From render to 3D production files: the spec gates before export
mulapis Research
A 3D production file is a three-dimensional model that can be handed directly to casting and fabrication. It differs from a render in its goal: the render's job is to show the design accurately; the production file's job is to make it buildable. At mulapis, once a design is confirmed, the engine exports production files directly, with no manual remodeling in between — but before export, the model must pass the specification gates below.
Wall thickness and minimum feature size
Casting has physical floors: walls below the minimum starve the metal flow, and details below the minimum never take shape. The band, the prongs and the milgrain beading each carry their own minimum size, and every region of geometry in the file must clear its floor — a hard, local constraint checked point by point, not a judgment of overall appearance.
Every stone needs a seat
In a render, a gemstone can simply rest on metal; in a production file, it must be set in metal. Every stone maps to a seat with support underneath, prongs or channels to hold it, and a hole drilled to the stone's actual diameter and depth. A pavé design with dozens of side stones means dozens of seats, each of which must individually work.
Ring size and room to resize
A ring size converts to an exact inner diameter — size 14 is 17.3 mm. The production file must hit that number, and also leave room for future resizing: the shank should tolerate going up or down half a size to a size without touching the stone seats.
Gold weight comes from volume
A production file is a closed solid, so its volume is determinate; multiply by the alloy's density and you have the gold weight. Once the volume exists, material cost follows immediately. Gold weight sits on the spec because it derives directly from the geometry — not a number back-filled by guesswork.
Integrity of the file itself
A model delivered to production must be a watertight mesh: no open faces, no overlapping surfaces, correct units and scale. File-level defects never show in a render, yet they fail downstream fabrication outright — the class of problem most easily missed and latest discovered.