[osg-users] OSG and NVX_gpu_memory_info

[Garth D]

Hi Robert,

Thanks for having a look at things and for the suggestion.

On 30/09/15 17:35, Robert Osfield wrote:> HI Garth,
 > I'd use a RealizerOperation.  Have a look at the osgvolume example to an
 > example of using a RealizerOperation to get information from the graphics
 > context.

I was unfortunately unable to solve the problem. Here is what I tried:

I checked the osgvolume.cpp source for 3.2.1 and 3.4.0, but did not find 
a RealizerOperation in either.

I did notice that osgvolume does also use viewer.setRealizeOperation() 
for TestSupportOperation, defined earlier. Is this what you are 
referring to? Assuming yes: This is the way I was able to successfully 
query the information once only at the start of the program. 
Unfortunately I need to query the information periodically, ie. over the 
course of the program, rather than just at initialisation. Unless I am 
mistaken, the target of setRealizeOperation is only called the one time, 
on viewer realization. Is this right? If so: Is there a corresponding 
call that I can use to attach an osg::Operation or similar to in order 
to make the required calls periodically? If not: Is there a way to 
indicate that the operation should be repeatedly called?

Or is there another part of osgvolume.cpp that I should be looking at? 
The only glGet* call in the file is in TestSupportOperation, which is 
set using setRealizeOperation(), so I think I am looking in the right place?

I'll continue to experiment. Thanks again for the suggestion. Is there 
anything else I should try?

Cheers,
Garth

 >
 > Robert.
 >
 > On 30 September 2015 at 03:49, Garth D <garthy_gso at entropicsoftware.com>
 > wrote:
 >
 >> Hi all,
 >>
 >> I was wondering if anyone has been successful in using the
 >> NVX_gpu_memory_info extension with OpenSceneGraph, and the best place to
 >> call glGetIntegerv to get the associated values.
 >>
 >> Details on the extension here:
 >> https://www.opengl.org/registry/specs/NVX/gpu_memory_info.txt
 >>
 >> I'm using Linux, OSG 3.2.1, and a card that supports the
 >> NVX_gpu_memory_info extension.
 >>
 >> I have tried querying the current and total memory using
 >> GPU_MEMORY_INFO_TOTAL_AVAILABLE_MEMORY_NVX and
 >> GPU_MEMORY_INFO_CURRENT_AVAILABLE_VIDMEM_NVX, and in each case but 
one, the
 >> values reported back are zero.
 >>
 >> The only success I have had thus far has been querying the values via an
 >> osg::Operation set with ViewerBase::setRealizeOperation() on my viewer
 >> (osg::Viewer). The values returned appear to be correct. This allows 
me to
 >> get the correct values *once* at the start of the program. 
Unfortunately I
 >> need to query them periodically, and I have been unable to do this.
 >>
 >> So far, I have tried hooking the calls into:
 >> - An osg::Camera::DrawHandler, set via
 >> osg::Camera::setInitialDrawCallback().
 >> - An osg::Node::NodeHandler, hooked into the root node via
 >> osg::Node::setUpdateCallback.
 >> - An osg::Drawable::DrawCallback, hooked into a dummy chain off the root
 >> of: osg::Node -> osg::Geode -> osg::Geometry (osg::Drawable), via
 >> osg::Drawable::setDrawCallback.
 >> - An osg::Drawable::CullCallback , hooked into a dummy chain off the 
root
 >> of: osg::Node -> osg::Geode -> osg::Geometry (osg::Drawable), via
 >> osg::Drawable::setCullCallback.
 >> - An osg::Camera::DrawHandler, set via
 >> osg::Camera::setFinalDrawCallback(). Only partly-tested due to a
 >> race-condition that occurs in my code, but appears to fail.
 >>
 >> I have experimented with osg::GraphicsContext::makeCurrent() with each.
 >>
 >> Can anyone suggest a better place to hook these calls into? Or
 >> alternatively confirm that they have the extension working with one 
of the
 >> above, so I can change or experiment with my existing setup to try 
to make
 >> it work?
 >>
 >> Cheers,
 >> Garth
 >> _______________________________________________
 >> osg-users mailing list
 >> osg-users at lists.openscenegraph.org
 >> 
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
 >>
 >
 >
 >
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