/**************************************************************************** * VCGLib o o * * Visual and Computer Graphics Library o o * * _ O _ * * Copyright(C) 2004 \/)\/ * * Visual Computing Lab /\/| * * ISTI - Italian National Research Council | * * \ * * All rights reserved. * * * * This program is free software; you can redistribute it and/or modify * * it under the terms of the GNU General Public License as published by * * the Free Software Foundation; either version 2 of the License, or * * (at your option) any later version. * * * * This program is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * * GNU General Public License (http://www.gnu.org/licenses/gpl.txt) * * for more details. * * * ****************************************************************************/ #ifndef VCG_SPACE_INDEX_OCTREETEMPLATE_H #define VCG_SPACE_INDEX_OCTREETEMPLATE_H #include #include #include namespace vcg { /* Octree Template Tiene un dataset volumetrico come un octree Assunzione che la grandezza sia una potenza di due La prof max e' fissa. E' un octree in cui il dato e' nella cella dell'octree. Anche i nodi non foglia hanno il dato Voxel Assunzioni sul tipo voxel: che abbia definiti gli operatori per poterci fare sopra pushpull. Si tiene int invece di puntatori per garantirsi reallocazione dinamica. I dati veri e propri stanno in un vettore di nodi */ template class OctreeTemplate { protected: struct Node; public: // Octree Type Definitions typedef unsigned long long ZOrderType; typedef SCALAR_TYPE ScalarType; typedef VOXEL_TYPE VoxelType; typedef VoxelType * VoxelPointer; typedef vcg::Point3i CenterType; static const ScalarType EXPANSION_FACTOR; typedef Node NodeType; typedef int NodeIndex; typedef NodeType * NodePointer; typedef vcg::Box3 BoundingBoxType; typedef vcg::Point3 CoordinateType; protected: /* * Inner structures: * Contains the information related to the octree node */ struct Node { // Default constructor: fill the data members with non-meaningful values Node() { parent = NULL; level = -1; } // Constructor: create a new Node Node(NodePointer parent, int level) { this->parent = parent; this->level = (char) level; } inline virtual NodePointer &Son(int sonIndex) = 0; inline virtual bool IsLeaf() = 0; // The position of the center of the node in integer coords in the 0..2^(2*sz) -1 range // The root has position (lsz/2,lsz/2,lsz/2) CenterType center; char level; NodePointer parent; VoxelType voxel; }; /* * Inner struct: Node */ struct InnerNode : public Node { InnerNode() : Node() {}; InnerNode(NodePointer parent, int level) : Node(parent, level) { memset(&sons[0], 0, 8*sizeof(Node*)); } inline NodePointer &Son(int sonIndex) { assert(0<=sonIndex && sonIndex<=8); return sons[sonIndex]; } inline bool IsLeaf() { return false; } NodePointer sons[8]; }; /* * Inner struct: Leaf */ struct Leaf : public Node { Leaf() : Node() {}; Leaf(NodePointer parent, int level) : Node(parent, level) {} inline NodePointer &Son(int /*sonIndex*/) { assert(false); static NodePointer p = NULL; return p; } inline bool IsLeaf() { return true; } }; public: // Inizializza l'octree void Initialize(int maximumDepth) { this->maximumDepth = maximumDepth; size = 1<< maximumDepth; // e.g. 1*2^maxDepth lSize = 1<<(maximumDepth+1); // e.g. 1*2^(maxDepth+1) InnerNode *root = new InnerNode(NULL,0); nodes.clear(); nodes.push_back( root ); root->center = CenterType(size, size, size); ScalarType szf = (ScalarType) size; leafDimension = boundingBox.Dim(); leafDimension /= szf; leafDiagonal = leafDimension.Norm(); }; // Return the octree bounding-box inline BoundingBoxType BoundingBox() { return boundingBox; } // Return the Voxel of the n-th node inline VoxelPointer Voxel(const NodePointer n) { return &(n->voxel); } // Return the octree node count inline int NodeCount() const { return int(nodes.size()); } // Return the root index inline const NodePointer Root() const { return nodes[0]; } // Return the level of the n-th node inline char Level(const NodePointer n) const { return n->level; } // Return the referente to the i-th son of the n-th node inline NodePointer& Son(NodePointer n, int i) const { return n->Son(i); } // Return the parent index of the n-th node inline NodePointer Parent(const NodePointer n) const { return n->parent; } // Return the index of the current node in its father int WhatSon(NodePointer n) const { if(n==Root()) assert(false); NodePointer parent = Parent(n); for(int i=0;i<8;++i) if(parent->Son(i)==n) return i; return -1; } // Return the center of the n-th node inline CenterType CenterInOctreeCoordinates(const NodePointer n) const { return n->center;} /*! * Return the center of the n-th node expressed in world-coordinate * \param NodePointer the pointer to the node whose center in world coordinate has to be computed */ inline void CenterInWorldCoordinates(const NodePointer n, CoordinateType &wc_Center) const { assert(0<=n && n>shift))); wc_Center.Y() = boundingBox.min.Y() + (nodeSize.Y()*(0.5f+(ocCenter.Y()>>shift))); wc_Center.Z() = boundingBox.min.Z() + (nodeSize.Z()*(0.5f+(ocCenter.Z()>>shift))); }; // Given a node (even not leaf) it returns the center of the box it represent. // the center is expressed not in world-coordinates. // e.g. the root is (sz/2,sz/2,sz/2); // and the finest element in the grid in lower left corner has center (.5, .5, .5) /* 4---------------- 4---------------- 4---------------- | | | | | | | | | | 3---+---+---+---| 3 | | 3 | | | | | | | | | | | 2---+---+---+---| 2---+---+---+---| 2 c | | | | | | | | | | | 1---+---+---+---| 1 b + | 1 | | a | | | | | | | | | 0---1---2---3---4 0---1---2---3---4 0---1---2---3---4 This is a tree with maxdepth==2, so sz is 2^2=4 a) a leaf at the deepest level 2 has position (.5,.5) b) a mid node (lev 1) has position (1,1) c) root has level 0 and position (sz/2,sz/2) = (2,2) The center of a node has integer coords in the 2^(MaxDepth+1) range. The other approach is to use position as a bit string codifying the tree path, but in this case you have to supply also the level (e.g. the string lenght) you desire. The lower left corner node is always 0 ( (,) for the root (0,0) level 1, and (00,00) for level 2) | ~~~ | | 0~~ | 1~~ | | 00~ | 01~ | 10~ | 11~ | |000|001|010|011|100|101|110|111| The interesting properties is that if your octree represent a space [minv,maxv] and you want to find the octree cell containing a point p in [minv,maxv] you just have to convert p in the range [0,sz) truncate it to an integer and use it as a path. For example, consider an octree of depth 3, representing a range [0..100) sz=8 (each cell contains form 0 to 12.5 the point 5 -> 0.4 -> path is 000 45 -> 3.6 -> path is 011 50 -> 4.0 -> path is 100 100 -> 8 -> ERROR the interval is right open!!! Note how each cell is meant to contains a right open interval (e.g. the first cell contains [0,12.5) and the second [12.5,25) and so on) The center of each cell can simply be obtained by adding .5 to the path of the leaves. */ CoordinateType Center(NodePointer n) const { CoordinateType center; center.Import(GetPath(n)); center+=Point3f(.5f,.5f,.5f); //TODO verify the assert assert(center==nodes[n]->center); return center; } // Return the bounding-box of the n-th node expressed in world-coordinate BoundingBoxType BoundingBoxInWorldCoordinates(const NodePointer n) { char level = Level(n); int shift = maximumDepth-level+1; CoordinateType nodeDim = boundingBox.Dim()/float(1<>shift)); nodeBB.min.Y() = boundingBox.min.Y() + (nodeDim.Y()*(center.Y()>>shift)); nodeBB.min.Z() = boundingBox.min.Z() + (nodeDim.Z()*(center.Z()>>shift)); nodeBB.max = nodeBB.min+nodeDim; return nodeBB; }; /*! * Return the bounding-box of a node expressed in world-coordinate * \param NodePointer the node whose bounding-box has to be computed * \param wc_BB the bounding-box of the node in world coordinta */ inline void BoundingBoxInWorldCoordinates(const NodePointer n, BoundingBoxType &wc_bb) const { char level = Level(n); int shift = maximumDepth - level + 1; CoordinateType node_dimension = boundingBox.Dim()/ScalarType(1<center.X()>>shift)); wc_bb.min.Y() = boundingBox.min.Y()+(node_dimension.Y()*(n->center.Y()>>shift)); wc_bb.min.Z() = boundingBox.min.Z()+(node_dimension.Z()*(n->center.Z()>>shift)); wc_bb.max = wc_bb.min+node_dimension; }; // Return one of the 8 subb box of a given box. BoundingBoxType SubBox(BoundingBoxType &lbb, int i) { BoundingBoxType bs; if (i&1) bs.min.X()=(lbb.min.X()+(bs.max.X()=lbb.max.X()))/2.0f; else bs.max.X()=((bs.min.X()=lbb.min.X())+lbb.max.X())/2.0f; if (i&2) bs.min.Y()=(lbb.min.Y()+(bs.max.Y()=lbb.max.Y()))/2.0f; else bs.max.Y()=((bs.min.Y()=lbb.min.Y())+lbb.max.Y())/2.0f; if (i&4) bs.min.Z()=(lbb.min.Z()+(bs.max.Z()=lbb.max.Z()))/2.0f; else bs.max.Z()=((bs.min.Z()=lbb.min.Z())+lbb.max.Z())/2.0f; return bs; } // Given the bounding-box and the center (both in world-coordinates) // of a node, return the bounding-box (in world-coordinats) of the i-th son BoundingBoxType SubBoxAndCenterInWorldCoordinates(BoundingBoxType &lbb, CoordinateType ¢er, int i) { BoundingBoxType bs; if (i&1) { bs.min[0]=center[0]; bs.max[0]=lbb.max[0]; } else { bs.min[0]=lbb.min[0]; bs.max[0]=center[0]; } if (i&2) { bs.min[1]=center[1]; bs.max[1]=lbb.max[1]; } else { bs.max[1]=center[1]; bs.min[1]=lbb.min[1]; } if (i&4) { bs.min[2]=center[2]; bs.max[2]=lbb.max[2]; } else { bs.max[2]=center[2]; bs.min[2]=lbb.min[2]; } return bs; }; /* * Add a new Node to the octree. * The created node is the i-th son of the node pointed to by parent. * Return the pointer to the new node */ NodePointer NewNode(NodePointer parent, int i) { assert(0<=i && i<8); assert(Son(parent, i)==NULL); //int index = NodeCount(); char level = Level(parent)+1; Node *node = (levelcenter); int displacement = 1<<(maximumDepth-level); node->center.X() = parentCenter->X() + ((i&1)? displacement : -displacement); node->center.Y() = parentCenter->Y() + ((i&2)? displacement : -displacement); node->center.Z() = parentCenter->Z() + ((i&4)? displacement : -displacement); return node; } // Aggiunge un nodo all'octree nella posizione specificata e al livello specificato. // Vengono inoltre inseriti tutti gli antenati mancanti per andare dalla radice // al nodo ed al livello specificato seguendo path. NodePointer AddNode(CenterType path) { //the input coordinates must be in the range 0..2^maxdepth assert(path[0]>=0 && path[0]=0 && path[1]=0 && path[2]= rootLevel) { int nextSon=0; if((path[0]>>shiftLevel)%2) nextSon +=1; if((path[1]>>shiftLevel)%2) nextSon +=2; if((path[2]>>shiftLevel)%2) nextSon +=4; NodePointer nextNode = Son(curNode, nextSon); if(nextNode!