Changing the path of the resources (.tudat/resource) folder Tudat uses

[boramenekse]

Hi,

I have a project in C++, which uses Tudat, and I export it to a project in Unity by creating a single dynamically linked library file (dll) that has both the Tudat source code and my project's source code. In order to make the interface work, I need to export all the dependencies Tudat needs, including the resources folder (.tudat/resource). When I have the resources folder in my home directory, everything works fine, but I want/need to have that folder in the Unity project for the sake of simplicity for end-users who will use the product of the Unity project.

Therefore, I am trying to change the path of the resources folder Tudat uses, but I haven't succeeded. I have tried modifying a function in the resource.h file as follows:

static inline std::string get_hidden_path() { 
  const char* resourcesPath = getenv("TUDAT_RESOURCES_PATH");
  char buffer[MAX_PATH];
  
  if (resourcesPath != nullptr) {
    std::cout << "Entered the if" << std::endl;
    std::cout << resourcesPath << std::endl;
    snprintf(buffer, MAX_PATH, "%s", resourcesPath);
    return std::string(buffer).c_str();
  }

  std::cout << "Did not enter the if" << std::endl;
  return std::string(get_homedir() + "/.tudat").c_str();    // originally, the function had only this line
}

But the source code still searches for the .tudat folder in the home directory.

Is it possible to change the path of the resources folder Tudat uses? If so, what steps should I take to make that change?

[DominicDirkx]

An important point to understand here is that this function is not part of the tudatpy repository, but part of the tudat-resource repository which is a dependency of tudat. We have an issue open to move all this to tudatpy and remove this separate dependency, but we're not there yet. But I think the general approach you have is correct, by changing this function. The problem may be that when exporting it, it's not being used since it's not part of the tudatpy repo.

[boramenekse]

I just realised that I didn't rebuild Tudat, so the Tudat source code was using the original version of that header file :(

I'll try it again tomorrow by rebuilding Tudat first, and it would probably work because, as far as I have discovered, all paths follow from the output of the get_hidden_path() function in resource.h

Is this actually true, or are there any paths that might be hard-coded to the home directory?

[DominicDirkx]

For retrieving the data resources, they should all be linked to get_hidden_path

[boramenekse]

Perfect, then it was a silly mistake on my end probably, sorry. I'll keep you updated about the outcome when I try it again with a new build of Tudat

[boramenekse]

As promised, I am writing to let you know that it works fine now with a rebuild of Tudat. In case anybody might need to do the same thing, the full procedure I followed is:

• Set a system environment variable with the name TUDAT_RESOURCES_PATH and the absolute path of the .tudat folder as its value
• Modify the get_hidden_path() function in the file resource.h using the code I shared above, and only delete the .c_str() in line return std::string(buffer).c_str(). The header file should be in the directory %CONDA_PREFIX%/Library/include/tudat/resource.
• Rebuild Tudat

You'd need to reopen any terminals and probably the code editor you use after setting the environment variable so that the change can take effect in them.

[valeriof7]

Thanks for the feedback! We will try to include this information in the most appropriate section of our user guide and/or API.