general framework to compare different .vtk files (just visualizing)

Dear all,

I am a beginner to paraview and just confronted with a rather simple issue.
I have two different .vtk files (groups) where each group stores a different number of time steps and I would like to compare them in two render views.
Here is a snippet of my pipeline with the two groups (they have the same name, but they actually store different things):

So in the left renderview, the upper group is active and in the right view the bottom group respectively; With “active” I mean that the eye toggle is shown in black.
However it seems that both views are still coupled somehow, because, when I scroll though the time steps, the new time step values are applied to both views and not only to one of them what I would like to achieve.

Any input is greatly appreciated!

Yes, when you are stepping through time in ParaView, that is a global parameter that applies to all views. As long as the data you loaded all has consistent time, this makes it much easier and less error prone to explore time.

If you want to see a different time on different data sets, the easiest way to do that is to apply the Force Time filter. This filter will ignore the time set and show data at the time value set in the filter.

Since your vtk file groups have different numbers of time steps, it sounds like they are at different time scales. Another option you might want to explore is to adjust them to be at the same time scale so that when you “play” time they remain consistent. Assuming that each data set writes time at regular intervals, you should be able to use the Temporal Shift Scale filter to adjust the time values (initially just set to the time indices) to be consistent.

The Force Time filter actually helps me, glad to be aware of this feature now!
But my problem was actually a different one: When I stapped through time, both views showed me the content of the very same file. I guess this behaviour is caused by storing both files in the same folder under the same name (I open the file first in paraview, restart my computation and overwrite the file and finally open it again in paraview). Storing the results in a seperate folder resolved my issue.

So does through time internally do some reloading operation on the underlying files? This would explain what I observed.

Thanks again!

I guess I still don’t understand your question. I assumed you were loading two different (groups of) files with different names. They looked the same in that tiny piece of screenshot, but I assumed that the end part of the filenames were different (e.g. solution_small_*.vtk and solution_big_*.vtk). Are they the same thing? If you load the same file (or file series) twice, then, yeah, ParaView will load the same data twice. And, yeah, when you ask for a different time step, ParaView will load data for the new time step. I don’t know what else you would want or expect to happen.

I will try to make it more clear what I did:
I load one group of files in paraview (File->open…). Then, I restart my computation which writes the results in the very same group that is already open in paraview. After that, I go again to paraview (File->open…) and open the overwritten file. At the end, I have two group of files open with the very same names. One stores the old content and the other the overwritten content; At least I assume this is how it works.

I guess my question is more like:
If I open a file, does paraview copy the file contents and store it internally somehow or does paraview access the content from the place in memory where the file is actually stored? If the latter is true, then of course I see both times the same content.

Don’t do that. I don’t want to dive into technical details of when ParaView does and doesn’t refresh data from files, but suffice it to say that ParaView sometimes pulls new data from files, and there are use cases where refreshing data is desired.

Run your simulation to create solution files in two different places or copy the first solution files before opening them in ParaView.