View disappears and creates artifacts in multiblock pan and rotate

Dear all
I have created a multiblock datafile with two DTM (digital terrain model).
If I pan or rotate the view, it disappears and creates artifacts.
This doesn’t happen in the case I have a single DTM file.

this is the multiblock datafile
mblc.vtm (241 Bytes)

please share the associated dtm0.vtp and vtm1.vtp

https://1drv.ms/u/s!AgtqczEzv0qMlJlSqPwN65YZkpbS4g?e=ZDnRmf

https://1drv.ms/u/s!AgtqczEzv0qMlJlTahjfPQAdhn0lXQ?e=xlqC9J

Your dataset contains NaN points (id 0 to 484) , which completely breaks the Level Of Details filters which is automatically applied when moving the view around.

You can just disable LOD by setting Edit -> Settings -> RenderView -> LOD Treshold to a great value.

However, NaN points are not supported in ParaView, and you will likely have many more issues if you do not remove these points, even occasional crashes.

Hi Mathieu
Thank’s for your prompt reply.
Unfortunately, in digital terrain models NaN values are very frequent. A possibility is to set Nan value to zero or another value.I am evaluating this solution in my application.

In any case, I’m searching how change LOD Setting, programmatically, since I start the visualization in bash mode (pvpython) and then rotate and pan with the Interact() method inserted in the pvpython script.
Have you any suggestion or links?

NaN values are fine in data arrays, but not in point coordinates.
Where do you render a NaN points ?

But cleaning them up in a ProgrammableFilter should be very easy.
We could even add this functionality to the Clean filter.

In any case, I’m searching how change LOD Setting, programmatically, since I start the visualization in bash mode (pvpython) and then rotate and pan with the Interact() method inserted in the pvpython script.

settings = servermanager.ProxyManager().GetProxy("settings", "RenderViewSettings")
settings.LODThreshold = 100000

As you know, a DTM is a series of X,Y,Z value, where Z value is the elevation of the terrain @ x,y location.
I use an .asc file.
As example, yiou can wiew NAN values at the end of this file:
https://1drv.ms/u/s!AgtqczEzv0qMlJlVD5ZxMQRRS4JPZQ?e=6PawUO

When I render a DTM in paraview, I must define:

“PointData Scalars” (in my vtp file = ‘Elevation’, eg the Z value)
“Points” (in my vtp file = ‘Points’ eg the X,Y,Z coordinates)
“Polys” (in my vtp file = ‘Connectivity’ eg sequence index of linkings points)

The grid mesh must join all the points, which coordinates are defined in “Points”. So, I have to insert the X,Y,Z triple for each points. If in some points there is no elevation (i.e. there is a NAN value), how can I define the Z coordinates of these “Points” in the mesh without using NAN value?

You should either remove these points and the cells associated with it, or use 0 instead of NaN.

Ok, Thanks