Rule A (area-sorted triangle removal) left holes and open boundaries
on closed meshes (visible artifacts when zoomed far out). The decimator
is now a proper quadric edge collapse:
- Collapse: welded u32 topology, per-vertex quadrics (accumulated
incident face planes), edge cost = quadric error at the optimal
point (clamped to the segment) + edge length, BinaryHeap with a
custom Ord (f32 is not Ord; inverted compare, NaN-safe).
- Standard GH semantics WITHOUT the new face: both incident pair faces
degenerate and are removed; neighbouring faces remap and sweep over
the region. Preserves the Euler characteristic and closedness (no
holes, no books, no duplicate faces); interior collapse = -2 faces,
boundary = -1. Guards: non-manifold edge (>2 faces) or a fold
(duplicate sorted triple) rejects the collapse.
- welded(): fuzzy welding (1e-6 relative tolerance, grid + 27-
neighbour broad phase, exact verify) - trig-generated seams differ
by ~1e-16, exact-bit welding missed them.
- Root causes fixed along the way: dead face slots are never reused
(stale edge/vface entries), vfaces updated on remap, degenerate
faces dropped, best-effort target (granularity -2/-1 can land 1-2
off; soft cap, deterministic).
- Docs: DRAFT D10, ROADMAP 4.3, ARCHI_CPU_GPU, gpu-driven, lib
README, mesh/scene/demo comments - 'greedy decimation / Rule A'
replaced by 'quadric edge collapse'.
- lod.rs test: deprecated glam perspective alias -> explicit
glam::camera::rh::proj::opengl::perspective.
cargo test --workspace: 100 passed (94 lib + 3 wgsl + 3 integration),
0 failed; demo runs clean with LOD on.
Bug fixes found while validating stage 15:
- demo: set_shadow_caster(Some(0)) selected the default +Z light (packed
index 0 from Lights::new()); the demo's warm directional light is packed
at index 1. The shadow camera then looked down -Z, so misaligned objects
occluded each other (cone/torus rendered black). Use index 1.
- primitives::torus: index winding was flipped ([a,c,b]); the outer surface
(outward normals, CCW from outside) was culled and only the dark interior
stayed visible. Reversed to [a,b,c]/[b,d,c] so it is CCW from outside.
- app: call device.poll() each frame in about_to_wait; without it wgpu
async callbacks (on_submitted_work_done, map_async) never fire in the
windowed loop.
Docs:
- conf: clarify the embedded-shader fallback is expected/harmless and that
SHADOW_SHADER_PATH is kept for API compatibility only.
- README item 15: runtime-verified headless.
- DRAFT.md: emptied to a completion summary per convention (full stage-15
plan preserved in git history).
Add resources::CameraController (Etapes 15.C): spherical yaw/pitch/distance/
target with orbit() (mouse drag), zoom() (wheel, clamped), reset(), and
apply_to(&mut Camera). Add Scene::camera_mut() for in-place per-frame edits.
New lib/examples/demo.rs: all six primitives on a textured ground, standard
Phong material, shadow-casting directional + point + spot lights, and a live
orbital view driven by the unified input (drag=orbit, wheel=zoom, R=reset,
1/2/3=front/side/top presets) plus slow primitive rotation.
6 unit tests for CameraController.
Jérôme Bousquié