HI Catalin, OpenGL clip planes are positional state which requires them to be applied with the current modelview matrix to position them in in eye coordinates where the clipping is done on the GPU. This positioning means that each individual OpenGL clip plan can only be in one place at one time, which in turn means that when the OSG applies the clipplane only the last one applied will be the one that is effective.
Robert. On Wed, 23 Oct 2019 at 11:48, Catalin <inbox....@gmail.com> wrote: > Hi, > > I have an issue with clipping planes, if you set 2 different clipping > planes to 2 different objects, only the last clipping plane is used. I was > expecting each object to be drawn with its clipping plane. > > osg::ref_ptr<osg::ClipNode> clipNode1 = new osg::ClipNode; > clipNode1->addClipPlane(new osg::ClipPlane(0)); > clipNode1->getClipPlane(0)->setClipPlane(1.0, 0.0, 0.0, -2000.0); > > osg::ref_ptr<osg::ClipNode> clipNode2 = new osg::ClipNode; > clipNode2->addClipPlane(new osg::ClipPlane(0)); > clipNode2->getClipPlane(0)->setClipPlane(-1.0, 0.0, 0.0, -2000.0); > > osg::ShapeDrawable* s1 = new osg::ShapeDrawable(new > osg::Box(osg::Vec3(2000, 0, 0), 500)); > clipNode1->addChild(s1); > osg::ShapeDrawable* s2 = new osg::ShapeDrawable(new > osg::Box(osg::Vec3(-2000, 0, 0), 500)); > clipNode2->addChild(s2); > > Every box is shown in half because of the clipping plane. > > *Case 1* > root->addChild(clipNode1); > //root->addChild(clipNode2); > > [image: image.png] > > *Case 2* > //root->addChild(clipNode1); > root->addChild(clipNode2); > > [image: image.png] > > *Case 3* > root->addChild(clipNode1); > root->addChild(clipNode2); > > [image: image.png] > > I was expecting both boxes, S1 and S2 to be drawn. > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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