/// <summary>
/// Recursively split node across its pivot axis.
/// </summary>
/// <param name="node">KDTreeNode to split</param>
/// <param name="depth">Current recursion depth, set lower if you get stack overflow</param>
/// <returns>True if split was a success or max_depth/max_node_size criterion met</returns>
bool BuildNode(KDNodeJeremyC node, int depth)
{
if (depth >= MaxNodeDepth)
{
return(true);
}
if (node.Indices.Count <= MaxNodeSize)
{
return(true);
}
foreach (var index in node.Indices)
{
VertexKDTree vertex = TreeVectors[index];
if (!node.IsBuilt)
{
node.Build();
}
KDNodeJeremyC child = node.GetSplitNode(vertex);
child.AddVertex(index, vertex);
}
// TODO: Do we need to check if either child is empty? Since we're calculating the split axis
// using raw data it's unlikely.
node.Clear();
node.ChildLeft.Build();
node.ChildRight.Build();
BuildNode(node.ChildLeft, depth + 1);
BuildNode(node.ChildRight, depth + 1);
return(true);
}
///// <summary>
///// Add a new vertex/point to the KDTree build process. Points must be added before calling KDTree.Build()
///// </summary>
///// <param name="vertex">3D vertex</param>
//public void AddPoint(VectorWithIndex vertex)
//{
// Vectors.Add(vertex);
//}
///// <summary>
///// Add a new vertex/point to the KDTree build process. Points must be added before calling KDTree.Build()
///// </summary>
///// <param name="x">VectorWithIndex.x</param>
///// <param name="y">VectorWithIndex.y</param>
///// <param name="z">VectorWithIndex.z</param>
//public void AddPoint(float x, float y, float z)
//{
// Vectors.Add(new VectorWithIndex(new Vector3(x,y,z), -1));
//}
/// <summary>
/// Add a new list of vertices/points to the KDTree build process. Points must be added before calling KDTree.Build()
/// </summary>
/// <param name="vertex">List of 3D vertices</param>
//public void AddPoints(List<VectorWithIndex> vertices)
//{
// Vectors = Vectors.Concat(vertices).ToList();
//}
///// <summary>
///// Add a new list of vertices/points to the KDTree build process. Points must be added before calling KDTree.Build()
///// </summary>
///// <param name="vertex">List of 3D vertices stored as a 1D array w/ every 3 elements defining a vertex.</param>
//public void AddPoints(List<float> vertices)
//{
// int element_size = 3;
// if (vertices.Count % element_size != 0) return; //vertex count must be a multiple of element_size
// for(int i = 0; i < vertices.Count; i+=element_size){
// float x = vertices[i];
// float y = vertices[i+1];
// float z = vertices[i+2];
// Vectors.Add(new VectorWithIndex(new Vector3(x, y, z), -1));
// }
//}
/// <summary>
/// Build KDTree
/// </summary>
/// <notes>
/// Points are added via KDTree.AddPoint(s) methods, the Build process uses
/// those points to create the final tree. If new points are added after a
/// tree has been built, a new tree must be created.
/// </notes>
/// <returns></returns>
public bool Build(PointCloud pcTarget)
{
this.targetTreee = pcTarget;
this.treePointCloud = pcTarget;
this.TreeVectors = treePointCloud.VectorsWithIndex;
if (VertexCount <= 0)
{
Console.WriteLine("[Warning] - No vertices added to KDTree, aborting build.");
return(false);
}
Root = new KDNodeJeremyC(); // { SplitAxis = largest_split_axis, AABB = new BoundingBoxAxisAligned(min,max), MidPoint = center, Parent = null};
{ // Fill the Root
int index = 0;
foreach (var vertex in TreeVectors)
{
root.AddVertex(index, vertex);
index++;
}
}
BuildNode(Root, 0);
return(true);
}