Basic implementation of kdtree generation based on vertices
This commit is contained in:
Robert Osfield
parent
abfb5bbb8d
commit
a9b1ea660d
@ -16,6 +16,11 @@
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* THE SOFTWARE.
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*/
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#include <osgDB/ReadFile>
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#define _GLIBCXX_DEBUG
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#include <osg/ArgumentParser>
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#include <osg/ApplicationUsage>
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#include <osg/Timer>
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@ -24,7 +29,6 @@
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#include <osg/io_utils>
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#include <osg/Geometry>
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#include <osgDB/ReadFile>
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#include <osgUtil/IntersectionVisitor>
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#include <osgUtil/LineSegmentIntersector>
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@ -35,6 +39,7 @@
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#include <iostream>
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namespace osg
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{
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@ -42,7 +47,22 @@ class KDNode
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{
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public:
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typedef short value_type;
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KDNode():
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_leftChild(0),
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_rightChild(0) {}
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KDNode(const KDNode& rhs):
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_leftChild(rhs._leftChild),
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_rightChild(rhs._rightChild) {}
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KDNode& operator = (const KDNode& rhs)
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{
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_leftChild = rhs._leftChild;
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_rightChild = rhs._rightChild;
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return *this;
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}
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typedef int value_type;
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value_type _leftChild;
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value_type _rightChild;
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@ -52,7 +72,7 @@ class KDLeaf : public osg::Referenced
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{
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public:
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KDLeaf();
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KDLeaf() {}
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typedef unsigned int index_type;
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typedef std::vector< index_type > Indices;
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@ -79,6 +99,54 @@ class KDTree : public osg::Shape
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typedef std::vector< unsigned int > AxisStack;
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typedef std::vector< KDNode > KDNodeList;
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typedef std::vector< osg::ref_ptr<KDLeaf> > KDLeafList;
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/// note, leafNum is negative to distinguish from nodeNum
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int addLeaf(KDLeaf* leaf) { int num = _kdLeaves.size(); _kdLeaves.push_back(leaf); return -(num+1); }
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int replaceLeaf(int leafNum, KDLeaf* leaf)
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{
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int num = -leafNum-1;
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if (num>_kdLeaves.size()-1)
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{
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osg::notify(osg::NOTICE)<<"Warning: replaceChild("<<leafNum<<", leaf), num = "<<num<<" _kdLeaves.size()="<<_kdLeaves.size()<<std::endl;
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return leafNum;
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}
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_kdLeaves[num] = leaf; return leafNum;
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}
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/// note, leafNum is negative to distinguish from nodeNum
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KDLeaf* getLeaf(int leafNum)
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{
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int num = -leafNum-1;
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if (num<0 || num>_kdLeaves.size()-1)
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{
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osg::notify(osg::NOTICE)<<"Warning: getLeaf("<<leafNum<<", num = "<<num<<") _kdLeaves.size()="<<_kdLeaves.size()<<std::endl;
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return 0;
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}
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return _kdLeaves[num].get();
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}
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int addNode(const KDNode& node)
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{
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int num = _kdNodes.size();
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_kdNodes.push_back(node);
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return num;
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}
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/// note, nodeNum is positive to distinguish from leftNum
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KDNode& getNode(int nodeNum)
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{
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if (nodeNum<0 || nodeNum>_kdNodes.size()-1)
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{
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osg::notify(osg::NOTICE)<<"Warning: getNode("<<nodeNum<<") _kdNodes.size()="<<_kdNodes.size()<<std::endl;
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}
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return _kdNodes[nodeNum];
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}
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osg::observer_ptr<osg::Geometry> _geometry;
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@ -93,38 +161,66 @@ class KDTreeTraverser
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{
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public:
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void traverse(KDTree& tree, KDNode::value_type nodeIndex, unsigned int level)
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std::ostream& output(unsigned int level)
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{
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for(unsigned int i=0; i<level; ++i)
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{
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osg::notify(osg::NOTICE)<<" ";
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}
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osg::notify(osg::NOTICE)<<"traverse("<<nodeIndex<<", "<< level<<") { "<<std::endl;
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return osg::notify(osg::NOTICE);
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}
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void traverse(KDLeaf& leaf, unsigned int level)
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{
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output(level)<<"leaf("<<level<<") { ";
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for(unsigned int i=0; i<leaf._vertexIndices.size(); ++i)
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{
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if (i==0) osg::notify(osg::NOTICE)<<leaf._vertexIndices[i];
