[vtkusers] How to fix incorrect rendering

[Alex Malyushytskyy]

Hi,

I have geometrical data which represent buildings and comes from the stl file..
I have a number of  horizontal triangles ( triangulated polygons )
which  with some height increment can describe the .building layer by
layer.
Lets cool them floor. ( distance between them is smaller than between
floors, but presentation is the same.
Walls were formed by connecting points of the polygon with appropriate
points on the polygon above it.

With such structure  floor triangles under the normal conditions
should not be ever visible unless it is the top and ground level
floor.

Here is a problem.

Model is created and is displayed ok while the camera is somehow far
away from the building.
internal floor triangles are not visible.

But in case of zooming external wall triangles disappear and you can
see the internal floor triangles instead.
Camera is not behind the wall triangles,  cause you still can see the
common for floor triangles and wall triangles nodes on the boundary.

Also depending on the zoom  sometimes it is like every second or third
 layer of the wall disappear.

I tried to load such data in ParaView and it shows exactly the same problem,

I can't find any working solution.  Size of the data does not allow me
to remove "internal" floor triangles manually and
I can't think about any automatic way to do it.

I tried to turn on immediate mode rendering without success.

Any help is appreciated.

Thanks,
Alex

.