[osg-users] multi camera rendering and pick issues
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Emmanuel Roche
Sep 23, 2008, 6:42:12 AM9/23/08
to OSG Users
Hi everyone,
I have an interesting issue here:
I'm building a scene this way (the following is a lua script using osgIntrospection to manipulate OSG stuff) :
local root = osg.Group()
root:setName("Universe")
-- we want to add this root object as a scene in the current project (otherwise it will never be found)
-- this root object will be assigned as the scenedata for the master camera.
local proj = vProj.ProjectManager.instance():getCurrent()
proj:add_Scene(root)
local view = vDisplay.DisplayManager.getViewer():getView(0) -- here, getViewer() returns our osgViewer::CompositeViewer object
local manip = reflection.cast(view:getCameraManipulator(),"vGA::ArcBallManipulator")
-- now create the LTS project:
require('LTS')
local cam = view:getCamera() -- this is the "main" camera, the scene data for this camera is the previously declared "root" object
local subcam = osg.Camera() -- we create a sub camera than we will add to the main scene (so an inderect child for the main camera...)
subcam:setGraphicsContext(cam:getGraphicsContext())
subcam:setViewport(cam:getViewport())
subcam:setRenderOrder(osg.Camera.RenderOrder.POST_RENDER,3) -- We post render this subcamera with an arbitrary order.
subcam:setClearMask(GL.Mode.GL_DEPTH_BUFFER_BIT) -- We want to render Universe scale scenes that's why we introduced this multi pass system.
root:addChild(subcam)
local st = vOGL.SceneTools;
local pat = osg.PositionAttitudeTransform()
pat:addChild(LTS.createDoubleCraft("K1")) -- Here we create a satellit object
subcam:addChild(pat) -- And we add the object to the sub camera...
... this scene is rendered perfectly... but now I'm trying to "pick" items in the scene using the implementation found in osgViewer::View::computeIntersections(...) : If I put my "K1" object directly "in" the "main" camera everything is perfect, and I can pick intersections correctly. But when using this "subcam" as parent then I get incorrect results :-( (intersections found when clicking on nothing, or no intersections found when cliking on sub parts of the object...)
I gave a look at the osgUtil::IntersectionVisitor implementation... and I think everything is happening in this function:
void IntersectionVisitor::apply(osg::Camera& camera)
{
// osg::notify(osg::NOTICE)<<"apply(Camera&)"<<std::endl;
// note, commenting out right now because default Camera setup is with the culling active. Should this be changed?
// if (!enter(camera)) return;
// osg::notify(osg::NOTICE)<<"inside apply(Camera&)"<<std::endl;
if (camera.getViewport()) pushWindowMatrix( camera.getViewport() );
pushProjectionMatrix( new osg::RefMatrix(camera.getProjectionMatrix()) );
pushViewMatrix( new osg::RefMatrix(camera.getViewMatrix()) );
pushModelMatrix( new osg::RefMatrix() );
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
popModelMatrix();
popViewMatrix();
popProjectionMatrix();
if (camera.getViewport()) popWindowMatrix();
// leave();
}
I created my own "ExtendedIntersectorVisitor" (derived from this class) to override this function and I made multiple tests to handle the "main" camera and the "sub" cameras differently:
void ExtendedIntersectionVisitor::apply(osg::Camera & camera) {
if(!cameraInitialized) {
cameraInitialized = true;
// The first time we get a camera object we use it to setup the camera details normaly:
if (camera.getViewport()) pushWindowMatrix( camera.getViewport() );
pushProjectionMatrix( new osg::RefMatrix(camera.getProjectionMatrix()) );
pushViewMatrix( new osg::RefMatrix(camera.getViewMatrix()) );
pushModelMatrix( new osg::RefMatrix() );
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
popModelMatrix();
popViewMatrix();
popProjectionMatrix();
if (camera.getViewport()) popWindowMatrix();
}
else {
// here I did multiple tests (one by one):
// Test 1: treat the camera as a transform (took implementation from IntersectionVisitor::apply(osg::Transform&) )
if (!enter(*(camera.asTransform()))) return;
osg::ref_ptr<osg::RefMatrix> matrix = _modelStack.empty() ? new osg::RefMatrix() : new osg::RefMatrix(*_modelStack.back());
camera.computeLocalToWorldMatrix(*matrix,this);
pushModelMatrix(matrix.get());
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
popModelMatrix();
// tidy up an cached cull variables in the current intersector.
leave();
// End of Test 1
// Test 2: treat the camera as a osg::Group only!
if (!enter(*(camera.asGroup()))) return;
traverse(*(camera.asGroup()));
leave();
// End of test 2
// Test 3: just try not to push the model matrix, view matrix, projection or viewport, one by one:
if (camera.getViewport()) pushWindowMatrix( camera.getViewport() );
pushProjectionMatrix( new osg::RefMatrix(camera.getProjectionMatrix()) );
pushViewMatrix( new osg::RefMatrix(camera.getViewMatrix()) );
//pushModelMatrix( new osg::RefMatrix() );
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
//popModelMatrix();
popViewMatrix();
popProjectionMatrix();
if (camera.getViewport()) popWindowMatrix();
// End of Test 3
}
}
.. But none of this tests gave interesting result :-(... I really don't know where this problem may comes from then, and I really need to be able to pick objects in a Camera containing other sub cameras :-S. Do you have any clue about all that ? What am I doing wrong ?
regards,
Manu.
