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?
Too often, a popular consumer app unexpectedly gets worse: Some combination of harder to use, missing features, and slower. At a time in history where software is significantly eating the world, this is nonsensical. It’s also damaging to the lives of the people who depend on these products.
...Maybe we ought to start promoting PMs who are willing to stand pat for an occasional release or three. Maybe we ought to fire all the consumer-product PMs. Maybe we ought to start including realistic customer-retraining-cost estimates in our product planning process.
We need to stop breaking the software people use. Everyone deserves better.