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?
At its very core, the rules of the web are different than those of “real” markets. The idea that ownership fundamentally means that nobody else can have the same thing you have just doesn’t apply here. This is a world where anything can easily be copied a million times and distributed around the globe in a second. If that were possible in the real world, we’d call it Utopia.
…Resource Scarcity doesn’t make sense on the web. Artificially creating it here serves no other purpose than to charge money for things that could easily have been free for all. Why anyone would consider that better is beyond me.