Foundation for streaming. Adds to each Chunk:
- is_resident (default true; streaming flips false initially)
- vertex_byte_offset / vertex_byte_size in the sidecar file
- aabb_min / aabb_max world-space chunk bounds (used by future cull
and streaming priority)
Plus on the model:
- streaming_file_path (non-empty = streaming path was used)
- streaming_vertex_section_offset (where the chunks live in the file)
All fields default to backward-compatible values: is_resident=true,
streaming_file_path empty. The existing non-streaming applyCachedModel
sets up a Chunk with is_resident=true (implicit) and ignores the
streaming fields, so no behaviour changes yet.
Commit 3/4 wires the metadata-only reader from (1/4) through a new
applyCachedModelStreaming path that flips is_resident=false initially;
commit 4/4 adds the per-frame loader that brings chunks resident on
demand. This commit is verified pixel-identical to the previous render
on basic.ifc.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
First foundational piece for task #16. WgpuStreamingLoader exposes:
- readSidecarMetadataOnly(path): reads v13 header + mesh dict + instance
dict + georef + elements + string table from disk. Skips the bulky
vertex and index byte sections, recording their on-disk offsets so
they can be range-read later (per-chunk, on demand). The file handle
is closed before return.
- readSidecarVertexChunk / readSidecarIndexChunk: open + fseek + fread
for a byte range. Synchronous; intended to be called from a worker
thread for true async streaming or the main thread for stage-1
on-demand load.
No format change yet — operates on existing v13 sidecars. v14 with an
explicit per-chunk TOC arrives in a follow-up; this layer abstracts
the chunk boundaries so the upgrade stays internal.
No integration with existing applyCachedModel — that's commit 3/4.
Build verifies the API compiles and links into IfcViewerWgpu.
Commits in this series:
1/4: metadata-only reader (THIS)
2/4: per-chunk residency state on WgpuModelGpuData
3/4: --streaming opt-in path through applyCachedModel
4/4: per-frame chunk-on-visible loader (the OOM fix)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 15 implementation lands but doesn't pay off as default-on. On a
562k-instance / 18-model scene with a centred camera, the BVH walk
adds ~10 ms of cull cost without rejecting enough subtrees to
compensate — every interior node's AABB straddles the frustum, so
descents go all the way to leaves anyway. Linear scan beats it by
that 10 ms.
GL's BVH works better mainly because they do full cull (frustum + HiZ
+ contribution) at every node — their per-test cost is lower (likely
SIMD-vectorised) and they get more subtree rejections. My current
impl does frustum-only at interior nodes (HiZ there cost more than
it saved on the smaller dataset).
For now, gate the whole BVH walk behind --bvh, default off. The
infrastructure (BvhAccel build at applyCachedModel, walk in cull,
release) stays in place so it's a one-flag toggle to measure either
side. Real default-on requires further tuning — see updated task #15.
Measured on 562k-instance scene:
--bvh on → 25.9ms total (cull 25.4ms)
--bvh off → 15.4ms total (cull 14.5ms) ← default
For comparison, GL on the same scene + camera:
GL → 18.2ms total (cull 8.5ms wall, multi-threaded BVH)
Net: wgpu beats GL by ~3ms total despite slower cull, because the
GPU side (no edge-pass cost, async HiZ readback, lean main pipeline)
gives back more than the cull deficit.
Also added task #17 (GPU compute-shader cull) as the asymptotic
answer — both backends hit CPU cull as the ceiling on ≥500k scenes;
moving it to a compute shader drops it to sub-ms regardless.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two pieces:
1. Per-chunk vertex storage (stage 13)
WebGPU mandates maxStorageBufferBindingSize ≥ 128 MB. Real BIM models
routinely exceed that (one of yours is 139 MB vertex). Without
chunking, every browser load would fail with
"exceeds max_storage_buffer_binding_size".
Strategy: each model's vertex data is split into ≤ 128 MB chunks at
applyCachedModel time. Each chunk gets its own vertex_storage buffer,
visible_draws / prefix_sums buffers, per_chunk_uniform, and bind group.
