Initialize Generated Coords
Initialize Generated Coords, found in the Tools section of the main DECALmachine panel is used, to prime decal objects for procedural texture usage, utilizing Generated Texture Coordinates.
While DECALmachine does only match plain materials automatically so far, you can Match Textures manually, if you need to.
Furthermore, if you want to match UVed Image Textures, used in the decal parent's material, you can use the Transfer UVs tool.
One or multiple Decal objects.