public BVH(List <Mesh> allMeshes)
{
//Build the BVH
List <int> meshIndices = new List <int>();
for (int i = 0; i < allMeshes.Count; i++)
{
meshIndices.Add(i);
}
_root = new BVHNode(meshIndices, allMeshes);
}
private void Subdivide(List <Mesh> allMeshes)
{
List <int> leftSide = null;
List <int> rightSide = null;
float minimalSplitCost = float.MaxValue;
float boxWidth = Math.Abs(bounds.minX - bounds.maxX);
float boxHeight = Math.Abs(bounds.minY - bounds.maxY);
float boxForward = Math.Abs(bounds.minZ - bounds.maxZ);
int splitPlaneCount = Config.BINNING_SPLIT_PLANE_COUNT;
GenerateBins(allMeshes, splitPlaneCount, boxWidth, boxHeight, boxForward, out List <List <int> > xBins, out List <List <int> > yBins, out List <List <int> > zBins);
for (int i = 0; i < 3; i++) //0 = X, 1 = Y, 2 = Z
{
for (int j = 0; j < splitPlaneCount; j++)
{
float splitCost = SplitCost(i, j, allMeshes, xBins, yBins, zBins, out List <int> leftSideMeshes, out List <int> rightSideMeshes);
if (splitCost < minimalSplitCost)
{
leftSide = leftSideMeshes;
rightSide = rightSideMeshes;
minimalSplitCost = splitCost;
}
}
}
if (minimalSplitCost >= bounds.SurfaceArea() * meshIndices.Count)
{
isLeaf = true;
return;
}
leftChildNode = new BVHNode(leftSide, allMeshes);
rightChildNode = new BVHNode(rightSide, allMeshes);
}
private void SubdivideWithAlternativeBinningMethod(List <Mesh> allMeshes)
{
List <int> leftSide = new List <int>();
List <int> rightSide = new List <int>();
float minimalSplitCost = float.MaxValue;
float boxWidth = Math.Abs(bounds.minX - bounds.maxX);
float boxHeight = Math.Abs(bounds.minY - bounds.maxY);
float boxForward = Math.Abs(bounds.minZ - bounds.maxZ);
int splitBins = Config.BINNING_SPLIT_PLANE_COUNT;
for (int i = 0; i < 3; i++) //0 = X, 1 = Y, 2 = Z
{
float binSize = i == 0 ? boxWidth / splitBins : (i == 1 ? boxHeight / splitBins : boxForward / splitBins);
for (int j = 0; j < splitBins; j++)
{
float splitInterval = j * binSize;
float splitCost = SplitCostWithAlternativeBinningMethod(i, splitInterval, allMeshes, out List <int> leftSideMeshes, out List <int> rightSideMeshes);
if (splitCost < minimalSplitCost)
{
leftSide = leftSideMeshes;
rightSide = rightSideMeshes;
minimalSplitCost = splitCost;
}
}
}
if (minimalSplitCost >= bounds.SurfaceArea() * meshIndices.Count)
{
isLeaf = true;
return;
}
leftChildNode = new BVHNode(leftSide, allMeshes);
rightChildNode = new BVHNode(rightSide, allMeshes);
}