Hi Peter,
thank you for the fast reply.
I need some clarifications about question 1.
In my application I will use the "picked" point to calculate, and then show,
the arclength of a path, i.e. the length of the path from start to the picked
point. So I would not need to show coordinates to the user. So I guess WINDOW
or PROJECTION would be the same for my case.
But I would like to understand why I get different coordinates from
"intersection.localIntersectionPoint" with osgUtil::Intersector::WINDOW wrt
osgUtil::Intersector::PROJECTION
Here is a code snippet as an example:
Code:
osgUtil::PolytopeIntersector* picker;
{
osg::Viewport* viewport = viewer->getCamera()->getViewport();
double mx = viewport->x() + (int)((double
)viewport->width()*(ea.getXnormalized()*0.5+0.5));
double my = viewport->y() + (int)((double
)viewport->height()*(ea.getYnormalized()*0.5+0.5));
double w = 5.0f;
double h = 5.0f;
picker = new osgUtil::PolytopeIntersector( osgUtil::Intersector::WINDOW,
mx-w, my-h, mx+w, my+h );
osgUtil::IntersectionVisitor iv(picker);
viewer->getCamera()->accept(iv);
if (picker->containsIntersections())
{
osgUtil::PolytopeIntersector::Intersection intersection =
picker->getFirstIntersection();
std::cout << "osgUtil::Intersector::WINDOW " <<
intersection.localIntersectionPoint.x() << " " <<
intersection.localIntersectionPoint.y() << " " <<
intersection.localIntersectionPoint.z() << std::endl;
}
}
{
double mx = ea.getXnormalized();
double my = ea.getYnormalized();
double w = 0.05;
double h = 0.05;
picker = new osgUtil::PolytopeIntersector(
osgUtil::Intersector::PROJECTION, mx-w, my-h, mx+w, my+h );
osgUtil::IntersectionVisitor iv(picker);
viewer->getCamera()->accept(iv);
if (picker->containsIntersections())
{
osgUtil::PolytopeIntersector::Intersection intersection =
picker->getFirstIntersection();
std::cout << "osgUtil::Intersector::PROJECTION " <<
intersection.localIntersectionPoint.x() << " " <<
intersection.localIntersectionPoint.y() << " " <<
intersection.localIntersectionPoint.z() << std::endl;
}
}
And I get an output like this:
osgUtil::Intersector::WINDOW 18.8821 0.0163024 0
osgUtil::Intersector::PROJECTION 31.7343 0.0274029 0
osgUtil::Intersector::WINDOW 18.8821 0.0163024 0
osgUtil::Intersector::PROJECTION 31.7343 0.0274029 0
osgUtil::Intersector::WINDOW 22.529 0.019452 0
osgUtil::Intersector::PROJECTION 34.8797 0.0301198 0
The WINDOW case shows different coordinates (look at X coordinate please) wrt
PROJECTION case, but they does not seem to be one in pixel and the other
normalized. Am I missing something?
Moreover in the WINDOW case I need to be closer to the geomwetry to get a valid
intersection. Can you explain me please why?
Best regards,
Gianni
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=61495#61495
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