I have an interesting issue here:
I'm building a scene this way (the following is a lua script using osgIntrospection to manipulate OSG stuff) :
local root = osg.Group()
root:setName("Universe")
-- we want to add this root object as a scene in the current project (otherwise it will never be found)
-- this root object will be assigned as the scenedata for the master camera.
local proj = vProj.ProjectManager.instance():getCurrent()
proj:add_Scene(root)
local view = vDisplay.DisplayManager.getViewer():getView(0) -- here, getViewer() returns our osgViewer::CompositeViewer object
local manip = reflection.cast(view:getCameraManipulator(),"vGA::ArcBallManipulator")
-- now create the LTS project:
require('LTS')
local cam = view:getCamera() -- this is the "main" camera, the scene data for this camera is the previously declared "root" object
local subcam = osg.Camera() -- we create a sub camera than we will add to the main scene (so an inderect child for the main camera...)
subcam:setGraphicsContext(cam:getGraphicsContext())
subcam:setViewport(cam:getViewport())
subcam:setRenderOrder(osg.Camera.RenderOrder.POST_RENDER,3) -- We post render this subcamera with an arbitrary order.
subcam:setClearMask(GL.Mode.GL_DEPTH_BUFFER_BIT) -- We want to render Universe scale scenes that's why we introduced this multi pass system.
root:addChild(subcam)
local st = vOGL.SceneTools;
local pat = osg.PositionAttitudeTransform()
pat:addChild(LTS.createDoubleCraft("K1")) -- Here we create a satellit object
subcam:addChild(pat) -- And we add the object to the sub camera...
... this scene is rendered perfectly... but now I'm trying to "pick" items in the scene using the implementation found in osgViewer::View::computeIntersections(...) : If I put my "K1" object directly "in" the "main" camera everything is perfect, and I can pick intersections correctly. But when using this "subcam" as parent then I get incorrect results :-( (intersections found when clicking on nothing, or no intersections found when cliking on sub parts of the object...)
I gave a look at the osgUtil::IntersectionVisitor implementation... and I think everything is happening in this function:
void IntersectionVisitor::apply(osg::Camera& camera)
{
// osg::notify(osg::NOTICE)<<"apply(Camera&)"<<std::endl;
// note, commenting out right now because default Camera setup is with the culling active. Should this be changed?
// if (!enter(camera)) return;
// osg::notify(osg::NOTICE)<<"inside apply(Camera&)"<<std::endl;
if (camera.getViewport()) pushWindowMatrix( camera.getViewport() );
pushProjectionMatrix( new osg::RefMatrix(camera.getProjectionMatrix()) );
pushViewMatrix( new osg::RefMatrix(camera.getViewMatrix()) );
pushModelMatrix( new osg::RefMatrix() );
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
popModelMatrix();
popViewMatrix();
popProjectionMatrix();
if (camera.getViewport()) popWindowMatrix();
// leave();
}
I created my own "ExtendedIntersectorVisitor" (derived from this class) to override this function and I made multiple tests to handle the "main" camera and the "sub" cameras differently:
void ExtendedIntersectionVisitor::apply(osg::Camera & camera) {
if(!cameraInitialized) {
cameraInitialized = true;
// The first time we get a camera object we use it to setup the camera details normaly:
if (camera.getViewport()) pushWindowMatrix( camera.getViewport() );
pushProjectionMatrix( new osg::RefMatrix(camera.getProjectionMatrix()) );
pushViewMatrix( new osg::RefMatrix(camera.getViewMatrix()) );
pushModelMatrix( new osg::RefMatrix() );
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
popModelMatrix();
popViewMatrix();
popProjectionMatrix();
if (camera.getViewport()) popWindowMatrix();
}
else {
// here I did multiple tests (one by one):
// Test 1: treat the camera as a transform (took implementation from IntersectionVisitor::apply(osg::Transform&) )
if (!enter(*(camera.asTransform()))) return;
osg::ref_ptr<osg::RefMatrix> matrix = _modelStack.empty() ? new osg::RefMatrix() : new osg::RefMatrix(*_modelStack.back());
camera.computeLocalToWorldMatrix(*matrix,this);
pushModelMatrix(matrix.get());
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
popModelMatrix();
// tidy up an cached cull variables in the current intersector.
leave();
// End of Test 1
// Test 2: treat the camera as a osg::Group only!
if (!enter(*(camera.asGroup()))) return;
traverse(*(camera.asGroup()));
leave();
// End of test 2
// Test 3: just try not to push the model matrix, view matrix, projection or viewport, one by one:
if (camera.getViewport()) pushWindowMatrix( camera.getViewport() );
pushProjectionMatrix( new osg::RefMatrix(camera.getProjectionMatrix()) );
pushViewMatrix( new osg::RefMatrix(camera.getViewMatrix()) );
//pushModelMatrix( new osg::RefMatrix() );
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
//popModelMatrix();
popViewMatrix();
popProjectionMatrix();
if (camera.getViewport()) popWindowMatrix();
// End of Test 3
}
}
.. But none of this tests gave interesting result :-(... I really don't know where this problem may comes from then, and I really need to be able to pick objects in a Camera containing other sub cameras :-S. Do you have any clue about all that ? What am I doing wrong ?
regards,
Manu.
