public static Mesh GenerateTerrainMesh(float[,] heightMap, float heightScale,
AnimationCurve heightCurve, int LOD)
{
int width = heightMap.GetLength(0);
int height = heightMap.GetLength(1);
// The x and y position for the top left vertex on the mesh. In 3D, the represent the x and
// z values. This is used so we can make sure the center vertex of the heightMap will be
// at the center of the 3D world.
float topLeftX = (width - 1) / -2f;
float topLeftY = (height - 1) / 2f;
// Based on the LOD, the increment in which vertices are chosen.
int vertexSkip = 1;
if (LOD > 0)
{
vertexSkip = LOD * 2;
}
int verticesPerLine = (width - 1) / vertexSkip + 1;
// Log some info about vertex decrease
// int totalVertices = verticesPerLine * verticesPerLine;
// float vertexDecrease = (1f / ((width * height) / totalVertices)) * 100;
// Debug.Log("Vertices per line: " + verticesPerLine + "; Total: " + totalVertices +
// "; Vertex Decrease: " + vertexDecrease + "%");
// We need a TerrainData variable to store vertices and triangles for our terrain mesh.
TerrainData terrainData = new TerrainData(verticesPerLine, verticesPerLine);
// Loop through heights.
int vertexIndex = 0;
for (int y = 0; y < height; y += vertexSkip)
{
for (int x = 0; x < width; x += vertexSkip)
{
// Push a vertex to the end of the array, with the height pulled from the heightmap.
terrainData.vertices[vertexIndex] = new Vector3(topLeftX + x,
heightCurve.Evaluate(heightMap[x, y]) * heightScale, topLeftY - y);
// Push a uv mapping to the end of the array.
terrainData.uvData[vertexIndex] = new Vector2(x / (float)width, y / (float)height);
// Squares originate from the top left corners, so we ignore the vertices lining the
// right side and bottom of the vertex map.
if (x < width - 1 && y < height - 1)
{
// Add the bottom left triangle of the square to the mesh.
terrainData.AddTriangle(vertexIndex, vertexIndex + verticesPerLine + 1,
vertexIndex + verticesPerLine);
// Add the top right triangle of the square to the mesh.
terrainData.AddTriangle(vertexIndex + verticesPerLine + 1, vertexIndex, vertexIndex + 1);
}
vertexIndex++;
}
}
// Instead of directly creating and returning a mesh, we only return the mesh data. The
// reason for this is because Unity does not allow for creating meshes within a thread.
// Therefore, we must calculate the mesh data on the thread and create the mesh itself
// outside of it.
return(terrainData.ConstructMesh()); // this currently DOES return the mesh.
}
