Ray Traced Distance Field and alembic

hi all, iam testing alembic workflow unreal -blender is litle buggy but work

But I can not solve ,shadows with Ray Traced Distance Field not work

any ideas?

another test not shadow on alembic


thats because RTDF need a distance field to work wich is created ofline and i dont think the alembic imported assets have Distance field , correct me if im wrong i never used alembic before