=NULL) // nessun nodo può aver Root() per figlio curNode = nextNode; else { NodePointer newNode = NewNode(curNode, nextSon); assert(Son(curNode, nextSon)==newNode); // TODO delete an assignment curNode=newNode; } --shiftLevel; } return curNode; } /*! * Given a query point, compute the z_order of the leaf where this point would be contained. * This leaf not necessarily must be exist! */ // Convert the point p coordinates to the integer based representation // in the range 0..size, where size is 2^maxdepth CenterType Interize(const CoordinateType &pf) const { CenterType pi; assert(pf.X()>=boundingBox.min.X() && pf.X()<=boundingBox.max.X()); assert(pf.Y()>=boundingBox.min.Y() && pf.Y()<=boundingBox.max.Y()); assert(pf.Z()>=boundingBox.min.Z() && pf.Z()<=boundingBox.max.Z()); pi.X() = int((pf.X() - boundingBox.min.X()) * size / (boundingBox.max.X() - boundingBox.min.X())); pi.Y() = int((pf.Y() - boundingBox.min.Y()) * size / (boundingBox.max.Y() - boundingBox.min.Y())); pi.Z() = int((pf.Z() - boundingBox.min.Z()) * size / (boundingBox.max.Z() - boundingBox.min.Z())); return pi; } // Inverse function of Interize; // Return to the original coords space (not to the original values!!) CoordinateType DeInterize(const CenterType &pi ) const { CoordinateType pf; assert(pi.X()>=0 && pi.X()=0 && pi.Y()=0 && pi.Z()=0 && path[0]=0 && path[1]=0 && path[2]>shift)%2) son +=1; if((path[1]>>shift)%2) son +=2; if((path[2]>>shift)%2) son +=4; NodePointer nextNode = Son(curNode, son); if(nextNode!=NULL) curNode=nextNode; else break; --shift; } return curNode; } // Return the 'path' from root to the specified node; // the path is coded as a point3s; each bit of each component code the direction in one level // only the last 'level' bits of the returned value are meaningful // for example for the root no bit are meaningfull (path is 0) // for the first level only one bit of each one of the three components are maninguful; CenterType GetPath(NodePointer n) const { if(n==Root()) return CenterType(0,0,0); CenterType path(0,0,0); int shift, mask, son; int startingLevel = int(Level(n)); while (n!=Root()) { shift = startingLevel-Level(n); //nodes[n].level mask = 1 << shift; // e.g. 1*2^shift son = WhatSon(n); if(son&1) path[0] |= mask; if(son&2) path[1] |= mask; if(son&4) path[2] |= mask; n = Parent(n); // nodes[n].parent } return path; } // Dato un punto 3D nello spazio restituisce un array contenente // i puntatori ai nodi che lo contengono, dalla radice fino alle foglie. // I nodi mancanti dalla radice fino a profondità maxDepth vengono aggiunti. // In posizione i ci sarà il nodo di livello i. // Restituisce lo z-order del punto p ZOrderType BuildRoute(const CoordinateType &p, NodePointer *&route) { assert( boundingBox.min.X()<=p.X() && p.X()<=boundingBox.max.X() ); assert( boundingBox.min.Y()<=p.Y() && p.Y()<=boundingBox.max.Y() ); assert( boundingBox.min.Z()<=p.Z() && p.Z()<=boundingBox.max.Z() ); route[0] = Root(); NodePointer curNode = Root(); int shift = maximumDepth-1; CenterType path = CenterType::Construct(Interize(p)); while(shift >= 0) { int son = 0; if((path[0]>>shift)%2) son +=1; if((path[1]>>shift)%2) son +=2; if((path[2]>>shift)%2) son +=4; NodePointer nextNode = Son(curNode, son); if(nextNode!