Emmanuel Roche
Sep 23, 2008, 7:07:07 AM9/23/08
to OSG Users
Okay, more information on this issue I mentioned:
I tested a scene where I have only two satellites (not too far away, the same size) in two different sub camera (still under the main camera): in that case, using the "Test 2" implementation [treating the camera as a simple Group] gives correct picking results.
So now, I think the second part of the problem I have in my "normal" scene is due to the scale difference between the objects: in the main camera, I have a subcamera containing an "Earth" model (radius ~= 6371 units, since I use km as unit) and in an other subcamera I have my satellite (typical size ~= 0.001 units as the satellite has a small size in meters...)
using the subcam:setClearMask(GL.Mode.GL_DEPTH_BUFFER_BIT) statement is enough to display everything correctly even with those geant scale differences [actually I also have a "Sun" object in an other subcamera with real size (695 500 units :-( ), and real distance from the earth (150 000 000 units !!! ) :-S ]... maybe this can lead to an overflow of the precision when performing the intersection tests ??? do those tests use floats or doubles ?
regards,
Manu.
I tested a scene where I have only two satellites (not too far away, the same size) in two different sub camera (still under the main camera): in that case, using the "Test 2" implementation [treating the camera as a simple Group] gives correct picking results.
So now, I think the second part of the problem I have in my "normal" scene is due to the scale difference between the objects: in the main camera, I have a subcamera containing an "Earth" model (radius ~= 6371 units, since I use km as unit) and in an other subcamera I have my satellite (typical size ~= 0.001 units as the satellite has a small size in meters...)
using the subcam:setClearMask(GL.Mode.GL_DEPTH_BUFFER_BIT) statement is enough to display everything correctly even with those geant scale differences [actually I also have a "Sun" object in an other subcamera with real size (695 500 units :-( ), and real distance from the earth (150 000 000 units !!! ) :-S ]... maybe this can lead to an overflow of the precision when performing the intersection tests ??? do those tests use floats or doubles ?
regards,
Manu.
2008/9/23 Emmanuel Roche <roche.e...@gmail.com>
Emmanuel Roche
Sep 23, 2008, 12:42:30 PM9/23/08
to OSG Users
Hello again...
I did other tests, my idea was:
I have a single main camera displaying a root object [an osg::Group] and this root object contains 5 or 6 osg::Camera object as direct children. And those "sub cameras" contain pieces of the scene I want to display. Since (I don't know why, but) using an IntersectVisitor gives completely incorrect result on the main camera in that case, I decided to use my intersectionvisitor with each sub camera one by one... in that case everything should behave as if each of my sub camera was the root object when it's traversed, no ?... but the answer is: NO... :-( this case doesn't seem to be the same as using a single camera containing objects as the intersection results are still completely false
So my big question is now : what's the difference (from a "camera point of view when it comes to intersections") between view->setSceneData(node) and camera->addChild(node) ??? I keep investigating... :-) but any shortcut would really be appreciated :-).
regards,
Manu.
PS: here is the main part of the code concerning the previous idea I mentioned if someone wants to have a look...
osg::Camera* cam = view->getCamera();
osg::Matrixd vm;
osg::Matrixd pm;
osg::ref_ptr<osg::Viewport> vp;
osgUtil::LineSegmentIntersector::Intersections hits;
vDisplay::DisplayManager::CameraDeq& cams = vDisplay::DisplayManager::getRegisteredCameras(view);
for(vDisplay::DisplayManager::CameraDeq::iterator it = cams.begin(); it != cams.end(); ++it) {
osgUtil::LineSegmentIntersector::CoordinateFrame cf = osgUtil::Intersector::PROJECTION; //(*it)->getViewport() ? osgUtil::Intersector::WINDOW : osgUtil::Intersector::PROJECTION;
osg::ref_ptr< osgUtil::LineSegmentIntersector > picker = new osgUtil::LineSegmentIntersector(cf, x, y);
//osgUtil::IntersectionVisitor iv(picker.get());
vOGL::ExtendedIntersectionVisitor iv(picker.get());
iv.setTraversalMask(0xFFFFFFFF);
// Reconfigure the camera:
vm = (*it)->getViewMatrix(); // these are actually identity matrices as only the main camera is manipulated....
pm = (*it)->getProjectionMatrix();
vp = (*it)->getViewport();
(*it)->setViewMatrix(cam->getViewMatrix());
(*it)->setProjectionMatrix(cam->getProjectionMatrix());
(*it)->setViewport(cam->getViewport());
if ((*it)->getViewport()) iv.pushWindowMatrix( (*it)->getViewport() );
iv.pushProjectionMatrix( new osg::RefMatrix((*it)->getProjectionMatrix()) );
iv.pushViewMatrix( new osg::RefMatrix((*it)->getViewMatrix()) );
iv.pushModelMatrix( new osg::RefMatrix() );
(*it)->accept(iv);
iv.popModelMatrix();
iv.popViewMatrix();
iv.popProjectionMatrix();
if ((*it)->getViewport()) iv.popWindowMatrix();
(*it)->setViewMatrix(vm);
(*it)->setProjectionMatrix(pm);
(*it)->setViewport(vp.get());
if (picker->containsIntersections())
{
hits = picker->getIntersections();
vLog::logInfo("Got %d intersections",hits.size());
return true;
}
}
I did other tests, my idea was:
I have a single main camera displaying a root object [an osg::Group] and this root object contains 5 or 6 osg::Camera object as direct children. And those "sub cameras" contain pieces of the scene I want to display. Since (I don't know why, but) using an IntersectVisitor gives completely incorrect result on the main camera in that case, I decided to use my intersectionvisitor with each sub camera one by one... in that case everything should behave as if each of my sub camera was the root object when it's traversed, no ?... but the answer is: NO... :-( this case doesn't seem to be the same as using a single camera containing objects as the intersection results are still completely false
So my big question is now : what's the difference (from a "camera point of view when it comes to intersections") between view->setSceneData(node) and camera->addChild(node) ??? I keep investigating... :-) but any shortcut would really be appreciated :-).