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else osg::notify(osg::NOTICE)<<", "<<leaf._vertexIndices[i];
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}
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osg::notify(osg::NOTICE)<<"}"<<std::endl;;
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}
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void traverse(KDTree& tree, KDNode::value_type nodeIndex, unsigned int level)
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{
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output(level)<<"traverse("<<nodeIndex<<", "<< level<<") { "<<std::endl;
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if (nodeIndex>=0)
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{
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KDNode& node = tree._kdNodes[nodeIndex];
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traverse(tree,node._leftChild,level+1);
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traverse(tree,node._rightChild,level+1);
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if (node._leftChild) traverse(tree,node._leftChild,level+1);
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else output(level+1)<<"empty left child()"<<std::endl;
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if (node._rightChild) traverse(tree,node._rightChild,level+1);
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else output(level+1)<<"empty right child()"<<std::endl;
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}
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else
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{
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KDNode::value_type leafIndex = -nodeIndex-1;
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KDLeaf& leaf = *(tree._kdLeaves[leafIndex]);
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traverse(leaf, level);
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}
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for(unsigned int i=0; i<level; ++i)
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{
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osg::notify(osg::NOTICE)<<" ";
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}
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osg::notify(osg::NOTICE)<<"}"<<std::endl;;
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output(level)<<"}"<<std::endl;;
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}
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void traverse(KDTree& tree)
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{
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osg::notify(osg::NOTICE)<<"traverse(tree)"<<std::endl;
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if (!tree._kdNodes.empty()) traverse(tree,0,0);
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if (!tree._kdNodes.empty())
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{
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traverse(tree,0,0);
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}
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else if (!tree._kdLeaves.empty())
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{
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traverse(*tree._kdLeaves.front(), 0);
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}
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}
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};
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@ -135,7 +231,11 @@ class KDTreeBuilder : public osg::NodeVisitor
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public:
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KDTreeBuilder():
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osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN) {}
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osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
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_maxNumLevels(24),
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_targetNumVerticesPerLeaf(8)
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{
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}
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void apply(osg::Geode& geode)
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@ -151,20 +251,200 @@ class KDTreeBuilder : public osg::NodeVisitor
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}
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KDTree* createKDTree(osg::Geometry* geometry);
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void computeDivisions(KDTree& kdTree);
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int divide(KDTree& kdTree, osg::BoundingBox& bb, int nodeIndex, unsigned int level);
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unsigned int _maxNumLevels;
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unsigned int _targetNumVerticesPerLeaf;
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};
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KDTree* KDTreeBuilder::createKDTree(osg::Geometry* geometry)
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{
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KDTree* kdTree = new KDTree;
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osg::notify(osg::NOTICE)<<"osg::KDTreeBuilder::createKDTree()"<<std::endl;
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osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(geometry->getVertexArray());
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if (!vertices) return 0;
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osg::ref_ptr<KDTree> kdTree = new KDTree;
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kdTree->_geometry = geometry;
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kdTree->_bb = kdTree->_geometry->getBound();
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osg::notify(osg::NOTICE)<<"osg::KDTreeBuilder::createKDTree()"<<std::endl;
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return kdTree;
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unsigned int estimatedSize = (unsigned int)(float(vertices->size())/float(_targetNumVerticesPerLeaf)*1.5);
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osg::notify(osg::NOTICE)<<"kdTree->_kdNodes.reserve()="<<estimatedSize<<std::endl<<std::endl;
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kdTree->_kdNodes.reserve(estimatedSize);
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kdTree->_kdLeaves.reserve(estimatedSize);
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computeDivisions(*kdTree);
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// create initial leaf list
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osg::ref_ptr<KDLeaf> leaf = new KDLeaf;
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leaf->_vertexIndices.reserve(vertices->size());
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for(unsigned int i=0; i<vertices->size(); ++i)
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{
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leaf->_vertexIndices.push_back(i);
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}
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osg::BoundingBox bb = kdTree->_bb;
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int leafNum = kdTree->addLeaf(leaf.get());
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int nodeNum = divide(*kdTree, bb, leafNum, 0);
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osg::notify(osg::NOTICE)<<"Root nodeNum="<<nodeNum<<std::endl;
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KDTreeTraverser traverser;
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traverser.traverse(*kdTree);
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osg::notify(osg::NOTICE)<<"Final kdTree->_kdNodes.size()="<<kdTree->_kdNodes.size()<<std::endl;
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osg::notify(osg::NOTICE)<<"Final kdTree->_kdLeaves.size()="<<kdTree->_kdLeaves.size()<<std::endl;
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osg::notify(osg::NOTICE)<<"osg::KDTreeBuilder::createKDTree() completed"<<std::endl<<std::endl;
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return kdTree.release();
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}
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void KDTreeBuilder::computeDivisions(KDTree& kdTree)
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{
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osg::Vec3 dimensions(kdTree._bb.xMax()-kdTree._bb.xMin(),
