public OctreeNode crearOctree(List<TgcMesh> modelos, TgcBoundingBox sceneBounds)
{
OctreeNode rootNode = new OctreeNode();
Vector3 pMax = sceneBounds.PMax;
Vector3 pMin = sceneBounds.PMin;
//Calcular punto medio y centro
Vector3 midSize = sceneBounds.calculateAxisRadius();
Vector3 center = sceneBounds.calculateBoxCenter();
//iniciar generacion recursiva de octree
doSectorOctreeX(rootNode, center, midSize, 0, modelos);
//podar nodos innecesarios
deleteEmptyNodes(rootNode.children);
//eliminar hijos que subdividen sin necesidad
//deleteSameMeshCountChilds(rootNode);
//imprimir por consola el octree
//printDebugOctree(rootNode);
//imprimir estadisticas de debug
//printEstadisticasOctree(rootNode);
return rootNode;
}
/// <summary>
/// Dibujar meshes que representan los sectores del Octree
/// </summary>
public List<TgcDebugBox> createDebugOctreeMeshes(OctreeNode rootNode, TgcBoundingBox sceneBounds)
{
Vector3 pMax = sceneBounds.PMax;
Vector3 pMin = sceneBounds.PMin;
List<TgcDebugBox> debugBoxes = new List<TgcDebugBox>();
doCreateOctreeDebugBox(rootNode, debugBoxes,
pMin.X, pMin.Y, pMin.Z,
pMax.X, pMax.Y, pMax.Z, 0);
return debugBoxes;
}
/// <summary>
/// Crear nuevo Octree
/// </summary>
/// <param name="modelos">Modelos a optimizar</param>
/// <param name="sceneBounds">Límites del escenario</param>
public void create(List<TgcMesh> modelos, TgcBoundingBox sceneBounds)
{
this.modelos = modelos;
this.sceneBounds = sceneBounds;
//Crear Octree
this.octreeRootNode = builder.crearOctree(modelos, sceneBounds);
//Deshabilitar todos los mesh inicialmente
foreach (TgcMesh mesh in modelos)
{
mesh.Enabled = false;
}
}
/// <summary>
/// Corte con plano Y
/// </summary>
private void doSectorOctreeY(OctreeNode parent, Vector3 center, Vector3 size, int step,
List<TgcMesh> meshes, int childIndex)
{
float y = center.Y;
//Crear listas para realizar corte
List<TgcMesh> possitiveList = new List<TgcMesh>();
List<TgcMesh> negativeList = new List<TgcMesh>();
//Y-cut
Plane yCutPlane = new Plane(0, 1, 0, -y);
splitByPlane(yCutPlane, meshes, possitiveList, negativeList);
//recursividad de positivos con plano Z, usando resultados positivos y childIndex 0
doSectorOctreeZ(parent, new Vector3(center.X, y + size.Y / 2, center.Z),
new Vector3(size.X, size.Y / 2, size.Z),
step, possitiveList, childIndex + 0);
//recursividad de negativos con plano Z, usando plano X negativo y childIndex 2
doSectorOctreeZ(parent, new Vector3(center.X, y - size.Y / 2, center.Z),
new Vector3(size.X, size.Y / 2, size.Z),
step, negativeList, childIndex + 2);
}
/// <summary>
/// Corte con plano X
/// </summary>
private void doSectorOctreeX(OctreeNode parent, Vector3 center, Vector3 size,
int step, List<TgcMesh> meshes)
{
float x = center.X;
//Crear listas para realizar corte
List<TgcMesh> possitiveList = new List<TgcMesh>();
List<TgcMesh> negativeList = new List<TgcMesh>();
//X-cut
Plane xCutPlane = new Plane(1, 0, 0, -x);
splitByPlane(xCutPlane, meshes, possitiveList, negativeList);
//recursividad de positivos con plano Y, usando resultados positivos y childIndex 0
doSectorOctreeY(parent, new Vector3(x + size.X / 2, center.Y, center.Z),
new Vector3(size.X / 2, size.Y, size.Z),
step, possitiveList, 0);
//recursividad de negativos con plano Y, usando resultados negativos y childIndex 4
doSectorOctreeY(parent, new Vector3(x - size.X / 2, center.Y, center.Z),
new Vector3(size.X / 2, size.Y, size.Z),
step, negativeList , 4);
