// Generate the mesh of the face.
public void ConstructMesh()
{
// Array of vertices (points on the plane)
Vector3[] vertices = new Vector3[resolution * resolution];
// Calculate the amount of triangles within the plane given the amount of vertices.
int[] triangles = new int[(resolution - 1) * (resolution - 1) * 6];
int triIndex = 0; // The current index (point) we are drawing the triangle from.
Vector2[] uv = (mesh.uv.Length == vertices.Length) ? mesh.uv : new Vector2[vertices.Length]; // Ensure UVs are the correct size so it is consistent with planet resolution.
for (int y = 0; y < resolution; y++)
{
for (int x = 0; x < resolution; x++)
{
// Calculates the current index (which triangle we are creating).
int i = x + y * resolution;
// Keeps track of how complete the mesh is, used to define where the vertex should be on the face.
Vector2 percent = new Vector2(x, y) / (resolution - 1);
// Places a vertex on the cube using the percent value above; the axes, which tells us how far along each axis we are; and the current shape settings.
Vector3 pointOnUnitCube = localUp + (percent.x - 0.5f) * 2 * axisA + (percent.y - 0.5f) * 2 * axisB;
Vector3 pointOnUnitSphere = pointOnUnitCube.normalized; // Create a sphere by making all vertices the same distance away from the center.
float unscaledElevation = shapeGenerator.CalculateUnscaledGeneration(pointOnUnitSphere);
vertices[i] = pointOnUnitSphere * shapeGenerator.GetScaledElevation(unscaledElevation);
// Get UV data.
uv[i].y = unscaledElevation;
// We divide the squares in the mesh into two triangles using the following formulas:
// i, i + r (resolution, or number of vertices per line) + 1, i + r to determine the points of the first triangle.
// i, i + 1, i + r + 1 for the second triangle.
if (x != resolution - 1 && y != resolution - 1)
{
// first triangle
triangles[triIndex] = i; // first vertex of first triangle
triangles[triIndex + 1] = i + resolution + 1; // second vertex of first triangle
triangles[triIndex + 2] = i + resolution; // third vertex of first triangle
// second triangle
triangles[triIndex + 3] = i; // first vertex of second triangle
triangles[triIndex + 4] = i + 1; // second vertex of second triangle
triangles[triIndex + 5] = i + resolution + 1; // third vertex of second triangle
triIndex += 6; // added six vertices, so we increment the current index by six.
}
}
}
// Clears current mesh data just in case we are viewing the face at a lower resolution, so nonexistent indeces are no longer referenced.
mesh.Clear();
// Assign data to the mesh. Ensures that data is not lost upon regeneration.
mesh.vertices = vertices;
mesh.triangles = triangles;
mesh.RecalculateNormals();
mesh.uv = uv;
}
