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OpenSceneGraph/src/osg/KdTree.cpp

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/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library 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
* OpenSceneGraph Public License for more details.
*/
#include <osg/KdTree>
#include <osg/Geode>
#include <osg/TriangleIndexFunctor>
#include <osg/TemplatePrimitiveIndexFunctor>
#include <osg/Timer>
#include <osg/io_utils>
using namespace osg;
//#define VERBOSE_OUTPUT
////////////////////////////////////////////////////////////////////////////////
//
// BuildKdTree Declarartion - class used for building an single KdTree
struct BuildKdTree
{
BuildKdTree(KdTree& kdTree):
_kdTree(kdTree) {}
typedef std::vector< osg::Vec3 > CenterList;
typedef std::vector< unsigned int > Indices;
typedef std::vector< unsigned int > AxisStack;
bool build(KdTree::BuildOptions& options, osg::Geometry* geometry);
void computeDivisions(KdTree::BuildOptions& options);
int divide(KdTree::BuildOptions& options, osg::BoundingBox& bb, int nodeIndex, unsigned int level);
KdTree& _kdTree;
osg::BoundingBox _bb;
AxisStack _axisStack;
Indices _primitiveIndices;
CenterList _centers;
protected:
BuildKdTree& operator = (const BuildKdTree&) { return *this; }
};
struct PrimitiveIndicesCollector
{
PrimitiveIndicesCollector():
_buildKdTree(0)
{
}
inline void operator () (unsigned int p0)
{
//OSG_NOTICE<<" point ("<<p0<<")"<<std::endl;
const osg::Vec3& v0 = (*(_buildKdTree->_kdTree.getVertices()))[p0];
_buildKdTree->_kdTree.addPoint(p0);
osg::BoundingBox bb;
bb.expandBy(v0);
_buildKdTree->_primitiveIndices.push_back(_buildKdTree->_centers.size());
_buildKdTree->_centers.push_back(bb.center());
}
inline void operator () (unsigned int p0, unsigned int p1)
{
//OSG_NOTICE<<" line ("<<p0<<", "<<p1<<")"<<std::endl;
const osg::Vec3& v0 = (*(_buildKdTree->_kdTree.getVertices()))[p0];
const osg::Vec3& v1 = (*(_buildKdTree->_kdTree.getVertices()))[p1];
// discard degenerate points
if (v0==v1)
{
//OSG_NOTICE<<"Disgarding degenerate triangle"<<std::endl;
_buildKdTree->_kdTree._degenerateCount++;
return;
}
_buildKdTree->_kdTree.addLine(p0,p1);
osg::BoundingBox bb;
bb.expandBy(v0);
bb.expandBy(v1);
_buildKdTree->_primitiveIndices.push_back(_buildKdTree->_centers.size());
_buildKdTree->_centers.push_back(bb.center());
}
inline void operator () (unsigned int p0, unsigned int p1, unsigned int p2)
{
// OSG_NOTICE<<" triangle ("<<p0<<", "<<p1<<", "<<p2<<")"<<std::endl;
const osg::Vec3& v0 = (*(_buildKdTree->_kdTree.getVertices()))[p0];
const osg::Vec3& v1 = (*(_buildKdTree->_kdTree.getVertices()))[p1];
const osg::Vec3& v2 = (*(_buildKdTree->_kdTree.getVertices()))[p2];
// discard degenerate points
if (v0==v1 || v1==v2 || v2==v0)
{
//OSG_NOTICE<<"Disgarding degenerate triangle"<<std::endl;
_buildKdTree->_kdTree._degenerateCount++;
return;
}
_buildKdTree->_kdTree.addTriangle(p0,p1,p2);
osg::BoundingBox bb;
bb.expandBy(v0);
bb.expandBy(v1);
bb.expandBy(v2);
_buildKdTree->_primitiveIndices.push_back(_buildKdTree->_centers.size());
_buildKdTree->_centers.push_back(bb.center());
}
inline void operator () (unsigned int p0, unsigned int p1, unsigned int p2, unsigned int p3)
{
//OSG_NOTICE<<" quad ("<<p0<<", "<<p1<<", "<<p2<<", "<<p3<<")"<<std::endl;
const osg::Vec3& v0 = (*(_buildKdTree->_kdTree.getVertices()))[p0];
const osg::Vec3& v1 = (*(_buildKdTree->_kdTree.getVertices()))[p1];
const osg::Vec3& v2 = (*(_buildKdTree->_kdTree.getVertices()))[p2];
const osg::Vec3& v3 = (*(_buildKdTree->_kdTree.getVertices()))[p3];
// discard degenerate points
if (v0==v1 || v1==v2 || v2==v0 || v3==v0 || v3==v1 || v3==v2)
{