regards,
Manu.
PS: here is the main part of the code concerning the previous idea I mentioned if someone wants to have a look...
osg::Camera* cam = view->getCamera();
osg::Matrixd vm;
osg::Matrixd pm;
osg::ref_ptr<osg::Viewport> vp;
osgUtil::LineSegmentIntersector::Intersections hits;
vDisplay::DisplayManager::CameraDeq& cams = vDisplay::DisplayManager::getRegisteredCameras(view);
for(vDisplay::DisplayManager::CameraDeq::iterator it = cams.begin(); it != cams.end(); ++it) {
osgUtil::LineSegmentIntersector::CoordinateFrame cf = osgUtil::Intersector::PROJECTION; //(*it)->getViewport() ? osgUtil::Intersector::WINDOW : osgUtil::Intersector::PROJECTION;
osg::ref_ptr< osgUtil::LineSegmentIntersector > picker = new osgUtil::LineSegmentIntersector(cf, x, y);
//osgUtil::IntersectionVisitor iv(picker.get());
vOGL::ExtendedIntersectionVisitor iv(picker.get());
iv.setTraversalMask(0xFFFFFFFF);
// Reconfigure the camera:
vm = (*it)->getViewMatrix(); // these are actually identity matrices as only the main camera is manipulated....
pm = (*it)->getProjectionMatrix();
vp = (*it)->getViewport();
(*it)->setViewMatrix(cam->getViewMatrix());
(*it)->setProjectionMatrix(cam->getProjectionMatrix());
(*it)->setViewport(cam->getViewport());
if ((*it)->getViewport()) iv.pushWindowMatrix( (*it)->getViewport() );
iv.pushProjectionMatrix( new osg::RefMatrix((*it)->getProjectionMatrix()) );
iv.pushViewMatrix( new osg::RefMatrix((*it)->getViewMatrix()) );
iv.pushModelMatrix( new osg::RefMatrix() );
(*it)->accept(iv);
iv.popModelMatrix();
iv.popViewMatrix();
iv.popProjectionMatrix();
if ((*it)->getViewport()) iv.popWindowMatrix();
(*it)->setViewMatrix(vm);
(*it)->setProjectionMatrix(pm);
(*it)->setViewport(vp.get());
if (picker->containsIntersections())
{
hits = picker->getIntersections();
vLog::logInfo("Got %d intersections",hits.size());
return true;
}
}
2008/9/23 Emmanuel Roche <roche.e...@gmail.com>
Robert Osfield
Sep 23, 2008, 12:48:54 PM9/23/08
to OpenSceneGraph Users
Hi Manu,
I don't have the head for complex emails or logic right now, so I
won't five into the details of thread. What does jump out from speed
reading this email is why you don't use osgViewer::CompositeViewer
with multipler Views as this would totally clear up an ambiguity about
what camera each intersection test is made against.
Robert.
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Emmanuel Roche
Sep 23, 2008, 1:06:03 PM9/23/08
to OpenSceneGraph Users
Hi Robert,
unfortunately I don't think this an available option in my current project: our software is already relying quite heavily on our current CompositteViewer / View structure (a view per window [using wxWidgets], a camera manipulator, a single scene graph that should not be cut into pieces, etc... and any way, I think there is a real problem here (expect if there is still something I missed) so I think for me (in both cases) it's important to solve this issue instead of just bypassing it.
I hope you will find some time to give a deeper look to this thread later ;-), meanwhile I'm not giving up: I checked the setSceneData(node) methods and it's basically the same just a camera->addChild(node) call... so I may have the finger on something [as I expected a noticable difference]. I'll keep you informed.
regards,
Manu.
unfortunately I don't think this an available option in my current project: our software is already relying quite heavily on our current CompositteViewer / View structure (a view per window [using wxWidgets], a camera manipulator, a single scene graph that should not be cut into pieces, etc... and any way, I think there is a real problem here (expect if there is still something I missed) so I think for me (in both cases) it's important to solve this issue instead of just bypassing it.
I hope you will find some time to give a deeper look to this thread later ;-), meanwhile I'm not giving up: I checked the setSceneData(node) methods and it's basically the same just a camera->addChild(node) call... so I may have the finger on something [as I expected a noticable difference]. I'll keep you informed.
regards,
Manu.
2008/9/23 Robert Osfield <robert....@gmail.com>
Emmanuel Roche
Sep 23, 2008, 5:43:30 PM9/23/08
to OpenSceneGraph Users
Okay...
