Is it possible that vtk implements pagelod, similar to osg

osg pagelod example
PagedLOD - FlightGear wiki

Here is a simple example of creating a osg::PagedLOD node with two children nodes, one is a local geometry and the other is an external model file.
This code creates a PagedLOD node that displays a box when the eye point is within 1000 units from the node, and displays a cow model when the eye point is beyond 1000 units from the node. The cow model is loaded from the file “cow. osg” in the current directory.

// create a PagedLOD node
osg::ref_ptr<osg::PagedLOD> plod = new osg::PagedLOD();
plod->setName("plod for example");

// set the range mode to distance from eye point

// create a local geometry as the first child node
osg::ref_ptr<osg::Geode> geode = new osg::Geode();
geode->addDrawable(new osg::ShapeDrawable(new osg::Box(osg::Vec3(0.0f,0.0f,0.0f),10.0f)));

// set the range of the first child node to [0, 1000]
plod->setRange(0, 0.0f, 1000.0f);

// set the file name of the second child node to "cow.osg"
plod->setFileName(1, "cow.osg");

// set the range of the second child node to [1000, FLT_MAX]
plod->setRange(1, 1000.0f, FLT_MAX);

// set the database path to the current directory


So, what are you getting?