[osg-users] Change picked points' color ---why can't work in the pick function?

[Trajce Nikolov NICK]

Hi,

can you try geom->dirtyDisplayLists() after changing the color?

Nick

On Wed, Sep 2, 2015 at 12:27 PM, Yexin W <xxtop716 at 163.com> wrote:

> Hi,
>
> Guys, I have a pick problem. What I want to do is loading 10 points with
> their loactions and colors. I want to use poly pick, and use another color
> to show the picked points.
> The loading points process is as follows:
>
>
> Code:
>
> osg::ref_ptr<osg::Geometry> geom = new osg::Geometry();
> osg::ref_ptr<osg::Vec3Array> v = new osg::Vec3Array;
> osg::ref_ptr<osg::Vec4Array> clr = new osg::Vec4Array;
> v->push_back(osg::Vec3(0.0, 0.0, 0.0));
> ... // 10 points in total
> clr->push_back(osg::Vec4(1.0, 0.0, 1.0, 1.0f));
> ...// set the color
> geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POINTS, 0,
> v->size()));
> // after set the color and normal, add the geometry to Geode node
> geode->addDrawable(geom.get());
>
>
>
>
>
> Then I want to use ploy pick, the problem is : when I put the following
> codes in the pick() function in Pickhandler class, I found out that the
> color of the picked premitiveset has been changed, however, nothing changed
> in the view window. The following codes are in pick function:
>
>
> Code:
>
> if (picker->containsIntersections())
> {
> osgUtil::PolytopeIntersector::Intersections intersections =
> picker->getIntersections();
> osgUtil::PolytopeIntersector::Intersections::iterator iter;
> for (iter = intersections.begin(); iter != intersections.end(); iter++)
> {
> osg::NodePath nodepath = (*iter).nodePath;
> node = (nodepath.size() >= 1) ? nodepath[nodepath.size() - 1] : 0;
> int pointIndex = (*iter).primitiveIndex;
> osg::Geode * geode = dynamic_cast<osg::Geode*> (node);
> osg::Geometry * geom = dynamic_cast<osg::Geometry*>(geode->getDrawable(0));
> osg::Vec4Array * clrary =
> dynamic_cast<osg::Vec4Array*>(geom->getColorArray());
> clrary->operator [] (pointIndex) = osg::Vec4(0.0, 1.0, 0.0, 1.0f);
> geom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
> node->addUpdateCallback(new CessnaCallback()); // not helpful
> viewer->updateTraversal(); //not helpful
> //viewer->run();//not helpful
> }
> }
>
>
>
>
>
> First, I thought may be the colors have not been changed, so I tested
> changing several points' color in the main function, like this:
>
>
> Code:
>
> osg::Geode * geode1 = dynamic_cast<osg::Geode*> (nodePt.get());
> osg::Geometry * geom =
> dynamic_cast<osg::Geometry*>(geode1->getDrawable(0));
> osg::Vec4Array * clrary =
> dynamic_cast<osg::Vec4Array*>(geom->getColorArray());
> clrary->operator [] (10) = osg::Vec4(0.0, 1.0, 0.0, 1.0f);
> clrary->operator [] (6) = osg::Vec4(0.0, 1.0, 0.0, 1.0f);
> clrary->operator [] (2) = osg::Vec4(0.0, 1.0, 0.0, 1.0f);
> geom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
>
>
>
>
> It changed the colors! So it confuses me why it can't work in the pick
> function? Any body any idears?
> Any ideas and suggestions would be appreciated!
>
>
> Thank you!
>
> Cheers,
> Yexin
>
> ------------------
> Read this topic online here:
> http://forum.openscenegraph.org/viewtopic.php?p=64994#64994
>
>
>
>
>
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>



-- 
trajce nikolov nick
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