I think I tried everything I could think about, unsuccessfully... unfortunately, I'm currently on WinXP with Visual Studio and for some obscure reason, I just cannot get/use the debug symbols from some of the OSG libraries (maybe beacuse I'm accessing those functions introspectively though a Lua release binary ? not sure about all that...) an as a result I cannot go deeper into those tests :-(
But I've just discovered a new fact: this is at least partially linked to the scale of my object, I tried the following scene graph:
- the main View camera
- my root group
- a sub camera
- a PositionAttitudeTransform (with a scale set)
- an object
---> then depending on the scale applied in the PositionAttitudeTransform I can pick parts of my object or not : the bigger the scale, the closer to the object I need to be to get some intersections (and I'm not even sure those intersections are correct...). So could there be a scale factor not applied somewhere ?? Or maybe, since my main camera renders no objects its near/far planes are set to minimal values and then those settings are not modified accordingly when going though a sub camera in an intersectionVisitor [this could explain why I cannot select objects if I'm not very very close to them (and depending on their scale)...] ?
Is there an other way to render Univers scale + high precision scenes without using multiple cameras as children ??? I did a quick test using ClearNodes and setting the only camera left to "DO_NOT_COMPUTE_NEAR_FAR", but the results are not good (it seems to me that the ClearNodes clear the color buffer even when I only set the DEPTH_BUFFER_BIT mask... I really don't get it...).
regards,
Manu.
I think I tried everything I could think about, unsuccessfully... unfortunately, I'm currently on WinXP with Visual Studio and for some obscure reason, I just cannot get/use the debug symbols from some of the OSG libraries (maybe beacuse I'm accessing those functions introspectively though a Lua release binary ? not sure about all that...) an as a result I cannot go deeper into those tests :-(
But I've just discovered a new fact: this is at least partially linked to the scale of my object, I tried the following scene graph:
- the main View camera
- my root group
- a sub camera
- a PositionAttitudeTransform (with a scale set)
- an object
---> then depending on the scale applied in the PositionAttitudeTransform I can pick parts of my object or not : the bigger the scale, the closer to the object I need to be to get some intersections (and I'm not even sure those intersections are correct...). So could there be a scale factor not applied somewhere ?? Or maybe, since my main camera renders no objects its near/far planes are set to minimal values and then those settings are not modified accordingly when going though a sub camera in an intersectionVisitor [this could explain why I cannot select objects if I'm not very very close to them (and depending on their scale)...] ?
Is there an other way to render Univers scale + high precision scenes without using multiple cameras as children ??? I did a quick test using ClearNodes and setting the only camera left to "DO_NOT_COMPUTE_NEAR_FAR", but the results are not good (it seems to me that the ClearNodes clear the color buffer even when I only set the DEPTH_BUFFER_BIT mask... I really don't get it...).
regards,
Manu.
Emmanuel Roche
Sep 23, 2008, 5:51:50 PM9/23/08
to OpenSceneGraph Users
Oh, and by the way, the results seem to be exactly the same when I use the osgUtil::IntersectVisitor instead of the new version... so, someone has a clue ?
Emmanuel Roche
Sep 24, 2008, 4:50:19 AM9/24/08
to OpenSceneGraph Users
:-(... I'm really going to cry now...
Guys, I tried something else and I feel like I'm loosing my mind:
Since I cannot pick anything when traversing a sub camera, I tried to build my scene this way:
- the main View camera (with cull mask set to 0x1)
- my root group
- a sub camera (with node mask set to 0x1)
Guys, I tried something else and I feel like I'm loosing my mind:
Since I cannot pick anything when traversing a sub camera, I tried to build my scene this way:
- the main View camera (with cull mask set to 0x1)
- my root group
- a sub camera (with node mask set to 0x1)
- a PositionAttitudeTransform (with a scale set)
- an object
- An hidden group (with node mask set to 0x100)
- a link to the SAME previous PositionAttitudeTransform object.
... With that I still have a proper display (the default node mask is 0xFFFFFFFF): only my sub camera is rendered and the hidden group is not visible as expected.
then for my IntersectionVisitor I obviously use the traversal mask 0x100 : this way I was expecting to traverse my main camera and the hidden group, but none of the sub camera... and guess what ? It's just not working !!!! :-( It works if I don't hide my hidden group (giving it a node mask of 0x101, but of course this doesn't make sense considering the goal I have....)... So the IntersectionVisitor traversal also depends on the cull mask or something like that ? I could really use some explanations on that...
By the way I'm using OSG 2.6...
- a link to the SAME previous PositionAttitudeTransform object.
... With that I still have a proper display (the default node mask is 0xFFFFFFFF): only my sub camera is rendered and the hidden group is not visible as expected.
then for my IntersectionVisitor I obviously use the traversal mask 0x100 : this way I was expecting to traverse my main camera and the hidden group, but none of the sub camera... and guess what ? It's just not working !!!! :-( It works if I don't hide my hidden group (giving it a node mask of 0x101, but of course this doesn't make sense considering the goal I have....)... So the IntersectionVisitor traversal also depends on the cull mask or something like that ? I could really use some explanations on that...
By the way I'm using OSG 2.6...
