Keep all solid geometry GPU-resident during navigation. Use vertex-rate instancing, compact untextured vertices, vertex-cache ordering, and cached silhouette sources without culling geometry.
The shaded surface of a curved solid was visibly coarser than its own
wireframe: the wire ran along the true rim while the facets cut inside it.
Two things were wrong, and only one was the tolerance.
`facet_res` is a resolution multiplier — the same one `scale_lod` divides the
fallback sampler's chord fraction by — and the kernel path was using it as a
sag in world units. At the default that asks for a whole unit of departure, so
nothing smaller than a metre subdivided at all and a face was only ever as
round as its own boundary. It is a fraction of each surface's own radius now,
which carries no assumption about the drawing's units.
And it is the *edges'* fraction, shared from `EDGE_CHORD_FRAC` rather than
copied. Those edges are drawn over these faces; sampling the two differently
is what put the wire across a facet instead of along its corners. `facet_res`
is deliberately not applied either, since the edges it must line up with are
built once at highest detail and never scaled.
A torus is measured by its tube rather than its ring — the tube is the tighter
bend, and sampling to the ring leaves the section a hexagon.
The primitive-volume test claimed a mesh can never read over its true size.
That holds for a convex solid, where every chord lies inside; a torus is not
one, and across the inside of its tube the chords fall outside the material.
It passed before only because the sampling was too coarse to show it.
Co-Authored-By: Claude Opus 5 <[email protected]>
Faces were being dropped for sitting a nanometre off their own plane.
An edge is shared by two faces and in a real file cannot lie exactly on both:
the two surfaces were fitted separately and written to finite precision. Asked
for exactness, the kernel decides the edge is not on its plane, declines to
project it, and the face goes undrawn — silently, since a face that cannot be
expressed is reported as absent rather than as an error.
A micrometre in a drawing measured in metres recovers twenty-six walls of one
building. Loosening further buys almost nothing — a hundredth of this finds
one more face in sixty thousand — and past that it would start accepting
geometry that really is wrong, so it stops here.
With the tube fix that came with the kernel bump, VILLA_NEU_IFC3.dwg now
meshes 59015 of its 59033 faces, from 58922.
Co-Authored-By: Claude Opus 5 <[email protected]>
Hakan Seven