Learning Forum

[YouwuApo]

HI, 

I'm using DEFINE_GRID_MOTION and I encounter a strange problem. I monitor the displacement of one node in each time step and output the result to a txt file. But the displacement results were output twice per time step. When I built and loaded the same UDF in another case, however, displacement results were output once per time step. I'm very confused about why this happens. Obviously, it's because DEFINE_GRID_MOTION was executed twice in each time step, how can I prevent this? And could  someone tell me why DGM is executed differently in two cases (all of their parameter settings are the same, only the grid is different).

 

[YouwuApo]

Hi,

After some trials, I found the problem. When I used Diffusion for smoothing, this problem shown up. Other smoothing methods like spring don't have this kind of problem. So, after I changed my smoothing method, everything is fine. But I still don't understand why the diffusion method executes DEFINE_GRID_MOTION twice.