[vtkusers] I'm a vtk newbie, having a problem with vtkLODProp3D

[kplusplus at comcast.net]

I'm writing my first vtk app in C++ and am running into a problem.  I'm 
rendering a pretty large dataset on my not-very-powerful computer, so I 
need multiple levels of detail a-la ParaView, so I initially tried to 
use vtkLODActor.  I didn't like the dot field visualization, so I 
decided to go to vtkLODProp3D instead.  When I compile and run the 
program, it displays the high-detail version, which it's supposed to 
do.  When I rotate it or zoom in for the first time, it switches to the 
low-detail verison and back to high detail when I stop moving the 
dataset.  However, the next time I try to move it, the visualization 
"stutters" (actually, it can't decide between high- and low-detail for a 
couple seconds) and then permanently switches to low detail.  This, of 
course, is not good.

Here are (what I think are) the relevant lines:

renWinInteractor->SetDesiredUpdateRate(5.0);
renWinInteractor->SetStillUpdateRate(0.5);
renWinInteractor->Initialize();
.....
vtkLODProp3D *prop = vtkLODProp3D::New();
prop->AddLOD(highMapper, 5.0);
prop->AddLOD(lowMapper, 0.5);
ren->AddActor(prop);

I'm thinking I might be having a problem getting my head around the 
"time" arguments to SetDesiredUpdateRate/SetStillUpdateRate/AddLOD.  Do 
they look proper?  If so, what's causing my visualization to get all 
wonky?  If not, how do I fix 'em?

Thanks in advance,
  -- edk