[osg-users] Bug while updating geometry in Linux

[Robert Osfield]

HI Nikita,

I don't have time to try and the example problem right now, my best
guide having had a quick read through is that perhaps you need to a a
vertices->dirty() after you've done the vertices->push_back().  For a
straight GL vertex array this won't be required, but if you are using
VBO's this will be required so the OSG knows to updload the data to
the GPU.

Robert.

On 26 January 2017 at 09:27, Nikita Petrov <nikitapetroff at gmail.com> wrote:
> Hi,
>
> I am trying to port my app from Windows to Linux.
> I have a ribbon, which is updated dynamically. I add 2 points to vertices and I use GL_TRIANGLE_STRIP to create a ribbon.
> On Windows everything works fine.
> But on Linux all new vertices go to coordinates (0,0,0) after calling geometry->dirtyBound();
>
> I even created a small app to test this behaviour on Linux. It should draw sine function ribbon.
> Here's the code:
>
> osg::ref_ptr<osg::Vec3Array> vertices;
> osg::ref_ptr<osg::Geometry> geometry;
> osg::DrawArrays* drawArrays;
> int count;
>
> class UpdateVertex: public osg::NodeCallback
> {
> public:
>   UpdateVertex() {}
>   virtual void operator()(osg::Node* node, osg::NodeVisitor* nv);
> };
>
> void UpdateVertex::operator()(osg::Node* node, osg::NodeVisitor* nv)
> {
>   OpenThreads::Thread::microSleep(1000);
>
>   vertices->push_back(osg::Vec3(1+count/200.0, 1, 1+sin(count*M_PI/180.0)));
>   vertices->push_back(osg::Vec3(1+count/200.0, 2, 1+sin(count*M_PI/180.0)));
>   count++;
>
>   drawArrays->setCount(vertices->size());
>   geometry->dirtyBound();
>
>   traverse(node, nv);
> }
>
> int main(int argc, char *argv[])
> {
>     vertices = new osg::Vec3Array();
>
>     count = 120;
>     for (int i=0;i<count;i++)
>     {
>         vertices->push_back(osg::Vec3(1+i/200.0, 1, 1+sin(i*M_PI/180.0)));
>         vertices->push_back(osg::Vec3(1+i/200.0, 2, 1+sin(i*M_PI/180.0)));
>     }
>
>     osg::ref_ptr<osg::Vec3Array> normal = new osg::Vec3Array();
>     normal->push_back(osg::Vec3(0.0f, 0.0f, 1.0f));
>     osg::ref_ptr<osg::Vec4Array> color = new osg::Vec4Array();
>     color->push_back(osg::Vec4(0,0,1,0.8f));
>
>     geometry = new osg::Geometry;
>     geometry->setDataVariance(osg::Object::DYNAMIC);
>     geometry->setUseDisplayList(false);
>     geometry->setVertexArray(vertices.get());
>     geometry->setNormalArray(normal.get());
>     geometry->setNormalBinding(osg::Geometry::BIND_OVERALL);
>     geometry->setColorArray(color.get());
>     geometry->setColorBinding(osg::Geometry::BIND_OVERALL);
>
>     drawArrays = new osg::DrawArrays(GL_TRIANGLE_STRIP, 0, vertices->size());
>     geometry->addPrimitiveSet(drawArrays);
>
>     osg::ref_ptr<osg::Geode> geode = new osg::Geode();
>     geode->addDrawable(geometry.get());
>     geode->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
>
>     osg::ref_ptr<osg::Group> root = new osg::Group();
>
>     root->addChild(geode.get());
>
>     root->addUpdateCallback(new UpdateVertex);
>
>     osgViewer::Viewer viewer;
>     viewer.setSceneData(root.get());
>     viewer.getCamera()->setSmallFeatureCullingPixelSize(0);
>     viewer.getCamera()->setClearColor(osg::Vec4(1,1,1,1));
>     viewer.addEventHandler(new osgViewer::StatsHandler);
>
>     viewer.realize();
>
>     return viewer.run();
> }
>
> And you can see what I get in the attachements.
> If I press "S" to see number of vertices (thanks to StatsHandler), it is always increasing. So new vertices are added, but in (0,0,0) coordinates.
> My guess is that geometry->dirtyBound(); is not working corectly.
>
> I use master build of OSG.
> On Windows I use x86 build with Visual Studio 2013.
> On Linux Mint 18 Cinnamon 64-bit, I use x64 build with Qt Creator (GCC 64bit).
>
> Hope that somebody have a clue to that issue.
>
> Best regards,
> Nikita
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=70051#70051
>
>
>
>
> Attachments:
> http://forum.openscenegraph.org//files/2_123.png
> http://forum.openscenegraph.org//files/1_632.png
>
>
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