FGFS-4.1/OpenSceneGraph
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Added support for detecting edge collapses which will overturn the local

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triangles.
This commit is contained in:
Robert Osfield
2004-04-19 20:06:26 +00:00
parent a1caa14a61
commit f72e9befc1
1 changed files with 161 additions and 20 deletions
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181
src/osgUtil/Simplifier.cpp
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@@ -92,6 +92,8 @@ public:
const osg::Vec3& vertex = point->_vertex;
float error = 0.0f;
if (triangles.empty()) return 0.0f;
for(LocalTriangleSet::iterator itr=triangles.begin();
itr!=triangles.end();
++itr)
@@ -99,6 +101,9 @@ public:
error += fabs( (*itr)->distance(vertex) );
}
// use average of error
error /= (float)triangles.size();
return error;
}
@@ -120,6 +125,7 @@ public:
edge->_proposedPoint = computeOptimalPoint(edge);
edge->updateMaxNormalDeviationOnEdgeCollapse();
edge->setErrorMetric( computeErrorMetric( edge, edge->_proposedPoint.get()));
_edgeSet.insert(keep_local_reference_to_edge);
@@ -140,6 +146,7 @@ public:
Edge* edge = itr->get();
edge->_proposedPoint = computeOptimalPoint(edge);
edge->updateMaxNormalDeviationOnEdgeCollapse();
edge->setErrorMetric( computeErrorMetric( edge, edge->_proposedPoint.get()));
_edgeSet.insert(edge);
@@ -174,6 +181,7 @@ public:
typedef std::vector< osg::ref_ptr<Point> > PointList;
typedef std::list< osg::ref_ptr<Triangle> > TriangleList;
typedef std::set< osg::ref_ptr<Triangle> > TriangleSet;
typedef std::map< osg::ref_ptr<Triangle>, unsigned int, dereference_less > TriangleMap;
struct Point : public osg::Referenced
{
@@ -213,7 +221,7 @@ public:
struct Edge : public osg::Referenced
{
Edge(): _errorMetric(0.0f) {}
Edge(): _errorMetric(0.0f), _maximumDeviation(1.0f) {}
osg::ref_ptr<Point> _p1;
osg::ref_ptr<Point> _p2;
@@ -221,6 +229,7 @@ public:
TriangleSet _triangles;
float _errorMetric;
float _maximumDeviation;
osg::ref_ptr<Point> _proposedPoint;
@@ -234,7 +243,7 @@ public:
else if (rhs.getErrorMetric()<getErrorMetric()) return false;
if (_p1 < rhs._p1) return true;
if (rhs._p1 < _p1) return false;
else if (rhs._p1 < _p1) return false;
return (_p2 < rhs._p2);
}
@@ -258,7 +267,7 @@ public:
void addTriangle(Triangle* triangle)
{
_triangles.insert(triangle);
if (_triangles.size()>2) osg::notify(osg::NOTICE)<<"Warning too many traingles ("<<_triangles.size()<<") sharing edge "<<std::endl;
// if (_triangles.size()>2) osg::notify(osg::NOTICE)<<"Warning too many traingles ("<<_triangles.size()<<") sharing edge "<<std::endl;
}
bool isBoundaryEdge() const
@@ -271,6 +280,33 @@ public:
return isBoundaryEdge() || _p1->isBoundaryPoint() || _p2->isBoundaryPoint();
}
void updateMaxNormalDeviationOnEdgeCollapse()
{
//std::cout<<"updateMaxNormalDeviationOnEdgeCollapse()"<<std::endl;
_maximumDeviation = 0.0f;
for(TriangleSet::iterator itr1=_p1->_triangles.begin();
itr1!=_p1->_triangles.end();
++itr1)
{
if (_triangles.count(*itr1)==0)
{
_maximumDeviation = osg::maximum(_maximumDeviation, (*itr1)->computeNormalDeviationOnEdgeCollapse(this,_proposedPoint.get()));
}
}
for(TriangleSet::iterator itr2=_p2->_triangles.begin();
itr2!=_p2->_triangles.end();
++itr2)
{
if (_triangles.count(*itr2)==0)
{
_maximumDeviation = osg::maximum(_maximumDeviation, (*itr2)->computeNormalDeviationOnEdgeCollapse(this,_proposedPoint.get()));
}
}
}
float getMaxNormalDeviationOnEdgeCollapse() const { return _maximumDeviation; }
};
struct Triangle : public osg::Referenced
@@ -282,27 +318,67 @@ public:
if (_p1 < rhs._p1) return true;
if (rhs._p1 < _p1) return false;
if (_p2 < rhs._p2) return true;
if (rhs._p2 < _p2) return false;
return (_p3 < rhs._p3);
const Point* lhs_lower = _p2<_p3 ? _p2.get() : _p3.get();
const Point* rhs_lower = rhs._p2<rhs._p3 ? rhs._p2.get() : rhs._p3.get();
if (lhs_lower < rhs_lower) return true;
if (rhs_lower < lhs_lower) return false;
const Point* lhs_upper = _p2<_p3 ? _p3.get() : _p2.get();
const Point* rhs_upper = rhs._p2<rhs._p3 ? rhs._p3.get() : rhs._p2.get();
return (lhs_upper < rhs_upper);
}
osg::ref_ptr<Point> _p1;
osg::ref_ptr<Point> _p2;
osg::ref_ptr<Point> _p3;
osg::ref_ptr<Edge> _e1;
osg::ref_ptr<Edge> _e2;
osg::ref_ptr<Edge> _e3;
osg::Plane _plane;
void setOrderedPoints(Point* p1, Point* p2, Point* p3)
{
Point* points[3];
points[0] = p1;
points[1] = p2;
points[2] = p3;
// find the lowest value point in the list.