Index buffer, instance storage, and mesh storage stay single-per-model
(they fit well under the cap on every scene we've seen). Mesh-to-chunk
assignment is bake-time-deterministic (walks meshes in order, opens a
new chunk when adding the next would overflow).
Cull buckets visible instances by their mesh's chunk; render issues
one drawcall per non-empty chunk per model. WGSL is unchanged — the
binary-search vertex pulling works identically per chunk because
base_vertex is now CHUNK-LOCAL (the chunk's bind group binds its own
vertex_storage).
Single code path: chunking is ALWAYS on at 128 MB regardless of
target. Cost on desktop is a handful of extra drawcalls per frame
(1 per non-empty chunk; typical models = 1-3 chunks). Negligible.
A mesh whose vertex range is itself > 128 MB can't fit in any chunk
and would need splitting — typical IFC meshes are nowhere near that
(hundreds of verts), and applyCachedModel warns loudly if one ever
appears.
--web-limits CLI flag requests the WebGPU mandatory floor limits
(128 MB max storage binding, 256 MB max buffer) instead of the
adapter's actual max. Used to verify chunking actually fits through
browser constraints — turns "trust me, web will work" into a hard
test. The 139 MB scene loads cleanly with --web-limits.
2. Settle frame after motion (bug fix)
Reported regression: after orbiting, sub-pixel instances dropped by
motion-mode contribution culling stayed missing after the camera
stopped. Event-driven rendering means no frame is scheduled after
mouse-up, so the cull never re-ran at the still threshold.
Fix: track last_cull_was_motion_. If this frame used the motion
threshold, requestUpdate() after present to schedule one settle
frame. Next frame: camera_moved = false → still threshold → small
instances reappear. Matches GL's last_cull_was_motion_ behaviour.
Verified pixel-identical on basic.ifc; loads the user's dense scene
successfully under --web-limits (chunks=2 on the 139 MB model,
chunks=1 on the others).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the other half of task #10. The wgpu minimal already wrote PNGs
via wgpuCommandEncoderCopyTextureToBuffer + mapAsync; the GL backend
now has the equivalent via glReadPixels on the back buffer just before
swapBuffers.
- ViewportWindow::captureNextFrameToPng(path, quit_after=true) queues
a one-shot capture. render() reads the default framebuffer at full
pixel size (width * devicePixelRatio), flips bottom-up → top-down
into a QImage::Format_RGBA8888, saves PNG, and optionally
QCoreApplication::quit. Synchronous glReadPixels is fine here —
pick is interactive and rare; not used per-frame.
- ifcviewer-minimal --screenshot PATH wires through MinimalWindow
just like --camera / --benchmark. Honoured after all loads complete
(applyPendingBenchmark also drains pending_screenshot_).
Lets a parity script do:
IfcViewerMinimal foo.ifc --camera A,B,C,D,E,F --screenshot gl.png
IfcViewerWgpuMinimal foo.ifcview --camera A,B,C,D,E,F --screenshot wgpu.png
# then pixel-diff with whatever (ImageMagick, PIL, etc.)
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the interactive selection loop. After this commit you can:
- LMB-click an object → highlight (selection)
- Press H → hide all selected
- Press Shift+H → show all (clear hidden set)
- Press I → isolate selected (hide everything else)
WgpuVisibilityState (new header) is a plain unordered_set<uint32_t> of
hidden object_ids — mirrors src/ifcviewer/Visibility.h's shape but
stays Qt-free for the ifcviewer-core extract later.
cullModelCpuCompute consults visibility_.isHidden(inst.object_id)
before the frustum test — hidden instances cost nothing on every axis
(no draw, no depth contribution, no pick hit). The CPU vector is
read concurrently by the parallel cull workers, which is safe because
mutations only happen between renders (handlers requestUpdate after
mutating; render reads).
Hiding deselects (matches GL behaviour: H clears the now-invisible
selection rather than leaving phantom selected-but-invisible ids).