}
/// <summary>
/// Hacer visible las meshes de un nodo si es visible por el Frustum
/// </summary>
private void testChildVisibility(TgcFrustum frustum, OctreeNode childNode,
float boxLowerX, float boxLowerY, float boxLowerZ, float boxUpperX, float boxUpperY, float boxUpperZ)
{
if (childNode == null)
{
return;
}
//test frustum-box intersection
TgcBoundingBox caja = new TgcBoundingBox(
new Vector3(boxLowerX, boxLowerY, boxLowerZ),
new Vector3(boxUpperX, boxUpperY, boxUpperZ));
TgcCollisionUtils.FrustumResult c = TgcCollisionUtils.classifyFrustumAABB(frustum, caja);
//complementamente adentro: cargar todos los hijos directamente, sin testeos
if (c == TgcCollisionUtils.FrustumResult.INSIDE)
{
addAllLeafMeshes(childNode);
}
//parte adentro: seguir haciendo testeos con hijos
else if (c == TgcCollisionUtils.FrustumResult.INTERSECT)
{
findVisibleMeshes(frustum, childNode, boxLowerX, boxLowerY, boxLowerZ, boxUpperX, boxUpperY, boxUpperZ);
}
}
private void obtenerEstadisticas(OctreeNode node, ref int minModels, ref int maxModels)
{
if (node.isLeaf())
{
int n = node.models.Length;
if (n < minModels)
minModels = n;
if (n > maxModels)
maxModels = n;
}
else
{
for (int i = 0; i < node.children.Length; i++)
{
obtenerEstadisticas(node.children[i], ref minModels, ref maxModels);
}
}
}
/// <summary>
/// Imprime estadisticas del Octree
/// </summary>
private void printEstadisticasOctree(OctreeNode rootNode)
{
Console.WriteLine("*********** Octree Statics ***********");
int minModels = int.MaxValue;
int maxModels = int.MinValue;
obtenerEstadisticas(rootNode, ref minModels, ref maxModels);
Console.WriteLine("Minima cantidad de modelos en hoja: " + minModels);
Console.WriteLine("Maxima cantidad de modelos en hoja: " + maxModels);
Console.WriteLine("*********** FIN Octree Statics ************");
}
/// <summary>
/// Corte de plano Z
/// </summary>
private void doSectorOctreeZ(OctreeNode parent, Vector3 center, Vector3 size, int step,
List<TgcMesh> meshes, int childIndex)
{
float z = center.Z;
//Crear listas para realizar corte
List<TgcMesh> possitiveList = new List<TgcMesh>();
List<TgcMesh> negativeList = new List<TgcMesh>();
//Z-cut
Plane zCutPlane = new Plane(0, 0, 1, -z);
splitByPlane(zCutPlane, meshes, possitiveList, negativeList);
//obtener lista de children del parent, con iniciacion lazy
if (parent.children == null)
{
parent.children = new OctreeNode[8];
}
//crear nodo positivo en parent, segun childIndex
OctreeNode posNode = new OctreeNode();
parent.children[childIndex] = posNode;
//cargar nodo negativo en parent, segun childIndex
OctreeNode negNode = new OctreeNode();
parent.children[childIndex + 1] = negNode;
//condicion de corte
if (step >= MAX_SECTOR_OCTREE_RECURSION || meshes.Count <= MIN_MESH_PER_LEAVE_THRESHOLD)
{
//cargar hijos de nodo positivo
posNode.models = possitiveList.ToArray();
//cargar hijos de nodo negativo
negNode.models = negativeList.ToArray();
//seguir recursividad
}
else
{
step++;
//recursividad de positivos con plano X, usando resultados positivos
doSectorOctreeX(posNode, new Vector3(center.X, center.Y, z + size.Z / 2),
new Vector3(size.X, size.Y, size.Z / 2),
step, possitiveList);
//recursividad de negativos con plano Y, usando resultados negativos
doSectorOctreeX(negNode, new Vector3(center.X, center.Y, z - size.Z / 2),
new Vector3(size.X, size.Y, size.Z / 2),
step, negativeList);
}
}
/// <summary>
/// Imprime por consola la generacion del Octree
