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?
The first task for growing designers, as opposed to managers, is to craft a proper career path for them, one whose compensation and sociological status reflect their true value to the creative enterprise. This is commonly called the dual ladder. It it easy to give corresponding salaries to corresponding rungs, but it requires strong proactive measures to give them equal prestige: equal offices, equal staff support, reverse-biased raises when duties change.
Why does the dual ladder need special attention? Perhaps because managers, being human, are inherently inclined to consider their own tasks more difficult and important than design and need to deliberately assess what makes creativity and innovation happen.