Stage 5's last piece — clip planes — is deferred. Adding the uniform
array + WGSL discard is mechanical, but the section-tool UI that
drives them isn't ported yet (minimal viewer has no way to place a
clip plane), so it'd ship as empty plumbing. Will land alongside the
section-tool port.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the loop on stage 4 (pick): clicking an object now highlights it
on screen. Plus the prerequisite plumbing for selection to behave
correctly across multi-sidecar loads.
Pieces:
1. WgpuSelectionState (new header)
CPU-side multi-set + active-id, mirroring the GL Selection.h shape
but pure stdlib (no Qt deps) so it can move into ifcviewer-core
later without dragging Qt across. clear/replace/add/remove/toggle
APIs + a fillFlagsArray helper that packs (selected, active) into
a u32 bitmap indexed by object_id.
2. selection_flags storage buffer + frame_bgl bump to 2 entries
Indexed by object_id, bit 0 = selected, bit 1 = active. Lives in
the frame bind group (group=0 binding=1) because object_ids are
globally unique — making it model-scoped would be the wrong cut.
ensureSelectionFlagsBuffer grows geometrically (64 → 128 → … u32)
as new models push next_object_id_ up, rebuilds the frame bind
group when it does.
3. Global object_id rebase in applyCachedModel
Each sidecar's local ids start from 1 and collide across files;
pick was previously ambiguous on multi-model loads. We now add
next_object_id_ as a base offset, rewrite InstanceCpu.object_id
(CPU mirror stays consistent) + InstanceGpu.object_id (what pick
reads back), and bump next_object_id_ by the model's max + 1.
4. WGSL main fragment reads sel_flags
Vertex shader passes inst.object_id through to fragment as
@interpolate(flat). Fragment reads sel_flags[object_id], mixes
(0.2, 0.6, 1.0) at 0.45 for in-selection and (0.4, 0.8, 1.0) at
0.40 on top for active. Same constants as the GL main shader.
5. Mouse → selection
LMB-click-without-drag pick result feeds the selection:
no modifier → replace
Shift → add
Ctrl → remove (active migrates to another id in the set)
miss + no modifier → clear
uploadSelectionFlagsIfDirty repacks + writes the GPU bitmap at
the top of the next render(); no upload on still frames.
Pick pipeline is unchanged — it already outputs the per-instance
object_id, and that's what the selection storage indexes.
Visibility + clip planes are pending follow-ups in stage 5 (mostly
small, share the same buffer-lifecycle pattern). Edge silhouette
(stage 9 partial), --screenshot diff harness (stage 10 partial),
ifcviewer-core extract (stage 12), and web chunking (stage 13) all
still pending.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 4 of the wgpu port. LMB-click-without-drag now resolves the
object_id under the cursor by running a dedicated pick render and
copying back the single texel at the click position.
- Pick pipeline reuses the existing pipeline_layout_ (same bindings
as main: frame uniform at group=0, per-model storages at group=1).
Different vs / fs entry points (vs_pick / fs_pick) in the main
WGSL module — the vertex pulling logic is duplicated for now but
the bind group layout match means no pipeline_layout rebuild and
pickObjectAt can reuse the current frame's already-uploaded
visible_draws + per-model bind groups.
- Pick FBO: surface-sized R32UInt color attachment + Depth32Float
depth, both single-sample (no MSAA — pick needs exact texel
access). CopySrc on the color so we can copyTextureToBuffer the
1×1 click region. Recreated on surface resize.
- pickObjectAt: encodes a one-shot pick pass + a single texel copy
into a 256-byte staging buffer, submits, mapAsync, sync-spins
processEvents until ready. Synchronous wait is fine here — pick
runs on click, not per-frame, so a sub-ms stall is invisible.
- Mouse integration: existing LMB drag-orbit preserved. A 3-pixel
threshold promotes drag (set nav_dragged_); release without
dragging triggers pickObjectAt at the release coords (logical
Qt → physical pixels via devicePixelRatio). object_id is logged;
selection state to consume the id arrives with stage 5.
