RE: [osg-users] Bounding Rect in Screen Space
Since I didn't get any responses to my last email, perhaps if I provide
code I'll have more luck. Can someone tell me why this code doesn't work
for calculating the bounding rectangle of an object in screen space.
What I would expect to see is that the rectangle would get drawn right
over the top of the object, but its always wrong. Please note that the
object in question is part of a model that I am rendering to a texture
and then applying the texture to a polygon that covers the entire
screen. So I need a way to tell if the mouse is over the top of a
particular piece of the model. So I am trying to calculate the bounding
rect of that part of the model, but I've tried about 5 different ways of
calculating it (the code below being my most recent attempt) and I get
pretty much the same result with all 5 different ways of doing it (see
attached image):
//This is my custom cull callback function
virtual void operator()(osg::Node *pNode, osg::NodeVisitor *pNV)
{
if(m_spGeode-getNumDrawables() 0)
m_spGeode-removeDrawables(0, m_spGeode-getNumDrawables());
osgUtil::CullVisitor* pCullVisitor =
dynamic_castosgUtil::CullVisitor*(pNV);
osg::BoundingBox bb;
bb.expandBy(pNode-getBound());
m_rect.minPt.set(SHRT_MAX, SHRT_MAX);
m_rect.maxPt.set(SHRT_MIN, SHRT_MIN);
CalculateScreenSpaceBoundingRect(bb, pCullVisitor, m_rect);
m_spGeode-addDrawable(CreateScreenPolygon(osg::BoundingBox(m_rect.minPt
.x(),
m_rect.minPt.y(),
0.0f,
m_rect.maxPt.x(),
m_rect.maxPt.y(),
0.0f), 0.5f));
pCullVisitor-traverse(*pNode);
}
void CalculateScreenSpaceBoundingRect(const osg::BoundingBox bb,
osgUtil::CullVisitor* pCullVisitor, M2CompassModel::BoundingRect brect)
{
const osg::RefMatrix MVPW = pCullVisitor-getMVPW();
//point #1
osg::Vec4 vtx(bb.xMin(), bb.yMin(), bb.zMin(), 1.0f);
osg::Vec4 screenVtx = MVPW.preMult(vtx);
brect.expand(screenVtx);
//... This is repeated for each point in the bounding box
}
osg::Geometry* CreateScreenPolygon(const osg::BoundingBox bb, float
red)
{
osg::Geometry* polyGeom = new osg::Geometry();
osg::Vec3Array* vertices = new osg::Vec3Array;
float depth = bb.zMin()-0.1;
vertices-push_back(osg::Vec3(bb.xMin(),bb.yMax(),depth));
vertices-push_back(osg::Vec3(bb.xMin(),bb.yMin(),depth));
vertices-push_back(osg::Vec3(bb.xMax(),bb.yMin(),depth));
vertices-push_back(osg::Vec3(bb.xMax(),bb.yMax(),depth));
polyGeom-setVertexArray(vertices);
osg::Vec3Array* normals = new osg::Vec3Array;
normals-push_back(osg::Vec3(0.0f,0.0f,1.0f));
polyGeom-setNormalArray(normals);
polyGeom-setNormalBinding(osg::Geometry::BIND_OVERALL);
osg::Vec4Array* colors = new osg::Vec4Array;
colors-push_back(osg::Vec4(red,1.0f,1.0f,1.0f));
polyGeom-setColorArray(colors);
polyGeom-setColorBinding(osg::Geometry::BIND_OVERALL);
polyGeom-addPrimitiveSet(new
osg::DrawArrays(osg::PrimitiveSet::QUADS,0,vertices-size()));
return polyGeom;
}
Any suggestions? Thanks.
Alex
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Pecoraro,
Alexander N
Sent: Tuesday, July 03, 2007 9:48 AM
To: osg users
Subject: [osg-users] Bounding Rect in Screen Space
Is there an easy way to calculate the bounding rectangle of an object in
screen space? I'm hoping for some easy function that I could pass my
osg::Node to and have it return the bounding rectangle of the pixels
that it covers.
Thanks.
Alex
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[osg-users] Bounding Rect in Screen Space
Is there an easy way to calculate the bounding rectangle of an object in screen space? I'm hoping for some easy function that I could pass my osg::Node to and have it return the bounding rectangle of the pixels that it covers. Thanks. Alex ___ osg-users mailing list osg-users@openscenegraph.net http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
RE: [osg-users] OpenFlight plugin threadsafe?
I am using 1.2. I will try upgrading to 2.0. Alex -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Robert Osfield Sent: Saturday, June 30, 2007 1:18 AM To: osg users Subject: Re: [osg-users] OpenFlight plugin threadsafe? Hi Alex, The OpenFlight plugin does not support multi-threaded usage, but does have a reentrant mutex to marshal access through it - effectively serializing access to it. There was a point when the OpenFlight plugin didn't yet have this serializing feature. Which version of the OSG are you using? When using the DatabasePager it runs its own background thread for doing the file reading and data prep, there is only currently one thread that it runs, so typically reading from plugins is still still single-threaded. Oh yea - I am using the plugin in src/osgPlugins/OpenFlight, not the one in src/osgPlugins/flt. Out of curiosity, why is there two different plugins for the same file type? OSG-2.0 only has the new OpenFlight plugin, the old flt plugin has been removed. In 1.2 we kept the flt plugin around for cases where the new plugin wasn't quite mature enough. Robert. On 6/30/07, Pecoraro, Alexander N [EMAIL PROTECTED] wrote: Hi, I was wondering if anyone was using the OpenFlight ReaderWriter plugin in combination with the osgDB::DatabasePager? I modified the plugin so that it creates PagedLOD nodes for external reference records, instead of ProxyNodes, so that I could have paging functionality in my OpenFlight terrain. I made sure to set thread safe reference counting to true, but I still seem to get segfaults when I fly around the terrain. It appears to happen in the std::vector class when the OpenFlight plugin tries to add some new object, such as a vertex, to a vector. I'm just trying to confirm whether it could be something that I caused or if the OpenFlight plugin doesn't work well with the database pager. So if anyone has used openflight files with the database pager please let me know. Thanks. Alex ___ osg-users mailing list osg-users@openscenegraph.net http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/ ___ osg-users mailing list osg-users@openscenegraph.net http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/ ___ osg-users mailing list osg-users@openscenegraph.net http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
[osg-users] OpenFlight plugin threadsafe?
Hi, I was wondering if anyone was using the OpenFlight ReaderWriter plugin in combination with the osgDB::DatabasePager? I modified the plugin so that it creates PagedLOD nodes for external reference records, instead of ProxyNodes, so that I could have paging functionality in my OpenFlight terrain. I made sure to set thread safe reference counting to true, but I still seem to get segfaults when I fly around the terrain. It appears to happen in the std::vector class when the OpenFlight plugin tries to add some new object, such as a vertex, to a vector. I'm just trying to confirm whether it could be something that I caused or if the OpenFlight plugin doesn't work well with the database pager. So if anyone has used openflight files with the database pager please let me know. Oh yea - I am using the plugin in src/osgPlugins/OpenFlight, not the one in src/osgPlugins/flt. Out of curiosity, why is there two different plugins for the same file type? Thanks. Alex ___ osg-users mailing list osg-users@openscenegraph.net http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
