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?
"Every website that’s made me oooo and aaahhh lately has been of a special kind; they’re written and designed like essays. There’s an argument, a playfulness in the way that they’re not so much selling me something as they are trying to convince me of the thing. They use words and type and color in a way that makes me sit up and listen.
And I think that framing our work in this way lets us web designers explore exciting new possibilities. Instead of throwing a big carousel on the page and being done with it, thinking about making a website like an essay encourages us to focus on the tough questions. We need an introduction, we need to provide evidence for our statements, we need a conclusion, etc. This way we don’t have to get so caught up in the same old patterns that we’ve tried again and again in our work.
And by treating web design like an essay, we can be weird with the design. We can establish a distinct voice and make it sound like an honest-to-goodness human being wrote it, too."