Help drawing grid mesh for tile based game

Unity Engine
1

Hey guys,

I’m really stumped on this one. I’m trying to create a mesh to use as a grid for a tile-world, but I have REALLY screwed up the UV positioning. Can anyone tell me what I’ve done wrong?

using UnityEngine;
using System.Collections;

public class GridScript3 : MonoBehaviour {
	public GameObject theObj;
	public Material mat;
	
	int sectionsWidth = 100;
	int sectionsHeight = 100;
	Vector3 meshNormal = Vector3.up;
	
	
	// Use this for initialization
	void Start () {
		
		Mesh mesh = new Mesh();
		mesh.name = "testMesh";
		mesh.Clear();
				
		Vector3[] vertices = new Vector3[(sectionsWidth*sectionsHeight*4)];
		Vector2[] meshUVs = new Vector2[(sectionsWidth*sectionsHeight*4)];
		Vector3[] meshNormals = new Vector3[(sectionsWidth*sectionsHeight*4)];
		int[] meshTriangles = new int[3*(sectionsWidth*sectionsHeight)*2];
		
		int verticeIndex = 0;
		for(int i = 0; i < sectionsWidth; i++) {
			for(int j = 0; j < sectionsHeight; j++) {
				vertices[verticeIndex] = new Vector3((float)i, 0f, (float)(j));
				vertices[verticeIndex+1] = new Vector3((float)i+1, 0f, (float)(j));
				vertices[verticeIndex+2] = new Vector3((float)i, 0f, (float)(j)+1);
				vertices[verticeIndex+3] = new Vector3((float)i+1, 0f, (float)(j)+1);
				
				
				meshUVs[verticeIndex] = new Vector2(0f, 0f);
				meshUVs[verticeIndex+1] = new Vector2(1f, 0f);
				meshUVs[verticeIndex+2] = new Vector2(0f, 1f);
				meshUVs[verticeIndex+3] = new Vector2(1f,1f);
				
				meshNormals[verticeIndex] = meshNormal;
				meshNormals[verticeIndex+1] = meshNormal;
				meshNormals[verticeIndex+2] = meshNormal;
				meshNormals[verticeIndex+3] = meshNormal;
				
				verticeIndex += 4;
			}
		}
		
		int index = 0;
        for (int y = 0; y < sectionsWidth-1; y++) {
            for (int x = 0; x < sectionsWidth-1; x++) {
                // For each grid cell output two triangles
                meshTriangles[index++] = (y     * sectionsWidth) + x;
                meshTriangles[index++] = ((y+1) * sectionsWidth) + x;
                meshTriangles[index++] = (y     * sectionsWidth) + x + 1;
    
                meshTriangles[index++] = ((y+1) * sectionsWidth) + x;
                meshTriangles[index++] = ((y+1) * sectionsWidth) + x + 1;
                meshTriangles[index++] = (y     * sectionsWidth) + x + 1;
            }
        }
		
		mesh.vertices = vertices;
      	mesh.triangles = meshTriangles;
	 	mesh.normals = meshNormals;
		mesh.uv = meshUVs;
	
		MeshFilter mf = (MeshFilter)theObj.gameObject.GetComponent(typeof(MeshFilter));
		MeshRenderer mr = (MeshRenderer)theObj.gameObject.GetComponent(typeof(MeshRenderer));
		mf.mesh = mesh;
		//mr.renderer.material.color = Color.red;
		mr.renderer.material = mat;
		
		mesh.RecalculateBounds();
	}
	
	// Update is called once per frame
	void Update () {
	
	}
}

I know I’ve done something wrong and its probably very obvious. Please be kind :slight_smile:

720033--26141--$Screen shot 2011-10-19 at 9.58.54 PM.png
720033--26141--$Screen shot 2011-10-19 at 9.58.54 PM.png1300×507 92.2 KB

2

This is not a UV problem. All the blue in that image is your mesh wire frame so the triangulation is all wrong. Won’t matter if you have the UVs correct or not, that mesh is a mess.

I see in some previous posts you had that part sorted and working so maybe you changed something?

3

Yeah, with my earlier mesh, each quad shared vertices with it’s neighbours, which messed up all the uv mapping. This was my poor attempt to rectify it. I really need to stop trying to figure this out AFTER work. Brain no work good right now

4

A few other things:

  • You don’t have to call Clear() on a new Mesh.
  • Maybe try using Mesh.RecalculateNormals() and let the engine handle it instead of iterating and assigning them yourself. If nothing else it will cut down on the code you have to look at.

Now you get to deal with the extreme pain of per-vertex UV coordinates. This is by far the worst part of procedural mesh generation and I hate the fact that it’s a requirement.