forked from 1b-agent/opencadstudio-upstream
Every 3-D solid OCS makes or opens now goes through cadkernel, which holds analytic surfaces — a cylinder is a cylinder record, not a spline that looks like one. That is what lets a solid built here be written back out as exact ACIS instead of a triangulation, and a facetted export is a one-way door: the next application to open the file would have no way back to the circle. The Model tab's seven primitives, the Design-group booleans, 3DROTATE, 3DMIRROR, 3DALIGN, SLICE, SECTION, POLYSOLID and PYRAMID all come from the kernel now, and `scene.solid_models` holds a `Body`. A mirrored solid needed its own care before; the kernel reverses the loops on the way through, so it comes back the right way out rather than lighting black. EXTRUDE and REVOLVE sweep the profile `entities::curve` already defines, so a circle, an arc-bulged polyline and a closed spline arrive as the same thing. A circle extrudes into four cylinder patches rather than a run of chords, and a profile turned about an axis becomes a cone, a sphere or a torus. A spline profile has no analytic side wall and is refused rather than approximated. ACIS goes both ways through the codec's own bridge: `lift` to read and `append` to write. That drops the 679-line truck conversion and the planar- only exporter, and the tessellator keeps its bespoke sampler as a fallback for whatever the kernel cannot yet express — reported rather than passed off as whole, since a mesh missing a wall looks finished. truck-shapeops is no longer used and is gone from the manifest. truck-modeling stays for now: fourteen files use it as a 3-D NURBS evaluator, which the kernel has no answer for yet, and SWEEP and LOFT have no kernel operation behind them either. The two `automation` test failures are unchanged from before this and are not caused by it. Co-Authored-By: Claude Opus 5 <[email protected]>