How to access the value of the custom properties defined in another API in the CUDA API?

David_N

I am compiling a contact force model. In the CPU API, I can successfully access the custom property calculated by another volume force model. However, after converting the contact model to the CUDA version, I can no longer access this custom property value. Could you please tell me where the problem in my code might be?

Stephen Cole

Hi,

Just to check if you run the model on CPU can you still access the property?

Custom properties are defined on CPU and when you load a model into EDEM, even if you run it on GPU, the code runs through the CPU part first to initiate the properties. So if it runs on CPU OK we can rule out any issues on the CPU side and just focus on debugging the GPU.

Looking at the code, so long as there is only 1 Custom Property, it seems to be implemented OK.

On the GPU it looks like you are defining the custom property as a customPropReal, then assigning the value as longReal to mh1 then converting to real mh1.

I'm unsure if this means we are defining mh1 twice, once as longReal once as real and if this is causing problems.

I don't know if you can use the convertToReal directly on *m1_ptr but it's worth trying that.

Or instead of real mhl = CUtilities… … change the name so its:

real mh1_converted = CUtilities…

So we're not using the same variable name twice.

Otherwise you could try debugging with printf to confirm which values are been calculated.

The best way to check this is to print out the values during run time to find the issue. To do this on CUDA GPU you can use printf and start EDEM with --no-free flag.

printf("mh1= %f \n", mh1);

Then when you start EDEM from the command line with --no-free flag like:

"C:\Program Files\Altair\2025\EDEM\bin\edem.exe" --no-free

This will help identify what is happening in the code as the values will be written to the command line.

Regards

Stephen