Creating float64_t[2] attributes for alembic

Hi this is sort of a repost of this:

I’m hoping the more nuanced subject-title might shake some replies loose. :slight_smile:

Essentially I’m looking for information on how to create custom uv fields in alembic files. A colleague asked me to simplify a workflow they currently use for texturing hair exported from blender for use in UE’s groom system. Currently, they generate the hair, export it via alembic, then run a script on the alembic in Maya to add the property. The target is a classroom of students who are using blender.

Here’s what the result looks like from AbcEcho:

    CompoundProperty name=.arbGeomParams;schema=
      ArrayProperty name=groom_root_uv;interpretation=vector;datatype=float64_t[2];arraysize=10537;numsamps=1

that “float64_t[2];arraysize=10537;” bit looks like a 2 dimensional array structure.

As I mentioned in the other post, blender’s alembic documentation indicates that custom properties are currently added using the custom properties fields in the object properties, and that nested arrays are flattened into one dimensional arrays.

Does anyone have experience working with these types of structures in alembic, and might know how to go about working with them in blender?

Thank you