//fix pole vertices incorrect U
private static Dictionary <int, float> FindAndFixPoleVertices(IPlatonicSolid solid, ref List <TriangleFace> faces, ref List <Vector3> vertices)
{
Vector3 north = solid.NorthPole;
Vector3 south = -solid.NorthPole;
List <int> poleVerticeInd = new List <int>();
Dictionary <int, float> poleVertIndicesCorrectU = new Dictionary <int, float>();
foreach (TriangleFace face in faces)
{
if (vertices[face.IndA] == north || vertices[face.IndA] == south)
{
if (!poleVerticeInd.Contains(face.IndA))
{
poleVerticeInd.Add(face.IndA);
}
else
{
vertices.Add(vertices[face.IndA] == north ? north : south);
face.SetIndA(vertices.Count - 1);
}
float xCoordB = GetUvCoordinates(vertices[face.IndB]).x;
float xCoordC = GetUvCoordinates(vertices[face.IndC]).x;
float correctedU = (xCoordB + xCoordC) / 2f + 0.5f; // I am not sure why it is needed but it seems needed...
poleVertIndicesCorrectU[face.IndA] = correctedU;
}
}
return(poleVertIndicesCorrectU);
}
private void GenerateSphereMeshThread(object obj)
{
if (SphereType == SphereType.uvsphere)
{
_sphereMesh = UvSphereBuilder.Generate(Radius, Resolution);
}
else
{
IPlatonicSolid baseSolid = GetBaseSolid(SphereType);
_sphereMesh = SphereBuilder.Build(baseSolid, Radius, Resolution, Smooth, RemapVertices);
}
Debug.Log(SphereType.ToString() + " generated: " + _sphereMesh.Triangles.Length + " tris and " + _sphereMesh.Vertices.Length + " verts.");
}
/// <summary>
/// Generate a UV sphere.
/// </summary>
/// <param name="resolution">Number of latitude lines (vertices on the y axis).</param>
public static MeshData Build(IPlatonicSolid platonic, float radius, int resolution, bool smooth, bool remapVertices)
{
List <Vector3> vertices = new List <Vector3>();
List <int> triangles = new List <int>();
List <TriangleFace> faces = new List <TriangleFace>();
Dictionary <long, int> middlePointIndexCache = new Dictionary <long, int>();
Dictionary <int, int> vertWithWarpedU = new Dictionary <int, int>();
Dictionary <int, float> poleVertIndicesCorrectU = new Dictionary <int, float>();
Vector2[] uv;
Vector3[] normals;
Vector4[] tangents;
Vector4 tangent = new Vector4(1f, 0f, 0f, -1f);
// create the base cube primitive
vertices = platonic.Vertices;
faces = platonic.Faces;
// subdivide the triangles faces
for (int i = 1; i < resolution; i++)
{
List <TriangleFace> newFaces = new List <TriangleFace>();
foreach (var tri in faces)
{
// replace triangle by 4 triangles
int a = GetMiddlePoint(tri.IndA, tri.IndB, ref vertices, ref middlePointIndexCache);
int b = GetMiddlePoint(tri.IndB, tri.IndC, ref vertices, ref middlePointIndexCache);
int c = GetMiddlePoint(tri.IndC, tri.IndA, ref vertices, ref middlePointIndexCache);
newFaces.Add(new TriangleFace(tri.IndA, a, c));
newFaces.Add(new TriangleFace(tri.IndB, b, a));
newFaces.Add(new TriangleFace(tri.IndC, c, b));
newFaces.Add(new TriangleFace(a, b, c));
}
faces = newFaces;
}
// fix warped uv on seam
vertWithWarpedU = FindAndFixeWarpedFaces(ref faces, ref vertices);
poleVertIndicesCorrectU = FindAndFixPoleVertices(platonic, ref faces, ref vertices);
// makes unique vertice to have a non smooth sphere
if (!smooth)
{
MakeVerticesUnique(ref faces, ref vertices, ref vertWithWarpedU, ref poleVertIndicesCorrectU);
}
// create mesh triangles
for (int i = 0; i < faces.Count; i++)
{
triangles.Add(faces[i].IndA);
triangles.Add(faces[i].IndB);
triangles.Add(faces[i].IndC);
}
if (remapVertices)
{
vertices = platonic.RemapVertices(vertices, faces);
}
// generate uv, normals, and tangents
uv = new Vector2[vertices.Count];
normals = new Vector3[vertices.Count];
tangents = new Vector4[vertices.Count];
for (int i = 0; i < vertices.Count; i++)
{
Vector3 normal = vertices[i].normalized;
float u = (Mathf.Atan2(normal.z, normal.x) / (2f * Mathf.PI)) + 0.5f; // remove the 0.5f
float v = (Mathf.Asin(normal.y) / Mathf.PI) + 0.5f;
vertices[i] = normal * radius;
// correct uv issues
if (poleVertIndicesCorrectU.ContainsKey(i))
{
u = poleVertIndicesCorrectU[i];
}
if (vertWithWarpedU.ContainsValue(i))
{
u += 1;
}
if (vertWithWarpedU.ContainsValue(i) && poleVertIndicesCorrectU.ContainsKey(i))
{
u -= 0.5f; // found through trial and error, it was working so I had to remove the 0.5 added when recalculating
}
uv[i] = new Vector2(u, v);
normals[i] = normal;
tangents[i] = tangent;
}
// recompute normals
if (!smooth)
{
foreach (TriangleFace face in faces)
{
Vector3 normal = GetFaceCenter(face, vertices);
normals[face.IndA] = normal;
normals[face.IndB] = normal;
normals[face.IndC] = normal;
}
}
return(new MeshData(vertices.ToArray(), triangles.ToArray(), uv, normals, tangents));
}
