Summary
We completed M3 and M4: the geometry and verification baselines. Forge can now read a STEP assembly, preserve the identity of its parts, calculate measurements from the engineering geometry, and keep a traceable record of where every number came from. Those facts then pass through one ordered verification process before they can support an engineering decision. In plain terms, Forge has moved from understanding what a CAD file contains to showing why a geometry claim can be trusted. A clearance is no longer just a number on a screen. It carries the source model, model version, units, measured parts, calculation method, and review path behind it. We explain that chain in How CAD Becomes Engineering Evidence.What we shipped
Milestone M3 (complete).- A real STEP geometry path: STEP is a neutral exchange format used to move 3D engineering models between CAD systems. Forge now reads STEP assemblies locally and preserves each occurrence of a component as its own traceable object. This matters when the same part appears in several locations: each installed occurrence can have a different relationship to the surrounding ship.
- Measurements with receipts: volume and component-to-component clearance are calculated from the model and stored as measurement records. A measurement record is the engineering equivalent of a receipt: it preserves the value, unit, source file, model version, measured objects, and method used.
- Clearance, contact, and clash kept distinct: a positive clearance means space exists between two parts. Zero means they touch. An overlap is raised as a clash for engineering review rather than being converted into a misleading number.
- Known-shape verification: before relying on imported vessel geometry, we checked the calculation path against shapes and assemblies with known dimensions and answers. This gives the geometry service a repeatable reference point.
- Import uncertainty stops the measurement: if units are missing or contradictory, scale is ambiguous, or repairing the file could change the shape materially, Forge pauses measurement emission and asks for review. It does not turn an uncertain model into an authoritative number.
- A deliberately narrow IGES path: IGES, an older CAD exchange format, is supported as a compatibility route for single solids. STEP remains the primary assembly path because it preserves the structure and identity needed for governed engineering work.
- One verification ladder, T1 through T7: every formal output follows the same sequence of checks. T1 confirms sources and citations; T2 checks whether the rule fits the vessel context; T3 makes confidence and assumptions explicit; T4 confirms that geometry claims cite real measurement records; T5 is responsible-engineer review; T6 brings in class or USCG review where required; and T7 records the final signed decision. See L6 · Verification Ladder for the complete explanation.
- Confidence is visible: T3 requires a usable confidence value and clearly stated assumptions. This allows reviewers to distinguish a well-supported conclusion from one that depends on information the project has not yet confirmed.
- Geometry claims remain attached to evidence: T4 checks that every cited measurement exists, belongs to the same vessel and model scope, and supports the claim being made. A bare number or an unrelated measurement cannot pass.
- Quality targets now govern capability: citation accuracy, applicability, missing-evidence detection, refusal quality, geometry grounding, isolation, and replayability are measurable requirements. They determine how much responsibility a capability can earn. The public thresholds are listed in How We Measure Quality.
What we learned
- A geometry engine alone does not create trust. Trust comes from the full chain: file identity, units, assembly position, calculation method, measurement record, citation, and accountable review.
- The visual model and the engineering evidence serve different purposes. A light display model helps people inspect and discuss the ship. Measurements must continue to come from the engineering geometry and remain linked to their source.
- Uncertainty is most useful when it is explicit. Pausing on ambiguous units or risky model repair gives the engineer a clear question to resolve before uncertainty travels into downstream work.
- A shared verification sequence creates a common language. Engineers, naval architects, class reviewers, and program leaders can see which checks have passed, which review is next, and what evidence supports the result.
Blockers & open questions
- The geometry baseline is ready to be exercised with partner model conventions. Each yard names assemblies, parts, zones, and revisions differently, so partner onboarding will map those conventions into Forge while preserving the yard’s existing source of truth.
- STEP is the primary governed path. ShipConstructor, AutoCAD, CADMATIC, and other system-specific connections will be enabled with each partner where access and permissions allow, rather than assuming that one connector fits every yard.
- We are committed to enlarging the rule and interpretation corpus as the product surface grows. This lets each new workflow be exercised against a broader range of regulatory and yard-specific evidence while keeping every interpretation traceable.
- The verification ladder creates a consistent review path. Partner and class feedback will help us calibrate how that path appears in day-to-day workflows without changing who holds engineering authority.
Next week
- Bring the geometry and verification foundations into the controlled DesignOS pilot: turn cited gaps into build-readiness views, show recorded change impact, prepare review packages, and place the evidence directly on a CAD-aware review surface.