unsigned int lowest = 0;
if (points[1]<points[lowest]) lowest = 1;
if (points[2]<points[lowest]) lowest = 2;
_p1 = points[lowest];
_p2 = points[(lowest+1)%3];
_p3 = points[(lowest+2)%3];
}
void update()
{
_plane.set(_p1->_vertex,_p2->_vertex,_p3->_vertex);
}
osg::Plane computeNewPlaneOnEdgeCollapse(Edge* edge,Point* pNew) const
{
const Point* p1 = (_p1==edge->_p1 || _p1==edge->_p2) ? pNew : _p1.get();
const Point* p2 = (_p2==edge->_p1 || _p2==edge->_p2) ? pNew : _p2.get();
const Point* p3 = (_p3==edge->_p1 || _p3==edge->_p2) ? pNew : _p3.get();
return osg::Plane(p1->_vertex,p2->_vertex,p3->_vertex);
}
// note return 1 - dotproduct, so that deviation is in the range of 0.0 to 2.0, where 0 is coincendent, 1.0 is 90 degrees, and 2.0 is 180 degrees.
float computeNormalDeviationOnEdgeCollapse(Edge* edge,Point* pNew) const
{
const Point* p1 = (_p1==edge->_p1 || _p1==edge->_p2) ? pNew : _p1.get();
const Point* p2 = (_p2==edge->_p1 || _p2==edge->_p2) ? pNew : _p2.get();
const Point* p3 = (_p3==edge->_p1 || _p3==edge->_p2) ? pNew : _p3.get();
osg::Vec3 new_normal = (p2->_vertex - p1->_vertex) ^ (p3->_vertex - p2->_vertex);
new_normal.normalize();
float result = 1.0f - (new_normal.x() * _plane[0] + new_normal.y() * _plane[1] + new_normal.z() * _plane[2]);
return result;
}
float distance(const osg::Vec3& vertex) const
{
return _plane.distance(vertex);
@@ -312,6 +388,18 @@ public:
{
return (_e1->isBoundaryEdge() || _e2->isBoundaryEdge() || _e3->isBoundaryEdge());
}
osg::ref_ptr<Point> _p1;
osg::ref_ptr<Point> _p2;
osg::ref_ptr<Point> _p3;
osg::ref_ptr<Edge> _e1;
osg::ref_ptr<Edge> _e2;
osg::ref_ptr<Edge> _e3;
osg::Plane _plane;
};
@@ -512,13 +600,13 @@ public:
EdgeSet::iterator itr = _edgeSet.find(edge);
if (itr==_edgeSet.end())
{
//std::cout<<" addEdge("<<edge.get()<<")"<<std::endl;
// std::cout<<" addEdge("<<edge.get()<<") edge->_p1="<<edge->_p1.get()<<" _p2="<<edge->_p2.get()<<std::endl;
_edgeSet.insert(edge);
}
else
{
// std::cout<<" reuseEdge("<<edge.get()<<") edge->_p1="<<edge->_p1.get()<<" _p2="<<edge->_p2.get()<<std::endl;
edge = *itr;
//std::cout<<" reuseEdge("<<edge.get()<<")"<<std::endl;
}
edge->addTriangle(triangle);
@@ -591,6 +679,18 @@ public:
bool collapseEdge(Edge* edge, Point* pNew)
{
if (edge->_triangles.size()<2) return false;
if (edge->_triangles.size()>2) return false;
if (edge->getMaxNormalDeviationOnEdgeCollapse()>1.0)
{
std::cout<<"collapseEdge("<<edge<<") refused due to edge->getMaxNormalDeviationOnEdgeCollapse() = "<<edge->getMaxNormalDeviationOnEdgeCollapse()<<std::endl;
return false;
}
else
{
//std::cout<<"collapseEdge("<<edge<<") edge->getMaxNormalDeviationOnEdgeCollapse() = "<<edge->getMaxNormalDeviationOnEdgeCollapse()<<std::endl;
}
typedef std::set< osg::ref_ptr<Edge> > LocalEdgeList;
@@ -599,10 +699,12 @@ public:
osg::ref_ptr<Point> edge_p1 = edge->_p1;
osg::ref_ptr<Point> edge_p2 = edge->_p2;
TriangleMap triangleMap;
TriangleList triangles_p1;
TriangleList triangles_p2;
LocalEdgeList oldEdges;
if (edge_p1 != pNew)
{
for(TriangleSet::iterator itr=edge_p1->_triangles.begin();
@@ -665,23 +767,29 @@ public:
removeTriangle(const_cast<Triangle*>(titr_p2->get()));
}
