Covers the pure-logic modules with no Qt event loop or GL context: BVH
build, LOD decimation, sidecar round-trip, instanced-geometry layout
constants, and Federation save/load + relative-path policy. Each test
binary compiles only the production source(s) under test, so the unit
tier doesn't pull Qt/OpenCASCADE/IfcGeom into the test build.
Gated behind BUILD_IFCVIEWER_TESTS=OFF; default builds remain offline.
Catch2 v3.5.4 is fetched on demand via FetchContent.
Turn src/ifcviewer into libIfcViewer.so holding the rendering engine +
geometry pipeline (ViewportWindow, GeometryStreamer, BvhAccel,
InstancedGeometry, SidecarCache, LodBuilder, AppSettings). Move the
existing UI shell (MainWindow, SettingsWindow, main.cpp) into
src/ifcviewer-full as the IfcViewerFull executable. Add a new
src/ifcviewer-minimal target with a MinimalWindow that hosts only the
viewport and reuses the sidecar fast-path for benchmark/debug runs.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Use $<TARGET_FILE_DIR:IfcGeom> instead of hardcoded
${CMAKE_BINARY_DIR}/ifcgeom/$<CONFIG> for plugin runtime dirs — the
old path was wrong on non-MSVC generators where $<CONFIG> expands
empty. Add explicit add_dependencies for kernel/mapping plugins so
IfcViewer waits for them to build, and drop the redundant direct link
against ${kernel_libraries}.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Decimate each unique mesh once at sidecar-build time and swap to the
reduced index slice per-instance per-frame when projected sphere radius
drops below IFC_LOD1_PX (default 30). Same VBO, same SSBO, just a
different firstIndex/count in the indirect command.
Extends MeshInfo (48→56 B) with lod1_ebo_byte_offset + lod1_index_count
and bumps the sidecar to v5. buildLods() runs inside
onStreamingFinished, appends decimated indices to sd.indices,
applyLodExtension pushes the EBO suffix to the live GPU state, and the
sidecar is written with LOD1 baked in.
simplifySloppy (voxel clustering) is used instead of the default
edge-collapse meshopt_simplify because BIM brep output is per-triangle-
unwelded and non-manifold after welding — simplify returned the input
unchanged for every mesh tested. Sloppy ignores topology. Knobs
(IFC_LOD_SLOPPY, IFC_LOD_ERROR, IFC_LOD_RATIO, IFC_LOD_MIN_SAVINGS,
IFC_LOD_LOCK_BORDER, IFC_LOD_DEBUG) are available for A/B tuning.
Result on the 128M-tri 10-model test scene (GTX 1650, 2px contribution
cull): 20.2 → 43.2 fps, 40M → 14M visible triangles, no change in
object count. LOD build adds 100–600 ms per model on first open,
cached thereafter.
README Phase 3B section is now a full writeup of pipeline, selection,
decimator-choice rationale, env vars, and measured numbers.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Dion Moult