/// </summary>
private void printDebugOctree(OctreeNode rootNode)
{
Console.WriteLine("########## Octree DEBUG ##########");
StringBuilder sb = new StringBuilder();
doPrintDebugOctree(rootNode, 0, sb);
Console.WriteLine(sb.ToString());
Console.WriteLine("########## FIN Octree DEBUG ##########");
}
/// <summary>
/// Cantidad de meshes que tiene un nodo, contando todos los de sus hijos recursivamente
/// </summary>
private int getTotalNodeMeshCount(OctreeNode node)
{
if (node.children == null)
{
return node.models.Length;
}
int meshCount = 0;
for (int i = 0; i < node.children.Length; i++)
{
meshCount += getTotalNodeMeshCount(node.children[i]);
}
return meshCount;
}
/// <summary>
/// Se quitan nodos cuyos hijos siguen teniendo la misma cantidad de modelos que el padre
/// </summary>
private void deleteSameMeshCountChilds(OctreeNode node)
{
if (node == null || node.children == null)
{
return;
}
int nodeCount = getTotalNodeMeshCount(node);
for (int i = 0; i < node.children.Length; i++)
{
OctreeNode childNode = node.children[i];
int childCount = getTotalNodeMeshCount(childNode);
if (childCount == nodeCount)
{
node.children[i] = null;
}
else
{
deleteSameMeshCountChilds(node.children[i]);
}
}
}
/// <summary>
/// Se fija si los hijos de un nodo no tienen mas hijos y no tienen ningun triangulo
/// </summary>
private bool hasEmptyChilds(OctreeNode node)
{
OctreeNode[] children = node.children;
for (int i = 0; i < children.Length; i++)
{
OctreeNode childNode = children[i];
if (childNode.children != null || childNode.models.Length > 0)
{
return false;
}
}
return true;
}
/// <summary>
/// Se quitan padres cuyos nodos no tengan ningun triangulo
/// </summary>
private void deleteEmptyNodes(OctreeNode[] children)
{
if (children == null)
{
return;
}
for (int i = 0; i < children.Length; i++)
{
OctreeNode childNode = children[i];
OctreeNode[] childNodeChildren = childNode.children;
if (childNodeChildren != null && hasEmptyChilds(childNode))
{
childNode.children = null;
childNode.models = new TgcMesh[0];
}
else
{
deleteEmptyNodes(childNodeChildren);
}
}
}
/// <summary>
/// Hacer visibles todas las meshes de un nodo, buscando recursivamente sus hojas
/// </summary>
private void addAllLeafMeshes(OctreeNode node) {
if (node == null)
{
return;
}
OctreeNode[] children = node.children;
//es hoja, cargar todos los meshes
if( children == null )
{
selectLeafMeshes(node);
//pedir hojas a hijos
}
else
{
for (int i = 0; i < children.Length; i++)
{
addAllLeafMeshes(children[i]);
}
}
}
/// <summary>
/// Hacer visibles todas las meshes de un nodo
/// </summary>
private void selectLeafMeshes(OctreeNode node)
{
TgcMesh[] models = node.models;
foreach (TgcMesh m in models)
{
m.Enabled = true;
}
}
/// <summary>
/// Impresion recursiva
/// </summary>
private void doPrintDebugOctree(OctreeNode node, int index, StringBuilder sb)
{
if (node == null)
{
return;
}
String lineas = "";
for (int i = 0; i < index; i++)
{
lineas += "-";
}
if (node.isLeaf())
{
if (node.models.Length > 0)
{
sb.Append(lineas + "Models [" + node.models.Length + "]" + "\n");
}
else
{
sb.Append(lineas + "[0]" + "\n");
}
}
else
{
sb.Append(lineas + "\n");
index++;
for (int i = 0; i < node.children.Length; i++)
{
doPrintDebugOctree(node.children[i], index, sb);
}
}
}
/// <summary>
/// Recorrer recursivamente el Octree para encontrar los nodos visibles
/// </summary>
private void findVisibleMeshes(TgcFrustum frustum, OctreeNode node,