//std::cout<<" pNew="<<pNew<<"\tedge_p1"<<edge_p1.get()<<"\tedge_p2"<<edge_p2.get()<<std::endl;
for(TriangleSet::iterator teitr=edge->_triangles.begin();
teitr!=edge->_triangles.end();
++teitr)
{
removeTriangle(const_cast<Triangle*>(teitr->get()));
Triangle* triangle = const_cast<Triangle*>(teitr->get());
//std::cout<<" edge removed T("<<triangle->_p1.get()<<"\t"<<triangle->_p2.get()<<"\t"<<triangle->_p3.get()<<")"<<std::endl;
removeTriangle(triangle);
}
LocalEdgeList newEdges;
for(TriangleList::iterator titr_p1 = triangles_p1.begin();
titr_p1 != triangles_p1.end();
++titr_p1)
{
Triangle* triangle = const_cast<Triangle*>(titr_p1->get());
Point* p1 = (triangle->_p1==edge_p1 || triangle->_p1==edge_p2)? pNew : triangle->_p1.get();
Point* p2 = (triangle->_p2==edge_p1 || triangle->_p2==edge_p2)? pNew : triangle->_p2.get();
Point* p3 = (triangle->_p3==edge_p1 || triangle->_p3==edge_p2)? pNew : triangle->_p3.get();
Triangle* newTri = addTriangle(p1,p2,p3);
newEdges.insert(newTri->_e1);
@@ -689,23 +797,27 @@ public:
newEdges.insert(newTri->_e3);
}
for(TriangleList::iterator titr_p2 = triangles_p2.begin();
titr_p2 != triangles_p2.end();
++titr_p2)
{
Triangle* triangle = const_cast<Triangle*>(titr_p2->get());
Point* p1 = (triangle->_p1==edge_p1 || triangle->_p1==edge_p2)? pNew : triangle->_p1.get();
Point* p2 = (triangle->_p2==edge_p1 || triangle->_p2==edge_p2)? pNew : triangle->_p2.get();
Point* p3 = (triangle->_p3==edge_p1 || triangle->_p3==edge_p2)? pNew : triangle->_p3.get();
Triangle* newTri = addTriangle(p1,p2,p3);
newEdges.insert(newTri->_e1);
newEdges.insert(newTri->_e2);
newEdges.insert(newTri->_e3);
}
#if 1
// std::cout<<"Edges to recalibarate "<<newEdges.size()<<std::endl;
for(LocalEdgeList::iterator itr=newEdges.begin();
@@ -715,7 +827,7 @@ public:
//std::cout<<"updateErrorMetricForEdge("<<itr->get()<<")"<<std::endl;
updateErrorMetricForEdge(const_cast<Edge*>(itr->get()));
}
#endif
return true;
}
@@ -1158,6 +1270,28 @@ class CopyPointsToArrayVisitor : public osg::ArrayVisitor
unsigned int _index;
};
class NormalizeArrayVisitor : public osg::ArrayVisitor
{
public:
NormalizeArrayVisitor() {}
template<typename Itr>
void normalize(Itr begin, Itr end)
{
for(Itr itr = begin;
itr != end;
++itr)
{
itr->normalize();
}
}
virtual void apply(osg::Vec2Array& array) { normalize(array.begin(),array.end()); }
virtual void apply(osg::Vec3Array& array) { normalize(array.begin(),array.end()); }
virtual void apply(osg::Vec4Array& array) { normalize(array.begin(),array.end()); }
};
class CopyPointsToVertexArrayVisitor : public osg::ArrayVisitor
{
public:
@@ -1202,6 +1336,7 @@ class CopyPointsToVertexArrayVisitor : public osg::ArrayVisitor
EdgeCollapse::PointList& _pointList;
};
void EdgeCollapse::copyBackToGeometry()
{
#if 1
@@ -1258,7 +1393,13 @@ void EdgeCollapse::copyBackToGeometry()
}
if (_geometry->getNormalArray() && _geometry->getNormalBinding()==osg::Geometry::BIND_PER_VERTEX)
{
_geometry->getNormalArray()->accept(copyArrayToPoints);
// now normalize the normals.
NormalizeArrayVisitor nav;
_geometry->getNormalArray()->accept(nav);
}
if (_geometry->getColorArray() && _geometry->getColorBinding()==osg::Geometry::BIND_PER_VERTEX)
_geometry->getColorArray()->accept(copyArrayToPoints);