Hello Robert,

the first issue that I mentioned, and the sefault of the attempted fix, can be reproduced by slightly adapting the osgprerender.cpp example (attached). I set the texture filtering to something mipmap-ish:

...
texture2D->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR_MIPMAP_NEAREST );
texture2D->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
...

When zooming out, one of the lower mipmap layers becomes active and the content of the flag becomes static.

As I said, I do not consider this a bug. I know that, on the OpenGL side, an extra call to glGenerateMipmap is required.

My first clumsy approach to inject this glGenerateMipmap call was to attach a callback to the flag-drawable:

struct CreateMipmapCallback : osg::Drawable::DrawCallback
{
void drawImplementation( osg::RenderInfo& renderInfo, const osg::Drawable* dwbl ) const override
  {
    // these three clears I made to be able to spot
    // them in a trace of the GL calls
    glClear( GL_DEPTH_BUFFER_BIT );
    glClear( GL_DEPTH_BUFFER_BIT );
    glClear( GL_DEPTH_BUFFER_BIT );

    // this crashes
    // glGenerateMipmap(GL_TEXTURE_2D);

    // just decorate the existing draw function.
    dwbl->drawImplementation(renderInfo);
  }
};

But glGenerateMipmap segfaults. To be able to call it, I included and linked GLEW. Could that be the problem? I somehow have the impression that I am following an invalid function pointer here.

I have attached the modified osgprerender source code. GLEW must be linked to it. I build with this cmdline

g++ osgprerender.cpp -o osgprerender `pkg-config --libs --cflags openscenegraph` -std=c++11 -lGLEW -lGL

I have tested this with OSG 3.4.0 on Linux 14.04 with an nvidia driver. glxinfo | grep OpenGL shows this:

OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce GTX 750 Ti/PCIe/SSE2
OpenGL core profile version string: 4.3.0 NVIDIA 384.111
OpenGL core profile shading language version string: 4.30 NVIDIA via Cg compiler
OpenGL core profile context flags: (none)
OpenGL core profile profile mask: core profile
OpenGL core profile extensions:
OpenGL version string: 4.5.0 NVIDIA 384.111
OpenGL shading language version string: 4.50 NVIDIA
OpenGL context flags: (none)
OpenGL profile mask: (none)
OpenGL extensions:

This is a "vanilla" build of OpenSceneGraph with no special build settings.

My actual target system is more complicated, since for various compatability reasons (Intel driver without proper compatability profile) I had to both build a GL3 version of OSG, and use a recent repository version of it. This might be the reason for the second problem I have, but we can discuss this later.

How do I properly call glGenerateMipmap?

Thanks!
Julius



On 04/10/2018 10:06 PM, Robert Osfield wrote:
Hi Julius,

There isn't much we can do to help at this stage as you don't provide
any information about the hadware, OS, driver, OSG version, all we
know is that you are using a render to texture technique and there is
some issue with mipmapping and some unspecified hardware, OS and OSG
version.  We don't have your sofftware, data or hardware configuration
to test against.

It could be a driver bug, it could be a scene graph set up issue, it
could be a data problem, it could be an OSG  bug, at this stage that's
all anyone could say with the information provided.

The most productive way for others to help would be if you could
provide a small test program that illustrates the problem so that
others can run this test on their own systems to see if problem
appears, this then should shine more light on the nature of the
problem and give us a better chance of getting a solution.  Sometimes
issues like this turn out to hardware/driver/OS specific so wider
testing can show this.  If it's a OSG bug then we can then use this a
unit test for testing any fixes that will be made.

Failing a means to tests things ourselves, the only workaround I an
suggest is to not using mipmapping on the texture you are rendering
to.

Robert.



On 10 April 2018 at 20:45, Julius Ziegler <zieg...@atlatec.de> wrote:
Dear OSG-friends,

I currently have a scene graph set up where a pre-render camera renders
content to a texture via an FBO, and the main camera uses this texture to
texture a quad with it. This works, in principle.

However I need mipmapping for that texture, and all but the 0th mipmap level
of the texture are empty.

With an apitracer, I found out that the glGenerateMipMap call happens

1. only in the first frame (but I want it to be called every frame).
2. before any draw calls towards the FBO (but I want it after the draw
calls).

I tried to inject a glGenerateMipMap via a DrawCallback which I attached to
the quad, and which just extends the original draw implementation
(glGenerateMipMap immediately before the original draw implementation).

With the apitracer, I validated that, at the position where I injected the
glGenerateMipMap

a. the correct texture is bound
b. the frame buffer is un-bound.