Emmanuel Roche
Sep 24, 2008, 8:37:38 AM9/24/08
to OpenSceneGraph Users
Some more news:
I reverted to OSG 2.2 (I have the same problems with that version), and retrieved a full debug support, first I'm trying to solve the latest problem I faced (with the hidden node described in my previous mail), I'm using a scene like that:
- Main camera
- Root group
- Hidden group
- Position Attitude Transform
- Geode (with a sphere geometry inside).
- On the main camera I use a cull mask of 0x1
- on the Hidden group I switch between node mask 0x100 [not visible] and 0x101 [visible]
- And my intersectionVisitor still uses the traversal mask 0x100
I went through all the process step by step (now that I retrieved my debug support, thanks god :-) !!!), and the conclusion I have for the moment is:
--> This is all a Projection Matrix story !!!!
-> In the BAD case (when I hide the "hidden group") my proj matrix has a certain value when I start the call view->computeIntersection(x,y,hits,mask) and this matrix is used in the push_clone() function in IntersectionVisitor::apply(osg::Camera&) to create a cloned Intersector (and thus this new LineSegmentIntersector gets an incorrect _start vector and the call IntersectionVisitor::enter(osg::Node&) fails when trying to enter the "Root group", and no intersection is found !).
Now, I tried to put a breakpoint on both Camera::setProjectionMatrix(osg::Matrixf/d& ) as this seems to be the only "entry point" to modify a camera projection matrix... But I just CAN'T get on the point when the good camera projection is correctly set !!! is that done some other way ??? I keep investigating, I have no choice any way...
regards,
Manu.
I reverted to OSG 2.2 (I have the same problems with that version), and retrieved a full debug support, first I'm trying to solve the latest problem I faced (with the hidden node described in my previous mail), I'm using a scene like that:
- Main camera
- Root group
- Hidden group
- Position Attitude Transform
- Geode (with a sphere geometry inside).
- On the main camera I use a cull mask of 0x1
- on the Hidden group I switch between node mask 0x100 [not visible] and 0x101 [visible]
- And my intersectionVisitor still uses the traversal mask 0x100
I went through all the process step by step (now that I retrieved my debug support, thanks god :-) !!!), and the conclusion I have for the moment is:
--> This is all a Projection Matrix story !!!!
-> In the BAD case (when I hide the "hidden group") my proj matrix has a certain value when I start the call view->computeIntersection(x,y,hits,mask) and this matrix is used in the push_clone() function in IntersectionVisitor::apply(osg::Camera&) to create a cloned Intersector (and thus this new LineSegmentIntersector gets an incorrect _start vector and the call IntersectionVisitor::enter(osg::Node&) fails when trying to enter the "Root group", and no intersection is found !).
Now, I tried to put a breakpoint on both Camera::setProjectionMatrix(osg::Matrixf/d& ) as this seems to be the only "entry point" to modify a camera projection matrix... But I just CAN'T get on the point when the good camera projection is correctly set !!! is that done some other way ??? I keep investigating, I have no choice any way...
regards,
Manu.
2008/9/24 Emmanuel Roche <roche.e...@gmail.com>
Emmanuel Roche
Sep 24, 2008, 9:28:41 AM9/24/08
to OpenSceneGraph Users
Okay, I think I have something here:
I started from my first call on my CompositeViewer::frame()
then we get in renderingTraversals() --> runOperations() [for the Contexts] --> renderer::cull_draw() ---> SceneView::cull() and here we have:
_cullVisitor->setTraversalMask(_cullMask);
bool computeNearFar = cullStage(getProjectionMatrix(),getViewMatrix(),_cullVisitor.get(),_rendergraph.get(),_renderStage.get());
if (computeNearFar)
{
CullVisitor::value_type zNear = _cullVisitor->getCalculatedNearPlane();
CullVisitor::value_type zFar = _cullVisitor->getCalculatedFarPlane();
_cullVisitor->clampProjectionMatrix(getProjectionMatrix(),zNear,zFar);
}
And that's where my latest problem comes from !!! This cull visitor uses the Cull mask to somehow update the projection matrix... (and sorry, I put breakpoint on setProjectionMatrix(...) but not on getProjectionMatrix() :-( I didn't notice the reference this function returns...).
And if I'm lucking this may also explain why everything is messed up when I use sub cameras: the sub camera graph don't get into this cullstage for the main camera, do they ? and if not, the main projection gets corrupted the same way and then since the "Root group" is not entered, the sub cameras are not reached any way (or they can be sometimes because of those corrupted projections) !!! So everything is clear now :-D [I've just made a simple check with a sub camera instead of an hidden group].
Now that the problem is clarified, the big question is: What's the best option to achieve the desired behavior (hide a node and still be able to intersect with it, or use sub cameras) ???
I hope this little monologue may help other people stuck on that issue too (if any :-) )
I started from my first call on my CompositeViewer::frame()
then we get in renderingTraversals() --> runOperations() [for the Contexts] --> renderer::cull_draw() ---> SceneView::cull() and here we have:
_cullVisitor->setTraversalMask(_cullMask);
bool computeNearFar = cullStage(getProjectionMatrix(),getViewMatrix(),_cullVisitor.get(),_rendergraph.get(),_renderStage.get());
if (computeNearFar)
{
CullVisitor::value_type zNear = _cullVisitor->getCalculatedNearPlane();
CullVisitor::value_type zFar = _cullVisitor->getCalculatedFarPlane();
_cullVisitor->clampProjectionMatrix(getProjectionMatrix(),zNear,zFar);
}
And that's where my latest problem comes from !!! This cull visitor uses the Cull mask to somehow update the projection matrix... (and sorry, I put breakpoint on setProjectionMatrix(...) but not on getProjectionMatrix() :-( I didn't notice the reference this function returns...).
