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 Nintendo way of adapting technology is not to look for the state of the art but to utilize mature technology that can be mass-produced cheaply.
This is the reason a Nintendo console never has the fastest chips or the beefiest specs of its generation; instead, its remixes components in an interesting and generative way. Think of the Gameboy’s monochrome screen, the Wii’s motion controller, the Switch’s smartphone form.
[Gunpei Yokoi] is talking about reliability and predictability, in performance and supply alike. He wants the components to be boring, so their application can be daring.