But glGenerateMipMap just seg'faults. Because of the seg'fault (I mean we
are all used to GL_ERRORS, but seg'faults?) I suspected a driver issue, but
I tried it on an alternative platform (one is Intel Graphics, one is Nvidia,
both on Linux). Both to the same result.

Can you please help? Maybe I overlooked a simple osg-ish way to achieve this
(maybe I just have to set something dirty()?)

Thanks!

Julius
_______________________________________________
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


--
Dr.-Ing. Julius Ziegler

Phone:  +49 151 722 026 63
E-Mail: zieg...@atlatec.de
Web:    www.atlatec.de

Atlatec GmbH
Haid- und Neu-Strasse 7
D-76131 Karlsruhe

Sitz der Gesellschaft: Karlsruhe | Registergericht Mannheim
Handelsregisternummer: HRB 718673 | USt-IdNr. DE293003755
Geschäftsführer: Dr. Henning Lategahn
/* OpenSceneGraph example, osgprerender.
*
*  Permission is hereby granted, free of charge, to any person obtaining a copy
*  of this software and associated documentation files (the "Software"), to deal
*  in the Software without restriction, including without limitation the rights
*  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
*  copies of the Software, and to permit persons to whom the Software is
*  furnished to do so, subject to the following conditions:
*
*  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
*  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
*  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
*  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
*  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
*  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
*  THE SOFTWARE.
*/

#include <GL/glew.h>

#include <osg/GLExtensions>
#include <osg/Node>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/MatrixTransform>
#include <osg/Texture2D>
#include <osg/TextureRectangle>
#include <osg/Stencil>
#include <osg/ColorMask>
#include <osg/Depth>
#include <osg/Billboard>
#include <osg/Material>
#include <osg/AnimationPath>

#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>

#include <osgUtil/SmoothingVisitor>

#include <osgDB/Registry>
#include <osgDB/ReadFile>
#include <osgDB/WriteFile>

#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>

#include <iostream>


// call back which creates a deformation field to oscillate the model.
class MyGeometryCallback :
    public osg::Drawable::UpdateCallback,
    public osg::Drawable::AttributeFunctor
{
    public:

        MyGeometryCallback(const osg::Vec3& o,
                           const osg::Vec3& x,const osg::Vec3& y,const osg::Vec3& z,
                           double period,double xphase,double amplitude):
            _firstCall(true),
            _startTime(0.0),
            _time(0.0),
            _period(period),
            _xphase(xphase),
            _amplitude(amplitude),
            _origin(o),
            _xAxis(x),
            _yAxis(y),
            _zAxis(z) {}

        virtual void update(osg::NodeVisitor* nv,osg::Drawable* drawable)
        {
            // OpenThreads::Thread::microSleep( 1000 );

            const osg::FrameStamp* fs = nv->getFrameStamp();
            double simulationTime = fs->getSimulationTime();
            if (_firstCall)
            {
                _firstCall = false;
                _startTime = simulationTime;
            }

            _time = simulationTime-_startTime;

            drawable->accept(*this);
            drawable->dirtyBound();

            osg::Geometry* geometry = dynamic_cast<osg::Geometry*>(drawable);
            if (geometry)
            {
                osgUtil::SmoothingVisitor::smooth(*geometry);
            }

        }

        virtual void apply(osg::Drawable::AttributeType type,unsigned int count,osg::Vec3* begin)
        {
            if (type == osg::Drawable::VERTICES)
            {
                const float TwoPI=2.0f*osg::PI;
                const float phase = -_time/_period;

                osg::Vec3* end = begin+count;
                for (osg::Vec3* itr=begin;itr<end;++itr)
                {
                    osg::Vec3 dv(*itr-_origin);
                    osg::Vec3 local(dv*_xAxis,dv*_yAxis,dv*_zAxis);

                    local.z() = local.x()*_amplitude*
                                sinf(TwoPI*(phase+local.x()*_xphase));

                    (*itr) = _origin +
                             _xAxis*local.x()+
                             _yAxis*local.y()+
                             _zAxis*local.z();
                }
            }
        }

        bool    _firstCall;

        double  _startTime;
        double  _time;

        double  _period;
        double  _xphase;
        float   _amplitude;

        osg::Vec3   _origin;
        osg::Vec3   _xAxis;
        osg::Vec3   _yAxis;
        osg::Vec3   _zAxis;

};

struct MyCameraPostDrawCallback : public osg::Camera::DrawCallback
{
    MyCameraPostDrawCallback(osg::Image* image):
        _image(image)
    {
    }

    virtual void operator () (const osg::Camera& /*camera*/) const
    {
        if (_image && _image->getPixelFormat()==GL_RGBA && _image->getDataType()==GL_UNSIGNED_BYTE)
        {
            // we'll pick out the center 1/2 of the whole image,
            int column_start = _image->s()/4;
            int column_end = 3*column_start;

            int row_start = _image->t()/4;
            int row_end = 3*row_start;


