg and terrain_detail.jpg respectively although you may use other textures if you prefer.

Program Notes

• This is not an Ogre program, it is just a C++ console application that writes its output to a file.
• You may use any random number generator you wish, but if you provide your own, please submit it as well. I recommend using rand and srand for simplicity.
• You may alter the algorithms in anyway you would like as long as they maintain the general idea of the originals. For example, you might change the random hill algorithm to make the hill a different shape, or to create valleys instead.
• As you experiment with different parameters in your algorithms, you may change them where the functions are called an recompile. You do not have to prompt the user for this information.
• The heightmap related files can be found at http://cs.gettysburg.edu/~cpresser/cs391/terrain

Items to submit.

• Your program code (one cpp file will suffice, but you are welcome to do more).
• Your favorite image that your program created.
• A description of what you did to create the above image. Include which algorithms you used, what parameters you set and any other appropriate details.

Example Function

//add random values to every point in the terrain.
//values added will run from 1..max_amt
void randomTerrain(PGMImage &img, int max_amt){
  for(int y = 0; y < HEIGHT; y++){
    for(int x = 0; x < WIDTH; x++){
      int p = img.getPixel() + (rand() % max_amt) + 1;
      if(p > 255){
	p = 255;
      }
      img.setPixel(x, y, p);
    }
  }
}