Bulk parts and panels

The component estimator uses principal axes and extent ratios to suggest panel or bulk treatment. Starting spacing is the largest principal extent divided by six, with a 20 mm floor. These are editable starting estimates.

Bulk parts normally use a CGAL alpha wrap. Automatic mode first checks whether a single closed CAD solid already matches its convex boundary within 0.001% volume. If that boundary has at most 96 vertices, it is used directly with outward-facing triangles. Surfaces, multiple bodies and cavities cannot use this shortcut. Otherwise automatic mode tries progressively coarser alpha/offset values, targeting at most 96 surface nodes; more than 240 is rejected. Interior mass samples allow inertia fitting without putting all mass on the collision boundary. The explicit convex option is available for appropriate shapes.

Panels use a grid in the principal plane and Delaunay triangles. Candidate collider triangles are clipped against the union of projected CAD triangles, so holes are not silently filled by a convex outline. Strongly curved panels are rejected by the planar template. Sparse depth locators give the sheet a volumetric numerical structure. Their mass is included in the fit, not added to the CAD total. Thin sheet mass fitting may use a bounded 1% tensor error to avoid nearly massless nodes. For a uniform panel with captured material properties, neighboring triangles also receive bending hinges. The plate rigidity is D = E t³ / (12 (1 − ν²)); each hinge uses D × edge length / centroid separation. Angular damping uses its effective nodal inertia. A coupled stiffness/damping screen reports any numerical reduction. This supplies bending restraint that nearly coplanar axial beams lack. It remains a provisional plate approximation, with no calibrated plasticity or fracture law.

The generated bulk/panel graph uses tetrahedral adjacency and a rigidity-rank check. Springs and damping have numerical caps. These component stiffness and failure values are provisional; a CAD mass fit is not material calibration.