Blender 2.8: smoke data empty, e.g. density_grid

I contribute in the developement of the exporter for LuxCoreRenderer and when I try to read the data of a smoke simulation, the length of the data arrays are empty.
len(mod.domain_settings.density_grid) returns 0 even when the simulation has been baked and the smoke is visible in the viewport. @brecht Is this a bug or how can the data be accessed in Blender 2.8?

Are you reading the data from the evaluated object?

As far as I know the volume grid data should exist in the objects you get from iterating over the objects and instances in the dependency graph.

Hi @brecht,
thanks for the quick response. With the evaluate object it returns the correct data. Thanks for the help.