            // and then invert these pixels
            for(int r=row_start; r<row_end; ++r)
            {
                unsigned char* data = _image->data(column_start, r);
                for(int c=column_start; c<column_end; ++c)
                {
                    (*data) = 255-(*data); ++data;
                    (*data) = 255-(*data); ++data;
                    (*data) = 255-(*data); ++data;
                    (*data) = 255; ++data;
                }
            }


            // dirty the image (increments the modified count) so that any textures
            // using the image can be informed that they need to update.
            _image->dirty();
        }
        else if (_image && _image->getPixelFormat()==GL_RGBA && _image->getDataType()==GL_FLOAT)
        {
            // we'll pick out the center 1/2 of the whole image,
            int column_start = _image->s()/4;
            int column_end = 3*column_start;

            int row_start = _image->t()/4;
            int row_end = 3*row_start;

            // and then invert these pixels
            for(int r=row_start; r<row_end; ++r)
            {
                float* data = (float*)_image->data(column_start, r);
                for(int c=column_start; c<column_end; ++c)
                {
                    (*data) = 1.0f-(*data); ++data;
                    (*data) = 1.0f-(*data); ++data;
                    (*data) = 1.0f-(*data); ++data;
                    (*data) = 1.0f; ++data;
                }
            }

            // dirty the image (increments the modified count) so that any textures
            // using the image can be informed that they need to update.
            _image->dirty();
        }

    }

    osg::Image* _image;
};


struct CreateMipmapCallback : osg::Drawable::DrawCallback
{
  void drawImplementation( osg::RenderInfo& renderInfo, const osg::Drawable* dwbl ) const override
  {
    
    

    // these three clears I made to be able to spot
    // them in a trace of the GL calls
    glClear( GL_DEPTH_BUFFER_BIT );
    glClear( GL_DEPTH_BUFFER_BIT );
    glClear( GL_DEPTH_BUFFER_BIT );

    // this crashes
    // glGenerateMipmap(GL_TEXTURE_2D);

    // just decorate the existing draw function.
    dwbl->drawImplementation(renderInfo);
  }
};


osg::Node* createPreRenderSubGraph(osg::Node* subgraph,
                                   unsigned tex_width, unsigned tex_height,
                                   osg::Camera::RenderTargetImplementation renderImplementation,
                                   bool useImage, bool useTextureRectangle, bool useHDR,
                                   unsigned int samples, unsigned int colorSamples)
{
    if (!subgraph) return 0;

    // create a group to contain the flag and the pre rendering camera.
    osg::Group* parent = new osg::Group;

    // texture to render to and to use for rendering of flag.
    osg::Texture* texture = 0;
    if (useTextureRectangle)
    {
        osg::TextureRectangle* textureRect = new osg::TextureRectangle;
        textureRect->setTextureSize(tex_width, tex_height);
        textureRect->setInternalFormat(GL_RGBA);
        textureRect->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
        textureRect->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);

        texture = textureRect;
    }
    else
    {
        osg::Texture2D* texture2D = new osg::Texture2D;
        texture2D->setTextureSize(tex_width, tex_height);
        texture2D->setInternalFormat(GL_RGBA);
        texture2D->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR_MIPMAP_NEAREST );
        texture2D->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);

        texture = texture2D;
    }

    if (useHDR)
    {
        texture->setInternalFormat(GL_RGBA16F_ARB);
        texture->setSourceFormat(GL_RGBA);
        texture->setSourceType(GL_FLOAT);
    }

    // first create the geometry of the flag of which to view.
    {
        // create the to visualize.
        osg::Geometry* polyGeom = new osg::Geometry();

        polyGeom->setName( "PolyGeom" );

        polyGeom->setDataVariance( osg::Object::DYNAMIC );
        polyGeom->setSupportsDisplayList(false);

        osg::Vec3 origin(0.0f,0.0f,0.0f);
        osg::Vec3 xAxis(1.0f,0.0f,0.0f);
        osg::Vec3 yAxis(0.0f,0.0f,1.0f);
        osg::Vec3 zAxis(0.0f,-1.0f,0.0f);
        float height = 100.0f;
        float width = 200.0f;
        int noSteps = 20;

        osg::Vec3Array* vertices = new osg::Vec3Array;
        osg::Vec3 bottom = origin;
        osg::Vec3 top = origin; top.z()+= height;
        osg::Vec3 dv = xAxis*(width/((float)(noSteps-1)));

        osg::Vec2Array* texcoords = new osg::Vec2Array;

