In optics, a caustic is the envelope of light rays reflected or refracted by a curved surface or object, or the projection of that envelope of rays on another surface. The caustic is a curve or surface to which each of the light rays is tangent, defining a boundary of an envelope of rays as a curve of concentrated light.
A piece of milled plexiglass acting as a projecting lens; via the Computer Graphics and Geometry Lab at the École Polytechnique Fédérale de Lausanne
New milling techniques applied to glass and plexiglass panels could be used to “create windows that are also cryptic projectors, summoning ghostly images from sunlight.”
[Pauly and Bompas] hope that the technique will be used in architectural design, to create windows that mould sunlight and throw images or patterns onto walls or floors,” which, if timed, milled, and manipulated just right, could produce a slowly animated sequence of images being projected by an otherwise empty window during different times of day.
To control the shape of a caustic pattern generated by a specular or refractive surface, we need to solve the inverse problem: how can we change the surface geometry, such that incident light is redirected to produce a desired caustic image?
Glass looks and feels perfectly tailored to my photo sharing needs and expectations. For me it’s even better than pre-Facebook Instagram in the sense that it pushes me to select and share what I think are good photos (same as it happens with Flickr), rather than making me obsess with getting ‘the Instagram shot’ at all costs every day or multiple times in a day. It doesn’t cheapen photography like Instagram has done for years.
That’s why I hope Glass’s founders/developers will resist feature creep. Resist user objections like: I don’t think Glass is offering that much for the subscription price they’re asking. There are a lot of people who will gladly pay for having a cleaner, simpler, focused experience.