A session is most productive when the preparation package is complete before the call opens. The foundation of any engagement is a geometric file of the relevant head scan or base form — the anthropometric starting point from which all coverage, offset, and proportion decisions are made. Head scans can be supplied in standard mesh formats; where a customer is working to a known standard headform rather than a specific individual scan, that reference can be supplied or selected from available standards in advance of the session.
Thickness specifications for protective and comfort layers are the second critical input. These define the envelope between the headform and the outer shell — the space that foam, padding, retention systems, and any structural liner must occupy. Supplying these as explicit dimensions, even approximate ones, allows the parametric system to resolve the outer shell geometry to a realistic starting proportion from the first iteration rather than working backward from a styling surface that may not accommodate the required build-up.
Silhouette references and sketch inputs define the design intent. These can range from refined plan-view orthographic sketches to loose directional references, mood images, or annotated photographs of existing helmets in the market. The technician uses these to orient the parametric model toward the customer’s aesthetic direction before the session begins. Pre-existing 3D models or CAD files, where available, can also be supplied as reference overlays — useful for customers developing a new geometry that must maintain family resemblance to an existing product line or fit within an established design language.
None of these inputs need to be final or fully resolved. The session is a working environment, not a handoff. Customers who arrive with a complete preparation package move faster and cover more ground, but the parametric system is designed to respond to direction as it develops. Partial references, open questions, and undecided constraints are normal starting conditions. The preparation package defines the floor; the session determines how far above it the geometry goes.