PerfectFacets — A Faceting Design and Optimisation Software for Lapidaries
PerfectFacets — A Faceting Design and Optimisation Software for Lapidaries
A computer-aided cutting design package used to model facet diagrams, evaluate light return, and produce cutting instructions
PerfectFacets is a faceting design and optimisation software package used by lapidaries to create, analyse, and document gemstone cutting diagrams. The program belongs to a small category of specialised lapidary tools — alongside GemCAD, Gem Cut Studio, and DiamCalc — that provide computer-aided design for gemstone cutting, replacing the older paper-and-protractor methods used by hobbyist and professional cutters before the personal-computer era. PerfectFacets allows the user to specify pavilion and crown angles for each facet, render the resulting stone in three dimensions, simulate ray traces to predict light return and brightness, and generate cutting instructions formatted for the standard faceting machine angle dial.
What it does
The user enters a faceting design as a sequence of facet entries, each defined by an index (the position around the stone), a cutting angle, and an azimuth. The software builds the resulting solid and renders it from any viewing angle, allowing the cutter to spot geometry errors before any rough is touched. The ray-tracing module calculates how rays of incident light interact with the stone's facets, returning a quantitative estimate of light return, scintillation, and the proportion of the table that returns light versus the proportion that windows.
For experienced cutters, the principal value of the software is design iteration. A cutter can sketch a custom design, test variations of angle and proportion, and converge on a cutting plan that maximises light return for the species being worked on, before committing rough to the lap. For commission work, the software produces printable cutting instructions and a rendered preview that can be shared with the client.
Position in the market
GemCAD, written by Robert Strickland in the 1980s, is the senior reference in the category and the program against which all later tools are measured. PerfectFacets is one of the alternatives that has emerged with newer rendering engines and updated user interfaces, aimed in part at the United States Faceters Guild membership and at hobbyist cutters who find GemCAD's older interface daunting. Gem Cut Studio, from MikeCutter, is another widely used package. DiamCalc, from OctoNus, is the diamond-industry standard for diamond proportion analysis and is used by laboratories and cutters working in the diamond trade rather than by general coloured-stone faceters.
The United States Faceters Guild publishes design libraries in formats compatible with GemCAD and increasingly with the newer tools, and competition cutters use the software both to design their entries and to verify that their finished stones match the published reference angles within the tolerances called for in the guild's rules.
In the workshop
For the working lapidary, software-assisted design has become the default workflow. Hand-drawn faceting diagrams persist mostly as historical and teaching artefacts. The transition mirrors what happened in jewellery design with the spread of CAD modelling and 3D printing of casting masters: the old craft skills remain useful, but the day-to-day work has moved onto a computer.