public MeshGeometry GetPartialGeometry(int startIndex, int indexCount, int startVertex, int vertexCount)
{
var builder = new GeometryBuilder();
for (int i = 0; i < vertexCount; i++)
{
var v = Vertices[i + startVertex];
builder.AddVertex(v.Clone(), false);
}
var triangleIndices = GetTriangleIndices();
for (int i = 0; i < indexCount; i += 3)
{
int idx1 = triangleIndices[i + startIndex];
int idx2 = triangleIndices[i + 1 + startIndex];
int idx3 = triangleIndices[i + 2 + startIndex];
builder.AddTriangle(idx1 - startVertex, idx2 - startVertex, idx3 - startVertex);
}
var geom = builder.GetGeometry();
for (int i = 0; i < indexCount; i++)
{
var originalIndex = Indices[i + startIndex];
geom.Indices[i].RoundEdgeData = originalIndex.RoundEdgeData.Clone();
geom.Indices[i].AverageNormal = originalIndex.AverageNormal;
}
return(geom);
}
public static List <MeshGeometry> SplitSurfaces(MeshGeometry mesh)
{
var currentMesh = new GeometryBuilder();
var remainingTriangles = mesh.Triangles.ToList();
var resultingMeshes = new List <MeshGeometry>();
var edgeTriangleDic = new Dictionary <Edge, List <Triangle> >();
//var allEdges = remainingTriangles.SelectMany(x => x.Edges).Distinct();
foreach (var tri in remainingTriangles)
{
foreach (var edge in tri.Edges)
{
if (!edgeTriangleDic.ContainsKey(edge))
{
edgeTriangleDic.Add(edge, new List <Triangle>());
}
edgeTriangleDic[edge].Add(tri);
}
}
Triangle TakeTriangle(int index)
{
var result = remainingTriangles[index];
remainingTriangles.RemoveAt(index);
return(result);
}
IEnumerable <Triangle> GetNeighboringTriangles(Triangle triangle)
{
var neighbors = triangle.Edges.SelectMany(e =>
edgeTriangleDic[e]).Intersect(remainingTriangles).ToList();
foreach (var tri in neighbors)
{
remainingTriangles.Remove(tri);
}
foreach (var tri in neighbors.ToArray())
{
neighbors.AddRange(GetNeighboringTriangles(tri));
}
return(neighbors);
//for (int i = 0; i < remainingTriangles.Count; i++)
//{
// if (triangle.ShareEdge(remainingTriangles[i], false))
// {
// yield return TakeTriangle(i);
// i--;
// }
//}
}
while (remainingTriangles.Count > 0)
{
var curTri = TakeTriangle(0);
currentMesh.AddTriangle(curTri);
var neighbors = GetNeighboringTriangles(curTri);
foreach (var tri in neighbors)
{
currentMesh.AddTriangle(tri);
}
resultingMeshes.Add(currentMesh.GetGeometry());
currentMesh.Reset();
}
return(resultingMeshes);
}