        // note, when we use TextureRectangle we have to scale the tex coords up to compensate.
        osg::Vec2 bottom_texcoord(0.0f,0.0f);
        osg::Vec2 top_texcoord(0.0f, useTextureRectangle ? tex_height : 1.0f);
        osg::Vec2 dv_texcoord((useTextureRectangle ? tex_width : 1.0f)/(float)(noSteps-1),0.0f);

        for(int i=0;i<noSteps;++i)
        {
            vertices->push_back(top);
            vertices->push_back(bottom);
            top+=dv;
            bottom+=dv;

            texcoords->push_back(top_texcoord);
            texcoords->push_back(bottom_texcoord);
            top_texcoord+=dv_texcoord;
            bottom_texcoord+=dv_texcoord;
        }


        // pass the created vertex array to the points geometry object.
        polyGeom->setVertexArray(vertices);

        polyGeom->setTexCoordArray(0,texcoords);

        osg::Vec4Array* colors = new osg::Vec4Array;
        colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
        polyGeom->setColorArray(colors, osg::Array::BIND_OVERALL);

        polyGeom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUAD_STRIP,0,vertices->size()));

        // new we need to add the texture to the Drawable, we do so by creating a
        // StateSet to contain the Texture StateAttribute.
        osg::StateSet* stateset = new osg::StateSet;

        stateset->setTextureAttributeAndModes(0, texture,osg::StateAttribute::ON);

        polyGeom->setStateSet(stateset);

        polyGeom->setUpdateCallback(new MyGeometryCallback(origin,xAxis,yAxis,zAxis,1.0,1.0/width,0.2f));

        osg::Geode* geode = new osg::Geode();
        geode->addDrawable(polyGeom);

        parent->addChild(geode);
        osg::ref_ptr<CreateMipmapCallback> cb = new CreateMipmapCallback();        
        polyGeom->setDrawCallback( cb );
    }


    // then create the camera node to do the render to texture
    {
        osg::Camera* camera = new osg::Camera;

        // set up the background color and clear mask.
        camera->setClearColor(osg::Vec4(0.1f,0.1f,0.3f,1.0f));
        camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

        const osg::BoundingSphere& bs = subgraph->getBound();
        if (!bs.valid())
        {
            return subgraph;
        }

        float znear = 1.0f*bs.radius();
        float zfar  = 3.0f*bs.radius();

        // 2:1 aspect ratio as per flag geometry below.
        float proj_top   = 0.25f*znear;
        float proj_right = 0.5f*znear;

        znear *= 0.9f;
        zfar *= 1.1f;

        // set up projection.
        camera->setProjectionMatrixAsFrustum(-proj_right,proj_right,-proj_top,proj_top,znear,zfar);

        // set view
        camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
        camera->setViewMatrixAsLookAt(bs.center()-osg::Vec3(0.0f,2.0f,0.0f)*bs.radius(),bs.center(),osg::Vec3(0.0f,0.0f,1.0f));

        // set viewport
        camera->setViewport(0,0,tex_width,tex_height);

        // set the camera to render before the main camera.
        camera->setRenderOrder(osg::Camera::PRE_RENDER);

        // tell the camera to use OpenGL frame buffer object where supported.
        camera->setRenderTargetImplementation(renderImplementation);


        if (useImage)
        {
            osg::Image* image = new osg::Image;
            //image->allocateImage(tex_width, tex_height, 1, GL_RGBA, GL_UNSIGNED_BYTE);
            image->allocateImage(tex_width, tex_height, 1, GL_RGBA, GL_FLOAT);

            // attach the image so its copied on each frame.
            camera->attach(osg::Camera::COLOR_BUFFER, image,
                           samples, colorSamples);

            camera->setPostDrawCallback(new MyCameraPostDrawCallback(image));

            // Rather than attach the texture directly to illustrate the texture's ability to
            // detect an image update and to subload the image onto the texture.  You needn't
            // do this when using an Image for copying to, as a separate camera->attach(..)
            // would suffice as well, but we'll do it the long way round here just for demonstration
            // purposes (long way round meaning we'll need to copy image to main memory, then
            // copy it back to the graphics card to the texture in one frame).
            // The long way round allows us to manually modify the copied image via the callback
            // and then let this modified image by reloaded back.
            texture->setImage(0, image);
        }
        else
        {
            // attach the texture and use it as the color buffer.
            camera->attach(osg::Camera::COLOR_BUFFER, texture,
                           0, 0, false,
                           samples, colorSamples);
        }


