How to convert DEM point data to cell data form?

Hello everyone!

I have a DEM case that contains two solid particles and I would like to have the results in cell data form (e.g., void fraction, velocity, …etc) instead of the default DEM output (point data “Diameter, Velocity”).

I tried using ParaView filter “point to cell data”, but it didn’t work. Maybe, I did something no correct, because I am not expert in the Paraview.

I appreciate it if somebody can give me good directions!


Hi Mohammed. Are you referring to VTK outputs? When you define a VTK output region, you can select it as either Cell or Region data. You will be presented with different choices depending on how the output region was defined. Once a region has been defined, you can’t change it’s type, but you can add new output regions (+).

Please let me know if you have further questions.

I meet the same problem , Have you solved it yet

Dear Charles;

Thank you for your reply!
I chose “Cell data”, but the “Select data to write” list is only active for the fluid phase (see below!)


Yes, I solved it, but not in MFiX setup. I did post-processing using a user-defined R-code for conversion of the particle data to cell data which I want.


if possible Can you explain the detailed procedures or send your UDF

I sliced the particle domain (xmin:xmax, ymin:ymax) e.g., 10 vertical slices
in each slice box, I counted all the particles which are located inside it. If you got the number of particles in each vertical slice, then you can calculate the particle void fraction from this equation:
EP_s1(j) = N_p_s1(i)Vol_p_s1/Vol_c(j)
EP_s1(j): particle void fraction of solid phase “s1” in the slice of index j,
N_p_s1: number of particles of solid phase “s1” in the slice of index j,
Vol_p_s1: volume of individual particle of solid phase “s1”= pi/6
Vol_c: volume of slice of index j = (xmax-xmin)(y(j+1)-y(j))(zmax-zmin)