Hi, we have a bunch of classes that inherit osg::Node, and they create their own, internal geometry which is passed into the render bucket at the cull-traversal. Last week, we realised that these classes are not accounted for when doing an ComputeBoundVisitor- traversal, as there is no specialization in ComputeBoundVisitor for them.
One solution is naturally to create a new class that would inherit the osg::ComputeBoundVisitor, and use that. I don't like that idea as the ComputeBoundVisitor does actually have what I need - it is only hidden in a protected function. I am therefor suggesting a slight generalization of the ComputeBoundVisitor with the attached patch, which is tested. The patch has two parts: 1. we add applyBBox() so that one can use that in a customized traverse-function and add a bbox to the visitor. I considered calling this function expandByBBox(), but I though applyBBox was better. 2. The MatrixStack is made available to the outside world. That enables a traverse-function to do whatever it wishes. I do actually only need one of the two, as I can implement what I wish either way, but adding getMatrixStack() will make more generic expansions possible. I wonder if you please could consider this change for the trunk. Best regards, Kristofer Tingdahl
/* -*-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/ComputeBoundsVisitor>
#include <osg/Transform>
#include <osg/Drawable>
#include <osg/Geode>
using namespace osg;
ComputeBoundsVisitor::ComputeBoundsVisitor(TraversalMode traversalMode):
osg::NodeVisitor(traversalMode)
{
}
void ComputeBoundsVisitor::reset()
{
_matrixStack.clear();
_bb.init();
}
void ComputeBoundsVisitor::getPolytope(osg::Polytope& polytope, float margin) const
{
float delta = _bb.radius()*margin;
polytope.add( osg::Plane(0.0, 0.0, 1.0, -(_bb.zMin()-delta)) );
polytope.add( osg::Plane(0.0, 0.0, -1.0, (_bb.zMax()+delta)) );
polytope.add( osg::Plane(1.0, 0.0, 0.0, -(_bb.xMin()-delta)) );
polytope.add( osg::Plane(-1.0, 0.0, 0.0, (_bb.xMax()+delta)) );
polytope.add( osg::Plane(0.0, 1.0, 0.0, -(_bb.yMin()-delta)) );
polytope.add( osg::Plane(0.0, -1.0, 0.0, (_bb.yMax()+delta)) );
}
void ComputeBoundsVisitor::getBase(osg::Polytope& polytope, float margin) const
{
float delta = _bb.radius()*margin;
polytope.add( osg::Plane(0.0, 0.0, 1.0, -(_bb.zMin()-delta)) );
}
void ComputeBoundsVisitor::apply(osg::Node& node)
{
traverse(node);
}
void ComputeBoundsVisitor::apply(osg::Transform& transform)
{
osg::Matrix matrix;
if (!_matrixStack.empty()) matrix = _matrixStack.back();
transform.computeLocalToWorldMatrix(matrix,this);
pushMatrix(matrix);
traverse(transform);
popMatrix();
}
void ComputeBoundsVisitor::apply(osg::Geode& geode)
{
for(unsigned int i=0; i<geode.getNumDrawables(); ++i)
{
applyDrawable(geode.getDrawable(i));
}
}
void ComputeBoundsVisitor::applyDrawable(osg::Drawable* drawable)
{
applyBBox(drawable->getBound());
}
void ComputeBoundsVisitor::applyBBox(const osg::BoundingBox& bbox)
{
if (_matrixStack.empty()) _bb.expandBy(bbox);
else if (bbox.valid())
{
const osg::Matrix& matrix = _matrixStack.back();
_bb.expandBy(bbox.corner(0) * matrix);
_bb.expandBy(bbox.corner(1) * matrix);
_bb.expandBy(bbox.corner(2) * matrix);
_bb.expandBy(bbox.corner(3) * matrix);
_bb.expandBy(bbox.corner(4) * matrix);
_bb.expandBy(bbox.corner(5) * matrix);
_bb.expandBy(bbox.corner(6) * matrix);
_bb.expandBy(bbox.corner(7) * matrix);
}
}
ComputeBoundsVisitor
Description: Binary data
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