And if I'm lucking this may also explain why everything is messed up when I use sub cameras: the sub camera graph don't get into this cullstage for the main camera, do they ? and if not, the main projection gets corrupted the same way and then since the "Root group" is not entered, the sub cameras are not reached any way (or they can be sometimes because of those corrupted projections) !!! So everything is clear now :-D [I've just made a simple check with a sub camera instead of an hidden group].
Now that the problem is clarified, the big question is: What's the best option to achieve the desired behavior (hide a node and still be able to intersect with it, or use sub cameras) ???
I hope this little monologue may help other people stuck on that issue too (if any :-) )
Emmanuel Roche
Sep 24, 2008, 11:19:37 AM9/24/08
to OSG Users
Now, a conclusion on this thread: here is how I solved that issue: I'm "registering" all the cameras where I have contain to intersect with, and then I take them one by one to perform an intersection test, but you need to modify the view amtrix, projection matrix and viewport (using those from the main camera), and then I use a modified IntersectionVisitor to "correct" the projection matrix before entering a camera. So here it the most important code parts if someone is interested in introducing that in the core OSG libs one day (sorry I'm really late on my job, so I don't have time for a submission right now :-( ).
main function to do some intersection tests:
bool Tools::handleViewIntersections(osgViewer::View * view, double x, double y)
{
// Bouml preserved body begin 00043B04
if(!view) {
vLog::logError("invalid view object in tools::handleViewIntersections()");
return false;
}
osgUtil::LineSegmentIntersector::Intersections hits;
float local_x, local_y = 0.0;
view->getCameraContainingPosition(x, y, local_x, local_y);
osg::Camera* camera = view->getCamera();
osg::Matrixd pm,vm;
main function to do some intersection tests:
bool Tools::handleViewIntersections(osgViewer::View * view, double x, double y)
{
// Bouml preserved body begin 00043B04
if(!view) {
vLog::logError("invalid view object in tools::handleViewIntersections()");
return false;
}
osgUtil::LineSegmentIntersector::Intersections hits;
float local_x, local_y = 0.0;
view->getCameraContainingPosition(x, y, local_x, local_y);
osg::Camera* camera = view->getCamera();
osg::Matrixd pm,vm;
osg::ref_ptr<osg::Viewport> vp;
osgUtil::LineSegmentIntersector::CoordinateFrame cf = camera->getViewport() ? osgUtil::Intersector::WINDOW : osgUtil::Intersector::PROJECTION;
osg::ref_ptr< osgUtil::LineSegmentIntersector > picker = new osgUtil::LineSegmentIntersector(cf, local_x, local_y);
osg::ref_ptr< osgUtil::LineSegmentIntersector > picker = new osgUtil::LineSegmentIntersector(cf, local_x, local_y);
vDisplay::DisplayManager::CameraDeq& cams = vDisplay::DisplayManager::getRegisteredCameras(view);
for(vDisplay::DisplayManager::CameraDeq::iterator it = cams.begin(); it != cams.end(); ++it) {
//osgUtil::IntersectionVisitor iv(picker.get());
vOGL::ExtendedIntersectionVisitor iv(picker.get());
vOGL::ExtendedIntersectionVisitor iv(picker.get());
iv.setFrameStamp(vDisplay::DisplayManager::getViewer()->getFrameStamp());
iv.setTraversalMask(vOGL::PICKABLE);
vm = (*it)->getViewMatrix();
iv.setTraversalMask(vOGL::PICKABLE);
vm = (*it)->getViewMatrix();
pm = (*it)->getProjectionMatrix();
vp = (*it)->getViewport();
(*it)->setViewMatrix(camera->getViewMatrix());
(*it)->setProjectionMatrix(camera->getProjectionMatrix());
(*it)->setViewport(camera->getViewport());
(*it)->accept(iv);
(*it)->setProjectionMatrix(camera->getProjectionMatrix());
(*it)->setViewport(camera->getViewport());
(*it)->accept(iv);
(*it)->setViewMatrix(vm);
(*it)->setProjectionMatrix(pm);
(*it)->setViewport(vp.get());
if (picker->containsIntersections())
{
hits = picker->getIntersections();
vLog::logInfo("Got %d intersections",hits.size());
return true;
}
}
vLog::logInfo("Got 0 intersections");
return false;
// Bouml preserved body end 00043B04
}
the modified function in my ExtendedIntersectionVisitor:
return false;
// Bouml preserved body end 00043B04
}
the modified function in my ExtendedIntersectionVisitor:
void ExtendedIntersectionVisitor::apply(osg::Camera & camera) {
// Bouml preserved body begin 00043C84
// Use a simplified cull traversal here to correct the projection:
osg::RenderInfo _renderInfo;
_renderInfo.setState(new osg::State);
_renderInfo.setView(camera.getView());
osg::ref_ptr<osgUtil::CullVisitor> cv = osgUtil::CullVisitor::create();
cv->setTraversalMask(getTraversalMask()); // Use the same mask to retrieve the good extend of the pickable objects.
