Solved

2d tile based terrain generation

Posted on 2003-11-09
7
709 Views
Last Modified: 2012-06-21
I'm looking for some examples / algorithms to automatically allow me to create an array of numbers that represent a 2d terrain i.e.
11112111
11122221
11223221
11223221
11122221
etc - for a larger grid - where the numbers represent different land types i.e. 1 for water, 2 for land, 3 for rock/impassable land...

A purely random approach would not be good enough as it would leave rocks in the middle of water and random patches of water here and there.
Any ideas anyone?

cheers,

dc.
0
Comment
Question by:dcollis
  • 4
  • 2
7 Comments
 
LVL 15

Expert Comment

by:jimmack
Comment Utility
Taking the example you've shown above (it appears to be an island), you could try the following:

1) Set all locations to water
2) Create island (repeatedly if necessary)
2.1) Pick a random location for the centre of an island
2.2) Create the land for the whole island (replacing 1s with 2s)
2.3) Within the island, create the impassable region (replacing 2s with 3s)

This way, you'll always have islands surrounded by water and the impassable areas will only appear on land.  Also, it doesn't matter if the islands overlap.  This would just create larger islands.

The key to this technique is to build up the landscape from bottom up (a bit like oil painting ;-))
0
 
LVL 15

Expert Comment

by:jimmack
Comment Utility
Here's something to play with.  It starts with everything set to water, then builds up random rectangular islands.

import java.util.*;

public class Terrain
{
    private Random random = new Random();
    private int[][] terrain;
   
    private void createIsland()
    {
        int centerX = random.nextInt(terrain.length);
        int centerY = random.nextInt(terrain[0].length);
       
        terrain[centerX][centerY] = 2;
       
        int verticalStart = centerY - (random.nextInt(3) + 2);
        int horizontalStart = centerX - (random.nextInt(3) + 2);
        int verticalStop = centerY + (random.nextInt(3) + 2);
        int horizontalStop = centerX + (random.nextInt(3) + 2);
       
        verticalStart = Math.max(0, verticalStart);
        horizontalStart = Math.max(0, horizontalStart);
        verticalStop = Math.min(terrain[0].length, verticalStop);
        horizontalStop = Math.min(terrain.length, horizontalStop);

        for (int x = horizontalStart; x < horizontalStop; x++)
        {
            for (int y = verticalStart; y < verticalStop; y++)
            {
                if ((x > horizontalStart) &&
                    (x < (horizontalStop - 1)) &&
                    (y > verticalStart) &&
                    (y < (verticalStop - 1)))
                {
                    terrain[x][y] = 3;
                }
                else
                {
                    terrain[x][y] = 2;
                }
            }
        }
    }
   
    private void init()
    {
        terrain = new int[40][15];
       
        // Fill with water
        for (int x = 0; x < terrain.length; x++)
        {
            for (int y = 0; y < terrain[0].length; y++)
            {
                terrain[x][y] = 1;
            }
        }
       
        // Create islands
        for (int i = 0; i < 5; i++)
        {
            createIsland();
        }
    }
   
    private void display()
    {
        System.out.println("Terrain\n-------");
        for (int x = 0; x < terrain[0].length; x++)
        {
            for (int y = 0; y < terrain.length; y++)
            {
                System.out.print(terrain[y][x]);
            }
            System.out.println();
        }
    }
   
    public static void main(String args[])
    {
        Terrain t = new Terrain();
        t.init();
        t.display();
    }
}
0
 

Author Comment

by:dcollis
Comment Utility
I like this solution - its nice and quick and (when i play about with the variables a bit) creates some nice maps (I need all land connected to start with, so i changed it so that land would cover the area first and water would appear.

I will however, leave this question open a bit longer if you don't mind, to see if anyone else comes up with some other ideas

Thanks for the help so far,

dc.
0
How to run any project with ease

Manage projects of all sizes how you want. Great for personal to-do lists, project milestones, team priorities and launch plans.
- Combine task lists, docs, spreadsheets, and chat in one
- View and edit from mobile/offline
- Cut down on emails

 
LVL 15

Expert Comment

by:JakobA
Comment Utility
The 'philosophical' answer to your question ( and actually the same as jimmack is saying in practical terms :-))  is that you should be very carefull with your classification of 'area types'.
    1 for water, 2 for land, 3 for rock/impassable land...
should not be such an 'off the top of your head' decided list.
For one thing it is hieraical:
    1 for water, 2 for land, 2a for land with rock, 2b for land with forest, 1a for water with dangerous reefs, ...

by recognizing the hierachy there you are automatically led in the direction of jimmack's solution (I would not be surpriezed if that is just how he came to it).

For another thing we will want continuity, a checkerboard with black squares water and white squares land is neither believable nor usefull, so maybe we should introduce a landscape type 'beach' with the rule that beach squares must separate land and water.  1.5 for beach :-)

your choice of landscape types not just affect the evolution of your landscape, the landscape desired also to some extend suggest what landscape types you should chose.

regards JakobA
0
 
LVL 15

Accepted Solution

by:
jimmack earned 250 total points
Comment Utility
>> land would cover the area first and water would appear

You could probably create rivers with some nice recursive routines ;-)

>> I will however, leave this question open a bit longer if you don't mind

No problem.
0
 

Author Comment

by:dcollis
Comment Utility
Really sorry i left this question open so long. Totally forgot about it until i came to ask another question in this topic area today.

Sorry again,

dc.
0
 
LVL 15

Expert Comment

by:jimmack
Comment Utility
;-)  It's OK.  At least you didn't get a CleanupPing ;-)
0

Featured Post

Do You Know the 4 Main Threat Actor Types?

Do you know the main threat actor types? Most attackers fall into one of four categories, each with their own favored tactics, techniques, and procedures.

Join & Write a Comment

Suggested Solutions

Are you developing a Java application and want to create Excel Spreadsheets? You have come to the right place, this article will describe how you can create Excel Spreadsheets from a Java Application. For the purposes of this article, I will be u…
Introduction Java can be integrated with native programs using an interface called JNI(Java Native Interface). Native programs are programs which can directly run on the processor. JNI is simply a naming and calling convention so that the JVM (Java…
Viewers will learn about basic arrays, how to declare them, and how to use them. Introduction and definition: Declare an array and cover the syntax of declaring them: Initialize every index in the created array: Example/Features of a basic arr…
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.

763 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now