[petsc-users] Paraview 3.x

[Håkon Strandenes]

On 17. april 2015 05:57, Sanjay Kharche wrote:
>
> Hi
>
> My grid is rectilinear with equal spacing in all directions, it is a regular structured grid.

It doesn't matter if your dataset physically/numerically has constant 
spacing, because as long as your dataset is loaded as a .vts file, it is 
seen only as a structured grid by Paraview, but it does not see 
properties like orthogonality and uniform spacing. Your *.vts file can 
in general contain data on any structured mesh, even curved ones, and 
Paraview will treat it that way as well.

> As of now, I am working through the various versions of paraview on my Fedora/Linux as well as a apple mac (debian) to find a working balance version of paraview for my purpose. It seems this discussion may be more for another list than this one. I will still elaborate.
>
> When I load the 3D vts structured grid (output from my 3D petsc based program) into paraview 3.4, I do not get an option to render volume. There are no error messages.

That's true. No error message. Paraview, at least previously, could not, 
by design, do volume rendering of anything else than unstructured grids 
and "image data" (rectilinear grids with constant spacing), so the 
option are hidden. But no error has occurred, so no error message.

 > The best I can do is get an isosurface or threshold the data.

Then Paraview has successfully loaded your data. No errors.

> When I used paraview 4.3.1 distro binary, I can viz it but the controls are different. I spend some time getting familiar with the controls yesterday. My pvbatch scripts are going to be remade if I am to go down the 4.3.1 route.

At some point you will have to do that anyway.

> Another fix I implemented is that to do a binary output, and then post-process so that my current set up of paraview/vtk still works.

I guess that when you load your binary dataset, Paraview suddenly sees 
this as a "image data" dataset, which you can use for volume rendering.

For info on the VTK file formats, see 
http://ins.uni-bonn.de/teaching/alumni/bebendorf/Praktikum_SS12/vtk_file_formats.pdf

Anyways, I absolutely support Jed Brown's advice: upgrade. Asap. 
Especially if that solves your problem.

(However, I cannot get volume rendering working with PV 4.3.1 on 
non-equidistant meshes myself, but again, if upgrading helps for you, do 
it!)

Regards,
Håkon



>
> cheers
> Sanjay
>
>
> ________________________________________
> From: Jed Brown [jed at jedbrown.org]
> Sent: 16 April 2015 20:25
> To: Sanjay Kharche; petsc-users at mcs.anl.gov
> Subject: Re: [petsc-users] Paraview 3.x
>
> Sanjay Kharche <Sanjay.Kharche at manchester.ac.uk> writes:
>
>> Hi
>>
>> I have 3D output in vts format produced using PetscViewerVTKopen and
>> VecView. I cannot volume render the data using paraview 3.x.
>
> Can't open it at all or can't volume render it?  Do you get an error message?
>
>> The latest version of paraview (4.2.x) can visualise it.
>
> Why not use current Paraview?
>
>> How can I make 3D vts output that is compatible with paraview 3.x?
>