Re: [osg-users] Atomic Global Mutex, comments?
On Sat, Dec 18, 2010 at 2:27 AM, David Fries da...@fries.net wrote:
Computers are coming out with more and more cores which will only
increase the number of threads in use. Currently OpenSceneGraph has a
bottleneck in scene graph operations limiting the performance of
multithreaded programs, even when they are operating on completely
separate nodes as the Drawable, Node, and StateAttribute addParent and
removeParent all contend on one global mutex.
OpenThreads::Mutex* getRefMutex() const { return
getGlobalReferencedMutex(); }
Thanks for looking into this. Some of us have recently been looking hard at
thread safety and performance issues in OSG.
The global referenced mutex is unfortunate, not least because its use is
buggy. I would facetiously call it a Writer lock; writers of the _parents
list lock it, but none of the readers do! So obviously this should be some
kind of ReaderWriter lock, but that has its own issues, not least of which
is that the OpenThreads ReaderWriterMutex implementation is suspected of
being buggy, if I recall correctly.
So, I don't know what to say about your Atomic Global Mutex work. My own
feeling is that something like Linux' RCU list
(http://en.wikipedia.org/wiki/Read-copy-update), which would eliminate most
of not all of the synchronization on the parent list, is a better approach.
This is even more true if the global mutex were being used correctly :)
Tim
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Re: [osg-users] [3rdparty] Rendering into cegui element
well i solved my problem to render into cegui elmement but i am facing another one plesae see the attached image [Image: http://img811.imageshack.us/img811/7510/screenah.jpg ] please note the cegui listbox in the left here my code to create the textitems dynamically Code: AvionsListBox = m_pHUD-GetWidget(AvionsListBox); static_castCEGUI::Listbox*(AvionsListBox)-setMultiselectEnabled(false); ListboxTextItem * listBoxItem = new ListboxTextItem(Cessna 172-p, 1); listBoxItem-setSelectionBrushImage(WindowsLook, MultiListSelectionBrush); static_castCEGUI::Listbox*(AvionsListBox)-addItem(listBoxItem); listBoxItem = new ListboxTextItem(L39 - Albatros. ,2); listBoxItem-setSelectionBrushImage(WindowsLook, MultiListSelectionBrush); static_castCEGUI::Listbox*(AvionsListBox)-addItem(listBoxItem); this is something related to cegui definitivelly but since i got no support on their forum i ask here -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=34958#34958 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] Create Cylinder Around Line
Hi Ullrich, I followed the procedure suggested by you and it worked perfectly. However you mentioned that the procedure below But you should replace this with properly constructed geometry. I didn't quite follow what you meant by that. Also, I would like to save each individual geode (geometry) as an osg file to use later and not just load in this scene graph. Is there a way I can do that ? Looking forward to your suggestion. For a quick proof of concept and convenience you can use ShapeDrawables for the cylinders. But you should replace this with properly constructed geometry. That's only a rought outline of course. You may want to skip the NodeVisitor bit for starters and simply use a hard-coded list of start/end points. Thanks, Sanat -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=34959#34959 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] osgAnimation deform TangentSpace ( osgUtil::TangentSpaceGenerator ) for BumpMapping
Hi, I have a Normal Map for an animated Character. To my understanding, I need to transfrom the Tangent and BiNormal which I got from osgUtil::TangentSpaceGenerator with the osgAnimation::RigTransform( Implementation ), otherwise Bump Mapping will not look correct. The RigTransform computeNormal method should do the job. Is there a way to access RigTransfrom in RigGeometry and transform the additional VertexAttributes per update cycle ? Any other Ideas how I could properly calculate the TangentSpace ? Thank you! Cheers, ParticlePeter -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=34960#34960 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
Re: [osg-users] VertexBufferObject usage very slow...
