Just released, 2,262 free NVIDIA vMaterials 1.7.0 Presets for DAZ Studio.
NVIDIA vMaterials are an official free 1.5Gb… “curated collection of MDL materials and lights representing common real-world materials”. MDL here means Material Definition Language, and this is said to be… “designed for physically-based rendering” (PBR). The materials are open source, so can be used in commercial renders, as can the new DAZ mega-bundle.
Judging by past partial conversions of earlier vMaterials packs, you will likely need to be rendering them with a recent iRay version — which means a recent version of DAZ Studio.