float boxLowerX, float boxLowerY, float boxLowerZ,
float boxUpperX, float boxUpperY, float boxUpperZ)
{
OctreeNode[] children = node.children;
//es hoja, cargar todos los meshes
if (children == null)
{
selectLeafMeshes(node);
}
//recursividad sobre hijos
else
{
float midX = FastMath.Abs((boxUpperX - boxLowerX) / 2);
float midY = FastMath.Abs((boxUpperY - boxLowerY) / 2);
float midZ = FastMath.Abs((boxUpperZ - boxLowerZ) / 2);
//000
testChildVisibility(frustum, children[0], boxLowerX + midX, boxLowerY + midY, boxLowerZ + midZ, boxUpperX, boxUpperY, boxUpperZ);
//001
testChildVisibility(frustum, children[1], boxLowerX + midX, boxLowerY + midY, boxLowerZ, boxUpperX, boxUpperY, boxUpperZ - midZ);
//010
testChildVisibility(frustum, children[2], boxLowerX + midX, boxLowerY, boxLowerZ + midZ, boxUpperX, boxUpperY - midY, boxUpperZ);
//011
testChildVisibility(frustum, children[3], boxLowerX + midX, boxLowerY, boxLowerZ, boxUpperX, boxUpperY - midY, boxUpperZ - midZ);
//100
testChildVisibility(frustum, children[4], boxLowerX, boxLowerY + midY, boxLowerZ + midZ, boxUpperX - midX, boxUpperY, boxUpperZ);
//101
testChildVisibility(frustum, children[5], boxLowerX, boxLowerY + midY, boxLowerZ, boxUpperX - midX, boxUpperY, boxUpperZ - midZ);
//110
testChildVisibility(frustum, children[6], boxLowerX, boxLowerY, boxLowerZ + midZ, boxUpperX - midX, boxUpperY - midY, boxUpperZ);
//111
testChildVisibility(frustum, children[7], boxLowerX, boxLowerY, boxLowerZ, boxUpperX - midX, boxUpperY - midY, boxUpperZ - midZ);
}
}
private void doCreateOctreeDebugBox(OctreeNode node, List<TgcDebugBox> debugBoxes,
float boxLowerX, float boxLowerY, float boxLowerZ,
float boxUpperX, float boxUpperY, float boxUpperZ, int step)
{
if (node == null)
{
return;
}
OctreeNode[] children = node.children;
float midX = FastMath.Abs((boxUpperX - boxLowerX) / 2);
float midY = FastMath.Abs((boxUpperY - boxLowerY) / 2);
float midZ = FastMath.Abs((boxUpperZ - boxLowerZ) / 2);
//Crear caja debug
TgcDebugBox box = createDebugBox(boxLowerX, boxLowerY, boxLowerZ, boxUpperX, boxUpperY, boxUpperZ, step);
debugBoxes.Add(box);
//es hoja, dibujar caja
if (children == null)
{
}
//recursividad sobre hijos
else
{
step++;
//000
doCreateOctreeDebugBox(children[0], debugBoxes, boxLowerX + midX, boxLowerY + midY, boxLowerZ + midZ, boxUpperX, boxUpperY, boxUpperZ, step);
//001
doCreateOctreeDebugBox(children[1], debugBoxes, boxLowerX + midX, boxLowerY + midY, boxLowerZ, boxUpperX, boxUpperY, boxUpperZ - midZ, step);
//010
doCreateOctreeDebugBox(children[2], debugBoxes, boxLowerX + midX, boxLowerY, boxLowerZ + midZ, boxUpperX, boxUpperY - midY, boxUpperZ, step);
//011
doCreateOctreeDebugBox(children[3], debugBoxes, boxLowerX + midX, boxLowerY, boxLowerZ, boxUpperX, boxUpperY - midY, boxUpperZ - midZ, step);
//100
doCreateOctreeDebugBox(children[4], debugBoxes, boxLowerX, boxLowerY + midY, boxLowerZ + midZ, boxUpperX - midX, boxUpperY, boxUpperZ, step);
//101
doCreateOctreeDebugBox(children[5], debugBoxes, boxLowerX, boxLowerY + midY, boxLowerZ, boxUpperX - midX, boxUpperY, boxUpperZ - midZ, step);
//110
doCreateOctreeDebugBox(children[6], debugBoxes, boxLowerX, boxLowerY, boxLowerZ + midZ, boxUpperX - midX, boxUpperY - midY, boxUpperZ, step);
//111
doCreateOctreeDebugBox(children[7], debugBoxes, boxLowerX, boxLowerY, boxLowerZ, boxUpperX - midX, boxUpperY - midY, boxUpperZ - midZ, step);
}
}
