static void CalculateBounds(MeshImportJob jobData)
{
var upperBound = new Vector3(float.MinValue, float.MinValue, float.MinValue);
var lowerBound = new Vector3(float.MaxValue, float.MaxValue, float.MaxValue);
var count = jobData.Vertices.Length;
for (var i = 0; i < count; ++i)
{
var vertex = jobData.Vertices[i];
if (vertex.Position.x > upperBound.x)
{
upperBound.x = vertex.Position.x;
}
if (vertex.Position.y > upperBound.y)
{
upperBound.y = vertex.Position.y;
}
if (vertex.Position.z > upperBound.z)
{
upperBound.z = vertex.Position.z;
}
if (vertex.Position.x < lowerBound.x)
{
lowerBound.x = vertex.Position.x;
}
if (vertex.Position.y < lowerBound.y)
{
lowerBound.y = vertex.Position.y;
}
if (vertex.Position.z < lowerBound.z)
{
lowerBound.z = vertex.Position.z;
}
}
jobData.MeshBounds = new Bounds((lowerBound + upperBound) * 0.5f, upperBound - lowerBound);
}
static MeshImportJob ImportMesh <T>(SyncMesh syncMesh)
where T : struct
{
var data = new MeshImportJob {
SyncMesh = syncMesh
};
var toggle = new IndexToggle <T>(data);
var count = syncMesh.Vertices.Count;
data.Vertices = new Vertex[count];
for (var i = 0; i < count; ++i)
{
var v = syncMesh.Vertices[i];
data.Vertices[i].Position = new Vector3(v.X, v.Y, v.Z);
}
count = syncMesh.Normals.Count;
for (var i = 0; i < count; ++i)
{
var n = syncMesh.Normals[i];
data.Vertices[i].Normal = new Vector3(n.X, n.Y, n.Z);
}
count = syncMesh.Uvs.Count;
for (var i = 0; i < count; ++i)
{
var u = syncMesh.Uvs[i];
data.Vertices[i].UV = new Vector2(u.X, u.Y);
}
var subMeshCount = syncMesh.SubMeshes.Count;
var nbIndices = syncMesh.SubMeshes.Sum(x => x.Triangles.Count);
toggle.InstantiateArray(nbIndices);
data.SubMeshStarts = new int[syncMesh.SubMeshes.Count];
data.SubMeshLengths = new int[syncMesh.SubMeshes.Count];
var offset = 0;
for (var i = 0; i < subMeshCount; ++i)
{
count = syncMesh.SubMeshes[i].Triangles.Count;
data.SubMeshStarts[i] = offset;
data.SubMeshLengths[i] = count;
var index = 0;
foreach (var triangleIndex in syncMesh.SubMeshes[i].Triangles)
{
toggle.Set(offset + index++, triangleIndex);
}
offset += count;
}
CalculateBounds(data);
CalculateMeshTangents(data, toggle);
return(data);
}
static void CalculateMeshTangents <T>(MeshImportJob jobData, IndexToggle <T> toggle) where T : struct
{
// Todo: Validate that this function is yielding the same result as the internal unity function
var vertices = jobData.Vertices;
var triangleCount = toggle.GetLength();
var vertexCount = vertices.Length;
var tan1 = new Vector3[vertexCount];
var tan2 = new Vector3[vertexCount];
for (long a = 0; a < triangleCount; a += 3)
{
long i1 = toggle.Get(a + 0);
long i2 = toggle.Get(a + 1);
long i3 = toggle.Get(a + 2);
var v1 = vertices[i1].Position;
var v2 = vertices[i2].Position;
var v3 = vertices[i3].Position;
var w1 = vertices[i1].UV;
var w2 = vertices[i2].UV;
var w3 = vertices[i3].UV;
var x1 = v2.x - v1.x;
var x2 = v3.x - v1.x;
var y1 = v2.y - v1.y;
var y2 = v3.y - v1.y;
var z1 = v2.z - v1.z;
var z2 = v3.z - v1.z;
var s1 = w2.x - w1.x;
var s2 = w3.x - w1.x;
var t1 = w2.y - w1.y;
var t2 = w3.y - w1.y;
var div = s1 * t2 - s2 * t1;
var r = div == 0.0f ? 0.0f : 1.0f / (s1 * t2 - s2 * t1);
var sdir = new Vector3((t2 * x1 - t1 * x2) * r, (t2 * y1 - t1 * y2) * r, (t2 * z1 - t1 * z2) * r);
var tdir = new Vector3((s1 * x2 - s2 * x1) * r, (s1 * y2 - s2 * y1) * r, (s1 * z2 - s2 * z1) * r);
tan1[i1] += sdir;
tan1[i2] += sdir;
tan1[i3] += sdir;
tan2[i1] += tdir;
tan2[i2] += tdir;
tan2[i3] += tdir;
}
for (long a = 0; a < vertexCount; ++a)
{
var n = vertices[a].Normal;
var t = tan1[a];
Vector3.OrthoNormalize(ref n, ref t);
vertices[a].Tangent.Set(t.x, t.y, t.z, Vector3.Dot(Vector3.Cross(n, t), tan2[a]) < 0.0f ? -1.0f : 1.0f);
}
}
public IndexToggle(MeshImportJob jobData)
{
m_JobData = jobData;
}