Why metal needs PBR: realistic jewelry rendering on a screen
Jewelry is mostly reflective surface. A flat color or a baked-in highlight reads as a sticker in under a second. Physically based rendering (PBR) combined with image-based lighting from the shopper actual environment is the minimum bar to make a metal piece look like a metal piece on a screen.
The flat-texture failure mode
Most early web AR for jewelry rendered a piece as a flat texture pasted on the camera feed. The texture had a hand-painted highlight, sometimes a baked reflection. The result was uncanny in a specific, identifiable way: the highlights did not move when the wrist moved.
Eyes are good at spotting this. A polished metal in real life has reflections that track the room and the viewer; if those reflections sit still while the rest of the scene moves, the brain registers the piece as a sticker.
What PBR actually does
Physically based rendering describes a surface by its real physical properties — metalness, roughness, index of refraction, normal map, base color — then evaluates how light interacts with it using a microfacet model. The same material reacts to the lights in the scene the way the real material would.
On its own, PBR with a generic studio environment is already a step up. But the strongest move is image-based lighting derived from the shopper own camera feed: the environment map is rebuilt from what the camera sees, several times a second, so reflections track the actual room around the piece.
Metal type matters
Yellow gold, white gold, rose gold, sterling silver, and platinum each have distinct reflectance and color. A single chrome material does not stand in for any of them. The right path is a curated PBR preset per metal type, applied consistently no matter where the geometry came from — hand-modeled, photogrammetry, or AI image-to-3D. The geometry can vary; the material reading as metal is the brand promise.
Gemstones and anisotropy
Diamonds need refraction and dispersion. Sapphires shift hue with lighting angle. Pearls have lustre — a soft, layered reflection. Brushed metal has anisotropy, where the highlight stretches along the grain. These details are not nice-to-haves on a screen at $1,000+ AOV; they are the difference between a believable piece and an obvious render.
The honest floor
PBR with image-based lighting is the minimum for jewelry AR. It is not a competitive moat — it is the baseline. The moat is the consistency of that bar across every SKU a brand uploads, regardless of how the geometry was created.