Since you wrote you use gDebugger, please check if glDrawElements index buffers are taken from CPU or GPU memory. If its CPU mem then all should be clear... Wojtek Lewandowski -Original Message- From: Sean Spicer Sent: Friday, December 17, 2010 7:57 PM To: OpenSceneGraph Users Subject: Re: [osg-users] VertexBufferObject usage very slow... Robert, Some more data... Looks like we're drawing approx 100K tri-strips every frame. The glDrawElements call is the culprit...though I'm still baffled by why it is so much slower with VBOs than in immediate mode. Perhaps the drawing isn't sorted by VBO so that all of the triangles drawn from each VBO are draw in single bind call ? sean _ Sean Spicer Aqumin (www.aqumin.com) Office+1.713.781.2121 Mobile...+1.713.447.2706 Fax...+1.713.781.2123 On Fri, Dec 17, 2010 at 11:37 AM, Sean Spicer sean.spi...@aqumin.com wrote: Hi Robert, We are not updating the data frame-to-frame, which is why this is so baffling. I'm working through the issue with gDebugger now - if you don't have any suggestions off the top of your head, then I'll start digging and report back what I find, since I don't have time try and duplicate the issue outside our app. cheers, sean _ Sean Spicer Aqumin (www.aqumin.com) Office+1.713.781.2121 Mobile...+1.713.447.2706 Fax...+1.713.781.2123 On Fri, Dec 17, 2010 at 2:36 AM, Robert Osfield robert.osfi...@gmail.com wrote: reproduces the problem you are seeing? ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
[osg-users] Render to texture 3D
Hi,
I'm trying to make efficient fluid simulation with osg
I've just found this page :
http://www.mail-archive.com//msg05568.html
It look pretty great as my 1 camera per slice code is very CPU time consuming.
I develop a geometry shader that change gl_layer value per primitive.
It work so i change my texture my texture attachement to camera's FBO as follow:
Code:
for(int i=0;i_depth;i++){
//one cam per slice
_cameras[i]-attach( osg::Camera::COLOR_BUFFER,tex,0,i,false);
}
to
for(int i=0;i1;i++){
//one overalll camera
_cameras[0]-attach(
osg::Camera::COLOR_BUFFER,tex,0,osg::Camera::FACE_CONTROLLED_BY_GEOMETRY_SHADER);
}
But this change make a crash:
Code:
RenderStage::runCameraSetUp(), FBO setup failed, FBO status= 0x8da8
Any idea?
Thank you!
Cheers,
Julien[/code]
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Re: [osg-users] Atomic Global Mutex, comments?
On Sat, Dec 18, 2010 at 01:53:36PM +0100, Tim Moore wrote:
On Sat, Dec 18, 2010 at 2:27 AM, David Fries da...@fries.net wrote:
Computers are coming out with more and more cores which will only
increase the number of threads in use. Currently OpenSceneGraph has a
bottleneck in scene graph operations limiting the performance of
multithreaded programs, even when they are operating on completely
separate nodes as the Drawable, Node, and StateAttribute addParent and
removeParent all contend on one global mutex.
OpenThreads::Mutex* getRefMutex() const { return
getGlobalReferencedMutex(); }
Thanks for looking into this. Some of us have recently been looking hard at
thread safety and performance issues in OSG.
The global referenced mutex is unfortunate, not least because its use is
buggy. I would facetiously call it a Writer lock; writers of the _parents
list lock it, but none of the readers do! So obviously this should be some
kind of ReaderWriter lock, but that has its own issues, not least of which
is that the OpenThreads ReaderWriterMutex implementation is suspected of
being buggy, if I recall correctly.
So, I don't know what to say about your Atomic Global Mutex work. My own
feeling is that something like Linux' RCU list
(http://en.wikipedia.org/wiki/Read-copy-update), which would eliminate most
of not all of the synchronization on the parent list, is a better approach.
This is even more true if the global mutex were being used correctly :)
The kernel is in a unique position when it comes to RCU, in that it
does the scheduling and it can know that all users of the previous
structure are finished with it. There's also the question of does it
cause problems to be looking at the old set of parents when another
thread made and change.
--
David Fries da...@fries.net
http://fries.net/~david/ (PGP encryption key available)
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Re: [osg-users] [ANN] MS Kinect - official drivers available
Hi Jan, I agree. Here is the journal article I talkes about http://www.heise.de/open/meldung/Offizielle-Open-Source-Treiber-fuer-Kinect-1152510.html This is the article translated by google: http://translate.google.com/translate?u=http%3A%2F%2Fwww.heise.de%2Fopen%2Fmeldung%2FOffizielle-Open-Source-Treiber-fuer-Kinect-1152510.htmlsl=detl=enhl=deie=UTF-8 Does the non-openNI Driver work on win, Linux and Mac? Best regards, Torben -- Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=34964#34964 ___ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