//OSG_NOTICE<<"Disgarding degenerate quad"<<std::endl;
_buildKdTree->_kdTree._degenerateCount++;
return;
}
_buildKdTree->_kdTree.addQuad(p0,p1,p2,p3);
osg::BoundingBox bb;
bb.expandBy(v0);
bb.expandBy(v1);
bb.expandBy(v2);
bb.expandBy(v3);
_buildKdTree->_primitiveIndices.push_back(_buildKdTree->_centers.size());
_buildKdTree->_centers.push_back(bb.center());
}
BuildKdTree* _buildKdTree;
};
////////////////////////////////////////////////////////////////////////////////
//
// BuildKdTree Implementation
bool BuildKdTree::build(KdTree::BuildOptions& options, osg::Geometry* geometry)
{
#ifdef VERBOSE_OUTPUT
OSG_NOTICE<<"osg::KDTreeBuilder::createKDTree()"<<std::endl;146
#endif
osg::Vec3Array* vertices = dynamic_cast<osg::Vec3Array*>(geometry->getVertexArray());
if (!vertices) return false;
if (vertices->size() <= options._targetNumTrianglesPerLeaf) return false;
_bb = geometry->getBoundingBox();
_kdTree.setVertices(vertices);
unsigned int estimatedSize = (unsigned int)(2.0*float(vertices->size())/float(options._targetNumTrianglesPerLeaf));
#ifdef VERBOSE_OUTPUT
OSG_NOTICE<<"kdTree->_kdNodes.reserve()="<<estimatedSize<<std::endl<<std::endl;
#endif
_kdTree.getNodes().reserve(estimatedSize*5);
computeDivisions(options);
options._numVerticesProcessed += vertices->size();
unsigned int estimatedNumTriangles = vertices->size()*2;
_primitiveIndices.reserve(estimatedNumTriangles);
_centers.reserve(estimatedNumTriangles);
osg::TemplatePrimitiveIndexFunctor<PrimitiveIndicesCollector> collectIndices;
collectIndices._buildKdTree = this;
geometry->accept(collectIndices);
_primitiveIndices.reserve(vertices->size());
KdTree::KdNode node(-1, _primitiveIndices.size());
node.bb = _bb;
int nodeNum = _kdTree.addNode(node);
osg::BoundingBox bb = _bb;
nodeNum = divide(options, bb, nodeNum, 0);
osg::KdTree::Indices& primitiveIndices = _kdTree.getPrimitiveIndices();
KdTree::Indices new_indices;
new_indices.reserve(_primitiveIndices.size());
for(Indices::iterator itr = _primitiveIndices.begin();
itr != _primitiveIndices.end();
++itr)
{
new_indices.push_back(primitiveIndices[*itr]);
}
primitiveIndices.swap(new_indices);
#ifdef VERBOSE_OUTPUT
OSG_NOTICE<<"Root nodeNum="<<nodeNum<<std::endl;
#endif
// OSG_NOTICE<<"_kdNodes.size()="<<k_kdNodes.size()<<" estimated size = "<<estimatedSize<<std::endl;
// OSG_NOTICE<<"_kdLeaves.size()="<<_kdLeaves.size()<<" estimated size = "<<estimatedSize<<std::endl<<std::endl;
return !_kdTree.getNodes().empty();
}
void BuildKdTree::computeDivisions(KdTree::BuildOptions& options)
{
osg::Vec3 dimensions(_bb.xMax()-_bb.xMin(),
_bb.yMax()-_bb.yMin(),
_bb.zMax()-_bb.zMin());
#ifdef VERBOSE_OUTPUT
OSG_NOTICE<<"computeDivisions("<<options._maxNumLevels<<") "<<dimensions<< " { "<<std::endl;
#endif
_axisStack.reserve(options._maxNumLevels);
for(unsigned int level=0; level<options._maxNumLevels; ++level)
{
int axis = 0;
if (dimensions[0]>=dimensions[1])
{
if (dimensions[0]>=dimensions[2]) axis = 0;
else axis = 2;
}
else if (dimensions[1]>=dimensions[2]) axis = 1;
else axis = 2;
_axisStack.push_back(axis);
dimensions[axis] /= 2.0f;
#ifdef VERBOSE_OUTPUT
OSG_NOTICE<<" "<<level<<", "<<dimensions<<", "<<axis<<std::endl;
#endif
}
#ifdef VERBOSE_OUTPUT
OSG_NOTICE<<"}"<<std::endl;
#endif
}
int BuildKdTree::divide(KdTree::BuildOptions& options, osg::BoundingBox& bb, int nodeIndex, unsigned int level)
{
KdTree::KdNode& node = _kdTree.getNode(nodeIndex);
bool needToDivide = level < _axisStack.size() &&
(node.first<0 && static_cast<unsigned int>(node.second)>options._targetNumTrianglesPerLeaf);
if (!needToDivide)
{
if (node.first<0)
{
int istart = -node.first-1;
int iend = istart+node.second-1;
// leaf is done, now compute bound on it.
