private static void BuildTopDown(BVHNode node, Action <string> logger)
{
int iterations = 0;
var queue = new Queue <BVHNode>();
queue.Enqueue(node);
BVHNode current = null;
while (queue.Count > 0)
{
++iterations;
current = queue.Dequeue();
if (current.Items.Length > MinPartitionSize)
{
var boundingSphere = current.BoundingSphere;
var splitOrder = GetSplitOrder(boundingSphere.Center);
foreach (var split_dim in splitOrder)
{
var leftSpheres = new List <Sphere>();
var rightSpheres = new List <Sphere>();
var split_coord = 0.5f * ValueAt(boundingSphere.Center, split_dim);
foreach (var sphere in current.Items)
{
if (ValueAt(sphere.Center, split_dim) < split_coord)
{
leftSpheres.Add(sphere);
}
else
{
rightSpheres.Add(sphere);
}
}
var split_success
= leftSpheres.Count > 0 &&
rightSpheres.Count > 0;
if (split_success)
{
current.Left = new BVHNode(leftSpheres.ToArray());
queue.Enqueue(current.Left);
current.Right = new BVHNode(rightSpheres.ToArray());
queue.Enqueue(current.Right);
current.ClearItems();
break;
}
}
}
}
logger($"BVH constructed in '{iterations}' iterations.");
}
