Reduce the size of grid data


Is there a filter or process that can reduce the size of a rectilinear grid. i.e, I want to reduce the mesh from 100x100x100 to 50x50x50 but have the overall outer dimensions the same, so that the blocks are averaged onto the new array?




By doing this, you made a new grid. If you want to show how dense your mesh is, just to show the boundary layer’s mesh is okay.

We have essentially created too much data, and want to reduce the size of the mesh down to a quarter, with the same outer dimensions. essentially condensing 8 cell blocks to 1, and in doing so smooth out some of the data. We could just write a script that did this averaging the data and taking into account any covariance, I was just hoping that a filter already existed to do this. Trying to avoid doing hundreds of data runs again at a lower grid size.

so, what is your rule to write mesh?

The Extract Subset filter let’s you change the i/j/k sampling directions. Change the Sample Rate I/J/K as needed. Note, these are advanced properties and you’ll have hit on the “gear” icon to see them.

Does it only work for vtk?

I’ve tested using *.foam, not working (you cannot use extract subset filter).

I do not how and what is the mesh of the author.

The original email clearly states “…reduce the size of a rectilinear grid”. Rectilinear grid is a specific type of data type called vtkRectilinearGrid. Extract Subset filter only applies to dataset types that are structured like rectilinear grid, image data, structured grid etc.

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Thanks for sharing. I’ve learnt that. Sorry about it.


Can this filter achieve this?

We could just write a script that did this averaging the data and taking into account any covariance

From what I understand, extract subset pick up points every some points.

Can it achieve:

averaging the data


If you are using OpenFOAM

maybe convert to vtk is a better solution.