node.bb.init();
for(int i=istart; i<=iend; ++i)
{
unsigned int primitiveIndex = _kdTree.getPrimitiveIndices()[_primitiveIndices[i]];
primitiveIndex++; //skip original Primitive index
unsigned int numPoints = _kdTree.getVertexIndices()[primitiveIndex++];
for(; numPoints>0; --numPoints)
{
unsigned int vi = _kdTree.getVertexIndices()[primitiveIndex++];
const osg::Vec3& v = (*_kdTree.getVertices())[vi];
node.bb.expandBy(v);
}
}
if (node.bb.valid())
{
float epsilon = 1e-6f;
node.bb._min.x() -= epsilon;
node.bb._min.y() -= epsilon;
node.bb._min.z() -= epsilon;
node.bb._max.x() += epsilon;
node.bb._max.y() += epsilon;
node.bb._max.z() += epsilon;
}
#ifdef VERBOSE_OUTPUT
if (!node.bb.valid())
{
OSG_NOTICE<<"After reset "<<node.first<<","<<node.second<<std::endl;
OSG_NOTICE<<" bb._min ("<<node.bb._min<<")"<<std::endl;
OSG_NOTICE<<" bb._max ("<<node.bb._max<<")"<<std::endl;
}
else
{
OSG_NOTICE<<"Set bb for nodeIndex = "<<nodeIndex<<std::endl;
}
#endif
}
return nodeIndex;
}
int axis = _axisStack[level];
#ifdef VERBOSE_OUTPUT
OSG_NOTICE<<"divide("<<nodeIndex<<", "<<level<< "), axis="<<axis<<std::endl;
#endif
if (node.first<0)
{
// leaf node as first <= 0, so look at dividing it.
int istart = -node.first-1;
int iend = istart+node.second-1;
//OSG_NOTICE<<" divide leaf"<<std::endl;
float original_min = bb._min[axis];
float original_max = bb._max[axis];
float mid = (original_min+original_max)*0.5f;
int originalLeftChildIndex = 0;
int originalRightChildIndex = 0;
bool insitueDivision = false;
{
//osg::Vec3Array* vertices = kdTree._vertices.get();
int left = istart;
int right = iend;
while(left<right)
{
while(left<right && (_centers[_primitiveIndices[left]][axis]<=mid)) { ++left; }
while(left<right && (_centers[_primitiveIndices[right]][axis]>mid)) { --right; }
if (left<right)
{
std::swap(_primitiveIndices[left], _primitiveIndices[right]);
++left;
--right;
}
}
if (left==right)
{
if (_centers[_primitiveIndices[left]][axis]<=mid) ++left;
else --right;
}
KdTree::KdNode leftLeaf(-istart-1, (right-istart)+1);
KdTree::KdNode rightLeaf(-left-1, (iend-left)+1);
if (leftLeaf.second<=0)
{
//OSG_NOTICE<<"LeftLeaf empty"<<std::endl;
originalLeftChildIndex = 0;
//originalRightChildIndex = addNode(rightLeaf);
originalRightChildIndex = nodeIndex;
insitueDivision = true;
}
else if (rightLeaf.second<=0)
{
//OSG_NOTICE<<"RightLeaf empty"<<std::endl;
// originalLeftChildIndex = addNode(leftLeaf);
originalLeftChildIndex = nodeIndex;
originalRightChildIndex = 0;
insitueDivision = true;
}
else
{
originalLeftChildIndex = _kdTree.addNode(leftLeaf);
originalRightChildIndex = _kdTree.addNode(rightLeaf);
}
}
float restore = bb._max[axis];
bb._max[axis] = mid;
//OSG_NOTICE<<" divide leftLeaf "<<kdTree.getNode(nodeNum).first<<std::endl;
int leftChildIndex = originalLeftChildIndex!=0 ? divide(options, bb, originalLeftChildIndex, level+1) : 0;
bb._max[axis] = restore;
restore = bb._min[axis];
bb._min[axis] = mid;
//OSG_NOTICE<<" divide rightLeaf "<<kdTree.getNode(nodeNum).second<<std::endl;
int rightChildIndex = originalRightChildIndex!=0 ? divide(options, bb, originalRightChildIndex, level+1) : 0;
bb._min[axis] = restore;
if (!insitueDivision)
{
// take a second reference to node we are working on as the std::vector<> resize could
// have invalidate the previous node ref.
