4 replies to this topic

[Divega]

[THIS STUPID EDITOR WILL NOT FORMAT THE TEXT CORRECTLY]

Hey there GameDevs,

I'm having trouble grasping a few concepts about using binary triangle trees for representing terrain data. Lets say I'm working with a 17x17 square grid of vertices and i have a class as follows:

public class Terrain {
private int maxWidth;
private int numVertices;
private float[][] heightmap;
public Terrain(int gridWidth) { // 16 assuming each grid cell's length and width = 1;
this.maxWidth = gridWidth + 1; // 17
this.numVertices = this.maxWidth * this.maxWidth; // 289
System.out.println(this.numVertices);
this.heightmap = new float[this.maxWidth][this.maxWidth]; // 17x17
for(int x = 0; x < this.maxWidth; x++) {
for(int z = 0; z < this.maxWidth; z++) {
this.heightmap[x][z] = 0; // Zero out height data;
}
}
}
}

Bounds of terrain:


The vertices would be contained in a vertex buffer from 0 - 289; Each 1x1 cell contains 2 triangles and total of 4 vertices / 6 indices.

So what I am not grasping is how to represent this data using a BTT. The way I understand a BTT is

BTT {
data
leftchild
rightchild
}

Now I'm assuming the data variable in each tree would be an index buffer of the 3 indices for the triangle. This biggest thing i struggle with is how do I keep track of the left, right, and bottom neighbor of each triangle without being able to pass data by reference. Please let me know if you need anymore information from me, this is all i can think up right now.

Edited by Divega, 17 October 2012 - 09:25 PM.

[Ashaman73]

[THIS STUPID EDITOR WILL NOT FORMAT THE TEXT CORRECTLY]

It formats 
    the text 
		   the way 
			    the user want 
					   it....

Back to your problem: take a look here.

[Divega]

Thanks for the reply however, I've already read through that link a few times. It does not answer my question

The biggest thing i struggle with is how do I keep track of the left, right, and bottom neighbor of each triangle without being able to pass data by reference.

Nor does it supply the source that it says is included with the article.

[MrOMGWTF]

[THIS STUPID EDITOR WILL NOT FORMAT THE TEXT CORRECTLY]

public class Terrain {
	private int maxWidth;
	private int numVertices;
	private float[][] heightmap;
	
	public Terrain(int gridWidth) { // 16 assuming each grid cell's length and width = 1;
		this.maxWidth = gridWidth + 1; // 17
		this.numVertices = this.maxWidth * this.maxWidth; // 289
		System.out.println(this.numVertices);
		this.heightmap = new float[this.maxWidth][this.maxWidth]; // 17x17
		
		for(int x = 0; x < this.maxWidth; x++) {
			for(int z = 0; z < this.maxWidth; z++) {
				this.heightmap[x][z] = 0; // Zero out height data;
			}
		}
	}
}

It works... lrn2bbcode ;_;

[Divega]

Extremely helpful, high five sir. Please try again.