Preface

Welcome to ProFacet!

ProFacet works a bit differently than other tools. Under the hood, every design is defined by a text-based "recipe" called FSL (Facet Specification Language).

You don't have to write this code yourself. As you work with the visual tools like the Interactive Slicer, ProFacet writes the FSL for you automatically. You can create entire designs just by clicking and dragging.

However, this recipe is always there, visible and editable. This means you have the best of both worlds: the ease of a visual interface and the precision of a text definition. You can switch between them at any time. While you can operate the tool entirely through the UI, most users find that they naturally start using both: the UI for the heavy lifting and the code for quick tweaks or precise adjustments.

Design Goals

ProFacet was born from a conviction that gemstone design software can, and should, be better. Every decision in the project is guided by the following principles:

Scientific Rigor. Optical performance analysis in ProFacet is held to the standard of a scientific instrument. Every metric (brightness, contrast, scintillation, and the rest) is defined precisely, calibrated against a known reference, and computed without shortcuts.

Realistic Results. Most existing tools produce renderings where the contrast looks noticeably different from what a real stone looks like. The primary culprit is unrealistic lighting, in particular the widespread use of head shadow, a lighting convention so far removed from how light actually behaves in the real world that it is almost comical. That said, head shadow is not without merit: by blocking the direct return path, it forces the design to prove it can gather and redirect light from oblique angles, which is a genuinely useful diagnostic. ProFacet respects this duality. It offers rigorous analytical lighting and a physically-based path tracer so that the rendered image converges on what you will actually see when you hold the finished stone in your hand.

Engineering Excellence. ProFacet is built as a professional-grade engineering product. The codebase follows strict quality standards: modular architecture, comprehensive testing, and clean abstractions. Reliability is not optional when your users are about to commit an expensive piece of rough to the wheel.

A Cutting-Edge Optimizer. The built-in optimizer is not an afterthought. It is a first-class subsystem that can explore a vast design space, tune every parameter simultaneously, and converge on solutions that a human would be unlikely to find by hand. It is the engine that turns a good design into a great one.

Blazing Speed. Performance is a core requirement, not a nice-to-have. Ray tracing, metric computation, and optimization all run at speeds that keep the feedback loop tight and the creative flow unbroken, even on modest hardware, thanks to massively parallel GPU execution.

Parametric Design. Every ProFacet design is defined by a parametric recipe written in FSL (Facet Specification Language). This means a single design file can express an entire family of stones: vary the angles, adjust the proportions, change the symmetry, all from one specification. It is the reason FSL exists, and it unlocks workflows that point-and-click tools simply cannot offer.

Beauty. A tool for designing beautiful objects should itself be beautiful. From the rendered stone previews to the documentation you are reading right now, ProFacet aims to be a joy to look at and a pleasure to use.

Documentation Structure

Because the coding part is optional, we've organized the documentation into two parts:

• Part 1: The Studio covers the visual tools you need to design and cut. This is all you need to get the job done.
• Part 2: FSL Reference covers FSL, the powerful language underneath. It serves as an alternative to the UI, especially useful for precise manual adjustments or advanced parametric designs.

If you're interested in learning how to read or write the recipe directly, or want to use advanced algorithmic features, check out Part 2. Otherwise, feel free to stick to Part 1 and just cut!

Contact

If you have questions, feedback, or need support, join our Discord community.

Timeline

• Milestone 1 (Reached): The foundation is rock solid—we created and optimized more than 11,000 designs with success. Browse the Design Portfolio to see for yourself. We are currently improving usability and finishing experimental features like the photo-realistic bi-directional path tracer.
• Contest Window: Probably around 1 Jan 2027 — run the launch performance contest.
• Paid Phase: begins after the contest—introduce billing for the Analyzer, Optimizer, Path Tracer and Cloud Sync. The "offline" mode without these tools will stay free to use.