osg::ref_ptr<osgUtil::RenderStage> renderStage = new osgUtil::RenderStage();
osg::ref_ptr<osgUtil::StateGraph> rendergraph = new osgUtil::StateGraph();
cv->setStateGraph(rendergraph.get());
cv->setRenderStage(renderStage.get());
cv->reset();
cv->setFrameStamp(const_cast<osg::FrameStamp*>(getFrameStamp()));
if (getFrameStamp())
{
cv->setTraversalNumber(getFrameStamp()->getFrameNumber());
}
//cv->inheritCullSettings(*this);
cv->setClearNode(NULL); // reset earth sky on each frame.
cv->setStateGraph(rendergraph.get());
cv->setRenderStage(renderStage.get());
cv->setRenderInfo( _renderInfo );
renderStage->reset();
rendergraph->clean();
renderStage->setViewport(camera.getViewport());
renderStage->setClearColor(camera.getClearColor());
renderStage->setClearMask(camera.getClearMask());
renderStage->setCamera(&camera);
cv->pushViewport(camera.getViewport());
cv->pushProjectionMatrix(new osg::RefMatrix(camera.getProjectionMatrix()));
cv->pushModelViewMatrix(new osg::RefMatrix(camera.getViewMatrix()),osg::Transform::ABSOLUTE_RF);
for(unsigned int childNo=0;
childNo<camera.getNumChildren();
++childNo)
{
camera.getChild(childNo)->accept(*cv);
}
cv->popModelViewMatrix();
cv->popProjectionMatrix();
cv->popViewport();
renderStage->sort();
rendergraph->prune();
// Projection correction:
osg::Matrixd proj = camera.getProjectionMatrix();
osgUtil::CullVisitor::value_type zNear = cv->getCalculatedNearPlane();
osgUtil::CullVisitor::value_type zFar = cv->getCalculatedFarPlane();
cv->clampProjectionMatrix(proj,zNear,zFar);
// Normal process:
// Use a simplified cull traversal here to correct the projection:
osg::RenderInfo _renderInfo;
_renderInfo.setState(new osg::State);
_renderInfo.setView(camera.getView());
osg::ref_ptr<osgUtil::CullVisitor> cv = osgUtil::CullVisitor::create();
cv->setTraversalMask(getTraversalMask()); // Use the same mask to retrieve the good extend of the pickable objects.
osg::ref_ptr<osgUtil::RenderStage> renderStage = new osgUtil::RenderStage();
osg::ref_ptr<osgUtil::StateGraph> rendergraph = new osgUtil::StateGraph();
cv->setStateGraph(rendergraph.get());
cv->setRenderStage(renderStage.get());
cv->reset();
cv->setFrameStamp(const_cast<osg::FrameStamp*>(getFrameStamp()));
if (getFrameStamp())
{
cv->setTraversalNumber(getFrameStamp()->getFrameNumber());
}
//cv->inheritCullSettings(*this);
cv->setClearNode(NULL); // reset earth sky on each frame.
cv->setStateGraph(rendergraph.get());
cv->setRenderStage(renderStage.get());
cv->setRenderInfo( _renderInfo );
renderStage->reset();
rendergraph->clean();
renderStage->setViewport(camera.getViewport());
renderStage->setClearColor(camera.getClearColor());
renderStage->setClearMask(camera.getClearMask());
renderStage->setCamera(&camera);
cv->pushViewport(camera.getViewport());
cv->pushProjectionMatrix(new osg::RefMatrix(camera.getProjectionMatrix()));
cv->pushModelViewMatrix(new osg::RefMatrix(camera.getViewMatrix()),osg::Transform::ABSOLUTE_RF);
for(unsigned int childNo=0;
childNo<camera.getNumChildren();
++childNo)
{
camera.getChild(childNo)->accept(*cv);
}
cv->popModelViewMatrix();
cv->popProjectionMatrix();
cv->popViewport();
renderStage->sort();
rendergraph->prune();
// Projection correction:
osg::Matrixd proj = camera.getProjectionMatrix();
osgUtil::CullVisitor::value_type zNear = cv->getCalculatedNearPlane();
osgUtil::CullVisitor::value_type zFar = cv->getCalculatedFarPlane();
cv->clampProjectionMatrix(proj,zNear,zFar);
// Normal process:
if (camera.getViewport()) pushWindowMatrix( camera.getViewport() );
pushProjectionMatrix( new osg::RefMatrix(proj) );
pushViewMatrix( new osg::RefMatrix(camera.getViewMatrix()) );
pushModelMatrix( new osg::RefMatrix() );
// now push an new intersector clone transform to the new local coordinates
push_clone();
traverse(camera);
// pop the clone.
pop_clone();
popModelMatrix();
popViewMatrix();
popProjectionMatrix();
if (camera.getViewport()) popWindowMatrix();
// Bouml preserved body end 00043C84
}
... I'm not sure we need to setup the CullVisitor so much : but I just took most of the implementation from SceneView::cullstate(...) and it's working like that... and as I said, I'm in an hurry now :-)
regards,
Manu.
}
... I'm not sure we need to setup the CullVisitor so much : but I just took most of the implementation from SceneView::cullstate(...) and it's working like that... and as I said, I'm in an hurry now :-)
regards,
Manu.
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