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From Ravi Mathur, "OK I have been away for a looong time, but still occasionally watching from a distance, and saw the bug people have reported about the DepthPartitionNode not handling scaled models properly.

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I believe this is now fixed ... I have attached the new DistanceAccumulator.cpp, along with a modified example file that uses a PositionAttitudeTransform to draw the Earth's orbit around the Sun."
This commit is contained in:
Robert Osfield
2009-04-09 14:25:14 +00:00
parent 38b02a26a9
commit fddaaf0d00
2 changed files with 136 additions and 40 deletions
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102
examples/osgdepthpartition/DistanceAccumulator.cpp
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@@ -34,9 +34,13 @@ bool precedes(const DistanceAccumulator::DistancePair &a,
else return false;
}
/** Computes distance betwen a point and the viewpoint of a matrix */
/** Computes distance (in z direction) betwen a point and the viewer's eye,
given by a view matrix */
double distance(const osg::Vec3 &coord, const osg::Matrix& matrix)
{
// Here we are taking only the z coordinate of the point transformed
// by the matrix, ie coord*matrix. The negative sign is because we
// want to consider into the screen as INCREASING distance.
return -( coord[0]*matrix(0,2) + coord[1]*matrix(1,2) +
coord[2]*matrix(2,2) + matrix(3,2) );
}
@@ -56,19 +60,19 @@ void CURRENT_CLASS::pushLocalFrustum()
{
osg::Matrix& currMatrix = _viewMatrices.back();
// Compute the frustum in local space
osg::Polytope localFrustum;
localFrustum.setToUnitFrustum(false, false);
localFrustum.transformProvidingInverse(currMatrix*_projectionMatrices.back());
_localFrusta.push_back(localFrustum);
// Compute the frustum in local space
osg::Polytope localFrustum;
localFrustum.setToUnitFrustum(false, false);
localFrustum.transformProvidingInverse(currMatrix*_projectionMatrices.back());
_localFrusta.push_back(localFrustum);
// Compute new bounding box corners
bbCornerPair corner;
corner.second = (currMatrix(0,2)<=0?1:0) |
(currMatrix(1,2)<=0?2:0) |
(currMatrix(2,2)<=0?4:0);
corner.first = (~corner.second)&7;
_bbCorners.push_back(corner);
// Compute new bounding box corners
bbCornerPair corner;
corner.second = (currMatrix(0,2)<=0?1:0) |
(currMatrix(1,2)<=0?2:0) |
(currMatrix(2,2)<=0?4:0);
corner.first = (~corner.second)&7;
_bbCorners.push_back(corner);
}
void CURRENT_CLASS::pushDistancePair(double zNear, double zFar)
@@ -99,19 +103,57 @@ bool CURRENT_CLASS::shouldContinueTraversal(osg::Node &node)
// Allow traversal to continue if we haven't reached maximum depth.
bool keepTraversing = (_currentDepth < _maxDepth);
const osg::BoundingSphere &bs = node.getBound();
osg::BoundingSphere bs = node.getBound();
double zNear = 0.0, zFar = 0.0;
// Make sure bounding sphere is valid and within viewing volume
// Make sure bounding sphere is valid
if(bs.valid())
{
// Make sure bounding sphere is within the viewing volume
if(!_localFrusta.back().contains(bs)) keepTraversing = false;
else
else // Compute near and far planes for this node
{
// Compute near and far planes for this node
zNear = distance(bs._center, _viewMatrices.back());
zFar = zNear + bs._radius;
zNear -= bs._radius;
// Since the view matrix could involve complex transformations,
// we need to determine a new BoundingSphere that would encompass
// the transformed BoundingSphere.
const osg::Matrix &l2w = _viewMatrices.back();
// Get the transformed x-axis of the BoundingSphere
osg::Vec3d newX = bs._center;
newX.x() += bs._radius; // Get X-edge of bounding sphere
newX = newX * l2w;
// Get the transformed y-axis of the BoundingSphere
osg::Vec3d newY = bs._center;
newY.y() += bs._radius; // Get Y-edge of bounding sphere
newY = newY * l2w;
// Get the transformed z-axis of the BoundingSphere
osg::Vec3d newZ = bs._center;
newZ.z() += bs._radius; // Get Z-edge of bounding sphere
newZ = newZ * l2w;
// Get the transformed center of the BoundingSphere
bs._center = bs._center * l2w;
// Compute lengths of transformed x, y, and z axes
double newXLen = (newX - bs._center).length();
double newYLen = (newY - bs._center).length();
double newZLen = (newZ - bs._center).length();
// The encompassing radius is the max of the transformed lengths
bs._radius = newXLen;
if(newYLen > bs._radius) bs._radius = newYLen;
if(newZLen > bs._radius) bs._radius = newZLen;
// Now we can compute the near & far planes, noting that for
// complex view transformations (ie. involving scales) the new
// BoundingSphere may be bigger than the original one.
// Note that the negative sign on the bounding sphere center is
// because we want distance to increase INTO the screen.
zNear = -bs._center.z() - bs._radius;
zFar = -bs._center.z() + bs._radius;
// If near/far ratio is big enough, then we don't need to keep
// traversing children of this node.
@@ -130,9 +172,9 @@ void CURRENT_CLASS::apply(osg::Node &node)
if(shouldContinueTraversal(node))
{
// Traverse this node
_currentDepth++;
++_currentDepth;
traverse(node);
_currentDepth--;
--_currentDepth;
}
}
@@ -145,9 +187,9 @@ void CURRENT_CLASS::apply(osg::Projection &proj)
pushLocalFrustum();
// Traverse the group
_currentDepth++;
++_currentDepth;
traverse(proj);
_currentDepth--;
--_currentDepth;
// Reload original matrix and frustum
_localFrusta.pop_back();
@@ -171,9 +213,9 @@ void CURRENT_CLASS::apply(osg::Transform &transform)
pushLocalFrustum();
}
_currentDepth++;
++_currentDepth;
traverse(transform);
_currentDepth--;
--_currentDepth;
if(pushMatrix)
{
@@ -195,7 +237,7 @@ void CURRENT_CLASS::apply(osg::Geode &geode)
double zNear, zFar;
// Handle each drawable in this geode
for(unsigned int i = 0; i < geode.getNumDrawables(); i++)
for(unsigned int i = 0; i < geode.getNumDrawables(); ++i)
{
drawable = geode.getDrawable(i);
@@ -268,7 +310,7 @@ void CURRENT_CLASS::computeCameraPairs()
// pairs (called combined pairs) will not overlap.
PairList combinedPairs;
DistancePair currPair = _distancePairs.front();
for(i = _distancePairs.begin(); i != _distancePairs.end(); i++)
for(i = _distancePairs.begin(); i != _distancePairs.end(); ++i)
{
// Current distance pair does not overlap current combined pair, so
// save the current combined pair and start a new one.
@@ -290,7 +332,7 @@ void CURRENT_CLASS::computeCameraPairs()
double currNearLimit, numSegs, new_ratio;
double ratio_invlog = 1.0/log(_nearFarRatio);
unsigned int temp;
for(i = combinedPairs.begin(); i != combinedPairs.end(); i++)
for(i = combinedPairs.begin(); i != combinedPairs.end(); ++i)
{
currPair = *i; // Save current view segment
@@ -311,7 +353,7 @@ void CURRENT_CLASS::computeCameraPairs()
}
// See if the closest view segment can absorb other combined pairs
for(j = i+1; j != combinedPairs.end(); j++)
for(j = i+1; j != combinedPairs.end(); ++j)
{
// No other distance pairs can be included
if(j->first < currNearLimit) break;