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?
If something ships from one of the companies I advise, and it is virtually unusable because of poor design (which as we all know occasionally does happen), you can bet I go directly to the designer and ask how this happened? It is absolutely on the designer to ensure this does not happen, so something went wrong.
Similarly, if the product ships and performance is terrible you can bet I go directly to the tech lead with the same question.
And most frequently of all, if something ships and the analytics show that it’s either not being bought or not being used, or it turns out that it violates some business constraint like compliance or privacy, you can bet I go right to the product manager with that question.