=NULL) { route[maximumDepth-shift] = nextNode; curNode = nextNode; } else { NodePointer newNode = NewNode(curNode, son); route[maximumDepth-shift] = newNode; curNode = newNode; } --shift; } return ZOrder(route[maximumDepth]); }; //end of BuildRoute // Restituisce il percorso dalla radice fino al nodo di profondità // massima presente nell'octree contenente il nodo p. Nessun nuovo nodo è aggiunto // all'octree. In route sono inseriti gli indici dei nodi contenti p, dalla radice // fino al nodo di profontidà massima presente; nelle eventuali posizioni rimaste // libere è inserito il valore -1. Restituisce true se il punto p cade in una foglia // dell'otree, false altrimenti bool GetRoute(const CoordinateType &p, NodePointer *&route) { assert( boundingBox.min.X()<=p.X() && p.X()<=boundingBox.max.X() ); assert( boundingBox.min.Y()<=p.Y() && p.Y()<=boundingBox.max.Y() ); assert( boundingBox.min.Z()<=p.Z() && p.Z()<=boundingBox.max.Z() ); memset(route, NULL, maximumDepth*sizeof(NodePointer)); CenterType path = CenterType::Construct(Interize(p)); int shift = maximumDepth-1; NodePointer finalLevel = Root(); NodePointer curNode = Root(); while(shift >= finalLevel) { int son=0; if((path[0]>>shift)%2) son +=1; if((path[1]>>shift)%2) son +=2; if((path[2]>>shift)%2) son +=4; NodePointer nextNode = Son(curNode, son); if(nextNode!=NULL) { route[maximumDepth-shift] = nextNode; curNode = nextNode; } else return false; --shift; } return true; }; //end of GetReoute // Data una bounding-box bb_query, calcola l'insieme dei nodi di // profondità depth il cui bounding-box ha intersezione non nulla con // bb (la bounding-box dell'octree); i puntatori a tali nodi sono // inseriti progressivamente in contained_nodes. // The vector nodes must be cleared before calling this method. void ContainedNodes ( BoundingBoxType &query, std::vector< NodePointer > &nodes, int depth, NodePointer n, BoundingBoxType &nodeBB) { if (!query.Collide(nodeBB)) return; if (Level(n)==depth) nodes.push_back(n); else { NodePointer son; BoundingBoxType sonBB; CoordinateType nodeCenter = nodeBB.Center(); for (int s=0; s<8; s++) { son = Son(n, s); if (son!=NULL) { sonBB = SubBoxAndCenterInWorldCoordinates(nodeBB, nodeCenter, s); ContainedNodes(query, nodes, depth, son, sonBB); } } } }; //end of ContainedNodes // Data una bounding-box bb, calcola l'insieme delle foglie il cui // bounding-box ha intersezione non nulla con bb; i loro indici // sono inseriti all'interno di leaves. void ContainedLeaves( BoundingBoxType &query, std::vector< NodePointer > &leaves, NodePointer node, BoundingBoxType &nodeBB ) { NodePointer son; BoundingBoxType sonBB; CoordinateType nodeCenter = nodeBB.Center(); for (int s=0; s<8; s++) { son = Son(node, s); //nodes[nodeIndex].sonIndex[s] if (son!=NULL) { sonBB = SubBoxAndCenterInWorldCoordinates(nodeBB, nodeCenter, s); if ( query.Collide(sonBB) ) { if ( son->IsLeaf() ) leaves.push_back(son); else ContainedLeaves(query, leaves, son, sonBB); } } } }; //end of ContainedLeaves /* * Octree Data Members */ public: // the size of the finest grid available (2^maxDepth) int size; // double the size(2^maxDepth) int lSize; // The allowed maximum depth int maximumDepth; // The dimension of a leaf CoordinateType leafDimension; // The diagonal of a leaf ScalarType leafDiagonal; // The Octree nodes std::vector< Node* > nodes; // The bounding box containing the octree (in world coordinate) BoundingBoxType boundingBox; }; //end of class OctreeTemplate template const SCALAR_TYPE OctreeTemplate::EXPANSION_FACTOR = SCALAR_TYPE(0.035); } #endif //VCG_SPACE_INDEX_OCTREETEMPLATE_H