Changing terrain in real time

Questions & Answers
1

Hey guys, I’ll try and be specific as possible. Currently I’m looking at this extension (- YouTube), which seems to do exactly what I need, but the problem I have relates to updating the terrain in real time.

My goal is to have a SQL database with a table that stores the X and Y (of the grid) and the value which will correspond to what tile it would be. For example

  • 1 1 5
  • 1 2 10

On runtime, when read from the table, the tile at 1,1 will display tile 5. And then tile at 1,2 will display tile 10. But then if I were to change the the 5 to 20, for example, it will change the terrain in real time on the screen for the user.

I don’t necessarily need to implement a SQL table right now. I could just read from a txt file and modify to SQL later. My main issue is just updating the tile in real time with unity.

Amazing community :wink:

2

Hi, tenix

I’am not sure you mean about update an existing tile by some rules or about navigate on a huge number of tiles, so that below example is about create a tile.

The example is from my similar database, for a 3x3 tile:

1,3,1325
1,2,1337
1,1,1335
2,3,1325
2,2,1333
2,1,1329
3,3,1326
3,2,1331
3,1,1327

With these values retrieved as string (see xyzDb variable), you can use a script like (JS):

#pragma strict
var unitsStep : float = 30.0;
var material : Material;
private var height : int = 3;
private var width : int = 3;
private var area : int = width * height;
private var vertices = new Vector3[height * width];

var xyzDb="1,3,1325

1,2,1337
1,1,1335
2,3,1325
2,2,1333
2,1,1329
3,3,1326
3,2,1331
3,1,1327"; // Records from DB
var xzyValues = new String[area];

function Start() {

	xzyValues = xyzDb.Split(char.Parse("

"));

	gameObject.AddComponent(MeshCollider);
	gameObject.AddComponent(MeshFilter);
	gameObject.AddComponent(MeshRenderer);
	
	MakeTerrain();
	
}

function MakeTerrain() {

	if (material) {
		renderer.material = material;
	} else {
		renderer.material.color = Color.white;
	}

	/// Clean up
	var meshCollider : MeshCollider = gameObject.GetComponent(MeshCollider);
	meshCollider.sharedMesh = null;
	
	var terrain : Mesh = GetComponent(MeshFilter).mesh;
	terrain.Clear();

	// Build vertices
	var vertices = new Vector3[height * width];
	var uv = new Vector2[height * width];

	var uvScale = Vector2 (1/unitsStep,1/unitsStep);
	
	for (var j : int = 0;  j < xzyValues.Length ;  j++){
		
		var lle=xzyValues[j];
		var xyz=lle.Split(char.Parse(","));	

		var x : int = parseInt(xyz[0]);
		var z : int = parseInt(xyz[1]);
		var xx = x * unitsStep;
		var zz = z * unitsStep;

		var e : int = parseInt(xyz[2]);
		var vertex = Vector3 (xx, e, zz);
		vertices[j] = vertex;
		uv[j] = Vector2.Scale(Vector2 (xx, zz),uvScale);

												
	}
	
	// Assign vertices to terrain
	terrain.vertices = vertices;
	terrain.uv = uv;

	// Build triangle indices: 3 indices into vertex array for each triangle
	var triangles = new int[(height - 1) * (width - 1) * 6];
	var index = 0;
	for (z=0;z<height-1;z++)
	{
		for (x=0;x<width-1;x++)
		{
			// For each grid cell output two triangles
			triangles[index++] = (z     * width) + x;
			triangles[index++] = ((z+1) * width) + x;
			triangles[index++] = (z     * width) + x + 1;
			
			triangles[index++] = (z     * width) + x + 1;
			
			triangles[index++] = ((z+1) * width) + x;
			triangles[index++] = ((z+1) * width) + x + 1;
			
			
		}
	}

	// And assign them to the terrain
	terrain.triangles = triangles;
		
	// Auto-calculate vertex normals from the terrain
	terrain.RecalculateNormals();
	terrain.RecalculateBounds();
	terrain.Optimize();
	
	// Assign terrain mesh as collider mesh
	meshCollider.sharedMesh = terrain; 
	
}

Note terrain in the script is not about unity Terrains; I use it for meshes.
As suggestion regarding DB, for large areas it’s better to you use a NoSQL database, recording for example 1_1 as key and 5 as value, 1_2 as key and 10 and so (exploding by x/z coordinates by “_”).
Then, retrieve records in needed range.