[mj_parseXMLString] How to specify mjSpec.modelfiledir

[Tadinu]

Intro

Hi MuJoCo team,
I am a graduate student, trying to programmingly load robot model from separate component XML files.

My setup

MuJoCo 3.2.7, C, Ubuntu 22.04

My question

mj_parseXML allows a filename to be specified, from which the output spec's modelfiledir as the parent folder is determined through FileGetDir().

However, for mj_parseXMLString, since only the direct XML string is received, is there a way to specify modelfiledir in order to load an XML string that includes a relative path to another XML file?
If no, so does it mean we have to use an absolute path for the included file?

Thank you!

Minimal model and/or code that explain my question

No response

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.

[quagla]

I think this https://github.com/google-deepmind/mujoco/blob/main/test/xml/xml_native_reader_test.cc#L1618 is an example of what you are asking for?

[yuvaltassa]

The OP was not clear if they are using <include> or <attach>...

[Tadinu]

Oh thanks a lot, so using <attach> instead is a nice and more flexible alternative it seems, tho I meant <include> actually.
Specifically, I'm trying to load this scene.xml using mj_parseXMLString in an effort to mimic in C what is done here in python using dm_control's mjcf.
Of course, using mj_parseXML() works very well already, so the question is mostly for clarification.