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?
Though you might not think it from the comic, I’m actually sympathetic to questions about tools and process, as I myself am a kind of process junky. I love hearing about how other writers work.
I’m also not someone who dismisses questions about tools with the line “the tools don’t matter.” In fact, I think tools matter so much that if you don’t talk about them correctly you can do some damage.
...What I love about John Gardner and Lynda Barry is that they believe that the tools you use do matter, but the point, for them, is finding the proper tools that get you to a certain way of working in which you can get your conscious, mechanical mind out of the way so that your dreaming can go on, undeterred.
You have to find the right tools to help your voice sing.