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kdTree._bb.yMax()-kdTree._bb.yMin(),
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kdTree._bb.zMax()-kdTree._bb.zMin());
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osg::notify(osg::NOTICE)<<"computeDivisions("<<_maxNumLevels<<") "<<dimensions<< " { "<<std::endl;
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kdTree._axisStack.reserve(_maxNumLevels);
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int level = 0;
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for(unsigned int level=0; level<_maxNumLevels; ++level)
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{
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int axis = 0;
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if (dimensions[0]>=dimensions[1])
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{
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if (dimensions[0]>=dimensions[2]) axis = 0;
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else axis = 2;
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}
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else if (dimensions[1]>=dimensions[2]) axis = 1;
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else axis = 2;
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kdTree._axisStack.push_back(axis);
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dimensions[axis] /= 2.0f;
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osg::notify(osg::NOTICE)<<" "<<level<<", "<<dimensions<<", "<<axis<<std::endl;
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}
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osg::notify(osg::NOTICE)<<"}"<<std::endl;
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}
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int KDTreeBuilder::divide(KDTree& kdTree, osg::BoundingBox& bb, int nodeIndex, unsigned int level)
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{
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if (kdTree._axisStack.size()<=level) return nodeIndex;
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int axis = kdTree._axisStack[level];
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osg::notify(osg::NOTICE)<<"divide("<<nodeIndex<<", "<<level<< "), axis="<<axis<<std::endl;
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if (nodeIndex>=0)
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{
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osg::notify(osg::NOTICE)<<" divide node"<<std::endl;
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KDNode& node = kdTree.getNode(nodeIndex);
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return nodeIndex;
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}
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else
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{
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if (kdTree.getLeaf(nodeIndex)->_vertexIndices.size()<=_targetNumVerticesPerLeaf) return nodeIndex;
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osg::notify(osg::NOTICE)<<" divide leaf"<<std::endl;
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int nodeNum = kdTree.addNode(KDNode());
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float original_min = bb._min[axis];
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float original_max = bb._max[axis];
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float mid = (original_min+original_max)*0.5f;
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{
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osg::ref_ptr<KDLeaf> leaf = kdTree.getLeaf(nodeIndex);
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// create new node, and add two leaves to it.
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osg::ref_ptr<KDLeaf> leftLeaf = new KDLeaf;
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osg::ref_ptr<KDLeaf> rightLeaf = new KDLeaf;
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osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(kdTree._geometry->getVertexArray());
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osg::notify(osg::NOTICE)<<" divide leaf->_vertexIndices.size()="<<leaf->_vertexIndices.size()<<std::endl;
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unsigned int estimatedSize = leaf->_vertexIndices.size();
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leftLeaf->_vertexIndices.reserve(estimatedSize);
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rightLeaf->_vertexIndices.reserve(estimatedSize);
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for(unsigned int i=0; i<leaf->_vertexIndices.size(); ++i)
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{
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unsigned int vi = leaf->_vertexIndices[i];
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osg::Vec3& v = (*vertices)[vi];
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if (v[axis] <= mid) leftLeaf->_vertexIndices.push_back(vi);
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else rightLeaf->_vertexIndices.push_back(vi);
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}
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if (leftLeaf->_vertexIndices.empty())
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{
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osg::notify(osg::NOTICE)<<"LeftLeaf empty"<<std::endl;
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kdTree.getNode(nodeNum)._leftChild = 0;
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kdTree.getNode(nodeNum)._rightChild = kdTree.replaceLeaf(nodeIndex, rightLeaf.get());
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}
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else if (rightLeaf->_vertexIndices.empty())
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{
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osg::notify(osg::NOTICE)<<"RightLeaf empty"<<std::endl;
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kdTree.getNode(nodeNum)._leftChild = kdTree.replaceLeaf(nodeIndex, leftLeaf.get());
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kdTree.getNode(nodeNum)._rightChild = 0;
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}
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else
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{
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kdTree.getNode(nodeNum)._leftChild = kdTree.replaceLeaf(nodeIndex, leftLeaf.get());
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kdTree.getNode(nodeNum)._rightChild = kdTree.addLeaf(rightLeaf.get());
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}
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}
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int originalLeftChildIndex = kdTree.getNode(nodeNum)._leftChild;
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int originalRightChildIndex = kdTree.getNode(nodeNum)._rightChild;
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float restore = bb._max[axis];
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bb._max[axis] = mid;
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osg::notify(osg::NOTICE)<<" divide leftLeaf "<<kdTree.getNode(nodeNum)._leftChild<<std::endl;
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int leftChildIndex = divide(kdTree, bb, originalLeftChildIndex, level+1);
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bb._max[axis] = restore;
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restore = bb._min[axis];
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bb._min[axis] = mid;
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osg::notify(osg::NOTICE)<<" divide rightLeaf "<<kdTree.getNode(nodeNum)._rightChild<<std::endl;
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int rightChildIndex = divide(kdTree, bb, originalRightChildIndex, level+1);
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bb._min[axis] = restore;
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kdTree.getNode(nodeNum)._leftChild = leftChildIndex;
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kdTree.getNode(nodeNum)._rightChild = rightChildIndex;
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return nodeNum;
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}
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}
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}
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int main(int argc, char **argv)
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