• Copper roof cladding with verdigris corrosion. Discoloration is driven by a single fBm patina mask that controls all four maps in lockstep — colour, metallic, roughness and surface relief — so the green patches read as physical corrosion rather than a tinted paint.

    • Color lerps from aged copper through bright verdigris flake to deep patina as the mask climbs through patinaCoverage.
    • Metallic flips from 1.0 (bare copper, tinted Fresnel reflector) to 0.0 (verdigris, a copper-carbonate dielectric) across the same threshold.
    • Roughness climbs from copperRoughness to patinaRoughness so the patinated patches kill the IBL specular and look matte.
    • Normal combines a standing-seam ridge field with the fBm micro-relief, then bumps the patina patches further. Seams run along the V axis (down-slope), the convention for traditional batten-and-seam copper roofing.

    Parameters

    Returns MaterialMaps