        // add subgraph to render
        camera->addChild(subgraph);

        parent->addChild(camera);

    }

    return parent;
}

int main( int argc, char **argv )
{
    // use an ArgumentParser object to manage the program arguments.
    osg::ArgumentParser arguments(&argc,argv);

    // set up the usage document, in case we need to print out how to use this program.
    arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is the example which demonstrates pre rendering of scene to a texture, and then apply this texture to geometry.");
    arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");
    arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information");
    arguments.getApplicationUsage()->addCommandLineOption("--fbo","Use Frame Buffer Object for render to texture, where supported.");
    arguments.getApplicationUsage()->addCommandLineOption("--fb","Use FrameBuffer for render to texture.");
    arguments.getApplicationUsage()->addCommandLineOption("--pbuffer","Use Pixel Buffer for render to texture, where supported.");
    arguments.getApplicationUsage()->addCommandLineOption("--window","Use a separate Window for render to texture.");
    arguments.getApplicationUsage()->addCommandLineOption("--width","Set the width of the render to texture.");
    arguments.getApplicationUsage()->addCommandLineOption("--height","Set the height of the render to texture.");
    arguments.getApplicationUsage()->addCommandLineOption("--image","Render to an image, then apply a post draw callback to it, and use this image to update a texture.");
    arguments.getApplicationUsage()->addCommandLineOption("--texture-rectangle","Use osg::TextureRectangle for doing the render to texture to.");

    // construct the viewer.
    osgViewer::Viewer viewer(arguments);

    // add stats
    viewer.addEventHandler( new osgViewer::StatsHandler() );

    // add the record camera path handler
    viewer.addEventHandler(new osgViewer::RecordCameraPathHandler);

    // add the threading handler
    viewer.addEventHandler( new osgViewer::ThreadingHandler() );

    // if user request help write it out to cout.
    if (arguments.read("-h") || arguments.read("--help"))
    {
        arguments.getApplicationUsage()->write(std::cout);
        return 1;
    }

    unsigned int tex_width = 1024;
    unsigned int tex_height = 512;
    unsigned int samples = 0;
    unsigned int colorSamples = 0;

    while (arguments.read("--width", tex_width)) {}
    while (arguments.read("--height", tex_height)) {}

    osg::Camera::RenderTargetImplementation renderImplementation = osg::Camera::FRAME_BUFFER_OBJECT;

    while (arguments.read("--fbo")) { renderImplementation = osg::Camera::FRAME_BUFFER_OBJECT; }
    while (arguments.read("--pbuffer")) { renderImplementation = osg::Camera::PIXEL_BUFFER; }
    while (arguments.read("--pbuffer-rtt")) { renderImplementation = osg::Camera::PIXEL_BUFFER_RTT; }
    while (arguments.read("--fb")) { renderImplementation = osg::Camera::FRAME_BUFFER; }
    while (arguments.read("--window")) { renderImplementation = osg::Camera::SEPARATE_WINDOW; }
    while (arguments.read("--fbo-samples", samples)) {}
    while (arguments.read("--color-samples", colorSamples)) {}

    bool useImage = false;
    while (arguments.read("--image")) { useImage = true; }

    bool useTextureRectangle = false;
    while (arguments.read("--texture-rectangle")) { useTextureRectangle = true; }

    bool useHDR = false;
    while (arguments.read("--hdr")) { useHDR = true; }


    // load the nodes from the commandline arguments.
    osg::Node* loadedModel = osgDB::readNodeFiles(arguments);

    // if not loaded assume no arguments passed in, try use default mode instead.
    if (!loadedModel) loadedModel = osgDB::readNodeFile("cessna.osgt");

    if (!loadedModel)
    {
        return 1;
    }

    // create a transform to spin the model.
    osg::MatrixTransform* loadedModelTransform = new osg::MatrixTransform;
    loadedModelTransform->addChild(loadedModel);

    osg::NodeCallback* nc = new osg::AnimationPathCallback(loadedModelTransform->getBound().center(),osg::Vec3(0.0f,0.0f,1.0f),osg::inDegrees(45.0f));
    loadedModelTransform->setUpdateCallback(nc);

    osg::Group* rootNode = new osg::Group();
    rootNode->addChild(createPreRenderSubGraph(loadedModelTransform,tex_width,tex_height, renderImplementation, useImage, useTextureRectangle, useHDR, samples, colorSamples));

    //osgDB::writeNodeFile(*rootNode, "test.osgb");

    // add model to the viewer.
    viewer.setSceneData( rootNode );

    return viewer.run();
}
_______________________________________________
osg-users mailing list
osg-users@lists.openscenegraph.org
http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org

Reply via email to