KdTree::KdNode& newNodeRef = _kdTree.getNode(nodeIndex);
newNodeRef.first = leftChildIndex;
newNodeRef.second = rightChildIndex;
insitueDivision = true;
newNodeRef.bb.init();
if (leftChildIndex!=0) newNodeRef.bb.expandBy(_kdTree.getNode(leftChildIndex).bb);
if (rightChildIndex!=0) newNodeRef.bb.expandBy(_kdTree.getNode(rightChildIndex).bb);
if (!newNodeRef.bb.valid())
{
OSG_NOTICE<<"leftChildIndex="<<leftChildIndex<<" && originalLeftChildIndex="<<originalLeftChildIndex<<std::endl;
OSG_NOTICE<<"rightChildIndex="<<rightChildIndex<<" && originalRightChildIndex="<<originalRightChildIndex<<std::endl;
OSG_NOTICE<<"Invalid BB leftChildIndex="<<leftChildIndex<<", "<<rightChildIndex<<std::endl;
OSG_NOTICE<<" bb._min ("<<newNodeRef.bb._min<<")"<<std::endl;
OSG_NOTICE<<" bb._max ("<<newNodeRef.bb._max<<")"<<std::endl;
if (leftChildIndex!=0)
{
OSG_NOTICE<<" getNode(leftChildIndex).bb min = "<<_kdTree.getNode(leftChildIndex).bb._min<<std::endl;
OSG_NOTICE<<" max = "<<_kdTree.getNode(leftChildIndex).bb._max<<std::endl;
}
if (rightChildIndex!=0)
{
OSG_NOTICE<<" getNode(rightChildIndex).bb min = "<<_kdTree.getNode(rightChildIndex).bb._min<<std::endl;
OSG_NOTICE<<" max = "<<_kdTree.getNode(rightChildIndex).bb._max<<std::endl;
}
}
}
}
else
{
OSG_NOTICE<<"NOT expecting to get here"<<std::endl;
}
return nodeIndex;
}
////////////////////////////////////////////////////////////////////////////////
//
// KdTree::BuildOptions
KdTree::BuildOptions::BuildOptions():
_numVerticesProcessed(0),
_targetNumTrianglesPerLeaf(4),
_maxNumLevels(32)
{
}
////////////////////////////////////////////////////////////////////////////////
//
// KdTree
KdTree::KdTree() : _degenerateCount(0)
{
}
KdTree::KdTree(const KdTree& rhs, const osg::CopyOp& copyop):
Shape(rhs, copyop),
_degenerateCount(rhs._degenerateCount),
_vertices(rhs._vertices),
_kdNodes(rhs._kdNodes)
{
}
bool KdTree::build(BuildOptions& options, osg::Geometry* geometry)
{
BuildKdTree build(*this);
return build.build(options, geometry);
}
////////////////////////////////////////////////////////////////////////////////
//
// KdTreeBuilder
KdTreeBuilder::KdTreeBuilder():
osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN)
{
_kdTreePrototype = new osg::KdTree;
}
KdTreeBuilder::KdTreeBuilder(const KdTreeBuilder& rhs):
osg::Object(rhs),
osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN),
_buildOptions(rhs._buildOptions),
_kdTreePrototype(rhs._kdTreePrototype)
{
}
void KdTreeBuilder::apply(osg::Geometry& geometry)
{
osg::KdTree* previous = dynamic_cast<osg::KdTree*>(geometry.getShape());
if (previous) return;
osg::ref_ptr<osg::KdTree> kdTree = osg::clone(_kdTreePrototype.get());
if (kdTree->build(_buildOptions, &geometry))
{
geometry.setShape(kdTree.get());
}
}