EDEM CUDA API：How to specify particle names in an EDEM CUDA file

Longzhu

I have developed an EDEM body force API whose function is to apply force to particles named "FIX". My API code is correct, but I encountered an issue when writing the .cu file—the .cu file fails to recognize the particles named "FIX". I would like to ask how to implement this function in the .cu file?

I have attached my code.

Stephen Cole

Hi,

CUDA doesn't support strings so you have to identify the names on CPU and pass this to the GPU as an integer.

For example in

https://community.altair.com/discussion/34950/edem-api-contact-model-example-removing-particles

We remove particles that contact a specific named geoemtry.

In CRemoveParticles.cpp we set a parameter value to 1 in the CPU if it's the required geometry name. In the code below we're checking geometryName.c_str() which is a user input, but you could equally use "FIX" as a string instead.

std::string temp = geometryType;

std::string geometryName = GEOM_NAME.getString();


if (strcmp(temp.c_str(), geometryName.c_str()) == 0)

{

    params[0] = 1;

}

else

{

    params[0] = 0;

}

return sizeof(double);

and this parameter gets passed to the GPU so we can check for this parameter:

// Check if the particle is in contact with the geometry

real geometry = CUtilitiesPrecision::convertToReal(*(double*)(element2.getParameterData()));


if (geometry == REAL_CONST(1.0))

{…}

Regards

Stephen