Coordinates, identity and CAD mass

Reference illustrations

publish-reference-skeleton.py (local source: tools/publish-reference-skeleton.py) reads the two tested manifests and verifies each source DAE hash before extracting its positions and triangle edges. It welds positions to micrometre precision for display, removes coplanar tessellation diagonals, and keeps creases and principal view silhouette edges. These are visible CAD outlines, not structural helper beams or collision triangles. Original manifest and mesh hashes accompany the bundled assets; there is no dependency on the old test folders at runtime.

Catalog hardpoint names map explicitly to the template’s suspension declarations, fixed mounts and shaft joints. A hub_axis is a second point relative to hub in this schema, not a direction vector. Unspecified housing axes remain missing. ReferenceSkeleton (local source: beamng.cad/UI/ReferenceSkeleton.cs) projects the illustration with an orbitable orthographic camera, draws the chosen part last for visibility, and overlays the requested markers and labels. The transparent wire illustration does not perform occlusion or physics simulation. Its controls have no CAD or project-write boundary, so reference browsing cannot apply example geometry.

Selection, coordinates and material intake

SelectionNormalizer (local source: beamng.cad/Preparation/SelectionNormalizer.cs) resolves component instances and persistent body references, deduplicates overlapping selections, and rejects stale or ambiguous references. A selected face resolves to its body. Whole-component expansion is explicit. Assembly transforms apply to each instance before converting SolidWorks (x,y,z) to BeamNG (x,-z,y). Metres and the assembly origin are preserved; the conversion occurs once.

The native material snapshot reads body assignments with part-level fallback. Solid mass comes from SolidWorks. Closed-mesh volume integrals supply COM and inertia, scaled to the native mass, for older exports. New native-property exports carry the body’s unit-density inertia and assembly transform separately from its display tessellation. Those exact CAD moments take precedence, so a coarse visual mesh does not change mass or inertia. Surface bodies use the exact triangle lamina moments plus symmetric thickness inertia: mass is CAD area × thickness × density. The tessellated surface area must agree with CAD within 1%. Combining bodies uses the parallel-axis theorem. See component geometry (local source: beamng.cad/FramePipeline/components.py).