Two-dimensionnal (2D) radiation hydrodynamics codes are the workhorses with which current inertial confinement fusion (ICF) and high energy density (HED) experiments are most often prepared and analyzed. Yet significant scientific and programmatic benefits can be gained from a 3D capability. The TROLL code at CEA DAM is meant to address this need. This article illustrates the phases of integrated verification and physical validation through which this project is currently progressing.