Lambertian reflectance describes a surface that scatters incoming light evenly in all directions, so it appears equally bright from every viewing angle. Named for Lambert's cosine law, it is the idealized matte behavior of materials like paper, chalk, and unfinished wood. Most 3D reconstruction methods assume surfaces behave this way.
A Lambertian surface obeys Lambert's cosine law: the brightness it reflects toward a viewer falls off with the cosine of the angle between the incoming light and the surface normal, but it does not change with the viewer's position. Because the scattered light is the same in every direction, a perfectly Lambertian patch holds one fixed color regardless of where you stand.
Real materials are never perfectly Lambertian, but matte surfaces such as paper, plaster, and chalk come close. The model is widely used because it is simple and because it makes 3D reconstruction tractable. If every point looks the same from all angles, a feature photographed by two cameras can be matched and triangulated to a single, reliable 3D location.
The Lambertian assumption is the quiet foundation under most photogrammetry, structure-from-motion, and view synthesis. It is also the assumption that breaks. Materials that reflect or refract light (glass, metal, glossy plastic) violate it, and when they do, reconstruction places points in the wrong locations and rendering produces blur and ghosting.
Knowing where the Lambertian assumption holds, and where it fails, explains why some 3D captures look clean while others fall apart on the reflective parts. For teams deciding what to bring into 3D, it is a useful predictor of capture difficulty.
Miris is delivery infrastructure. Whether an asset is built from cleanly reconstructed Lambertian materials or from more difficult reflective ones, Miris conditions it once upstream and streams it adaptively to any device. The material physics of the source asset are decided before delivery, by the capture method and representation the asset owner chooses. Miris does not change how a material appears. It makes whatever representation was produced streamable. You own the asset. Miris owns the method of delivery.
Streaming video reshaped media consumption; we're doing the same for 3D. Join a small team solving tough spatial streaming, content delivery, and developer experience challenges.
Technical deep-dives on adaptive spatial streaming, the infrastructure challenges of 3D at scale, and what we're learning as we build. Written by the team doing the work.