Object_id 0 means miss (clear value); the pick attachment is cleared
to 0 before each pass and the fragment writes the instance's
object_id, so any non-zero result is a real hit on a drawn instance.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
First piece of stage 9 — the dark outlines BonsaiViewer / the GL backend
draw at depth discontinuities. Ported the GL renderEdgePass algorithm
verbatim, including the three things my earlier attempt missed:
1. Linearise depth to view-space metres before the Laplacian. Raw
[0,1] clip-z is heavily non-linear so a fixed-threshold edge
detector only caught near-camera silhouettes. Now reverses the
wgpu z-remap (z * 2 - 1 back to GL NDC) then standard reverse-
perspective to view-z.
2. Threshold scales with depth: t = EDGE_THRESHOLD * c. A 4 mm gap
between two surfaces reads the same whether it's 0.5 m or 50 m
away from the camera.
3. Multiplicative blend (Dst, Zero) with fragment output of
vec3(1 - edge). Strictly darkens, never brightens. Matches GL's
(GL_DST_COLOR, GL_ZERO) blend.
Constants EDGE_SCALE=6.0 / EDGE_THRESHOLD=0.004 are GL's tuned values.
Camera near/far hard-coded to 0.1 / 10000 (the viewport defaults);
they'll move to a small uniform when AppSettings ports across.
Pipeline state: depth-attachment-less, sample count 1, blend on, no
cull. Reuses depth_texture_'s TextureBinding usage that HiZ added.
Render pass loads the resolved main-pass colour (LoadOp_Load) and
writes back through the multiplicative blend; encoded between the main
pass and the HiZ resolve so HiZ uses the same MSAA depth that produced
the edges. edge_bind_group_ rebuilds lazily when depth_view_ is
replaced (mirrors the HiZ bind group lifecycle).
Perf cost on the 10-sidecar / 380k-instance benchmark: 0.1 ms (11.5 →
11.6 ms). Fullscreen depth-laplacian is essentially free on this GPU.
Remaining stage 9 work: HUD/labels/lines/points overlay primitives,
which need the QPainter-→-texture path. Lower visual priority than
edges; handled in a follow-up.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the perf gap to the GL backend on real BIM benchmarks. On a 10-
sidecar / 380k-instance corpus at a fixed --camera the wgpu binary went
from 110.6 ms to 11.6 ms (vs GL's 23 ms — half the frame time, but
note GL is doing extra work the wgpu backend hasn't ported yet; see
the caveats list at the bottom). Bundled because the pieces interlock
and shipping any of them without the others reintroduces the same wall.
1. Cross-mesh vertex pulling (single mega-draw per model)
The previous one-drawIndexed-per-(mesh × LOD-bucket) loop was costing
~13ms on a 27k-mesh scene. CPU now emits a flat visible_draws[]
(16 B per visible (mesh,lod,instance)) plus a prefix_sums[] table.
WGSL binary-searches prefix_sums by @builtin(vertex_index) to find
the entry, then manually fetches the mesh-local index from a
storage-bound indices[] and pulls the packed 12 B vertex. No
setIndexBuffer; the shader reads everything from storage. Bind
group grew from 4 to 7 entries (vertices, meshes, instances,
indices, visible_draws, prefix_sums, per-model uniform) — well
under WebGPU's mandatory 8 storage / 12 uniform floor.
2. Async HiZ readback via ping-pong staging buffers
Sync wait via wgpuInstanceProcessEvents was costing ~37 ms on a
real scene (GPU drain). Two staging slots now ping-pong: frame N
kicks a non-blocking mapAsync on slot K, frame N+1's first action
is one processEvents drain. Pyramid is 1-2 frames stale — matches
the "slightly-stale depth, fine" pattern the GL backend already
documents. encodeHizResolve returns -1 (skip) if both slots are
in flight; cull keeps using the most recent pyramid.
3. Cull reorder: contribution before HiZ
HiZ projection is ~10× more expensive than the contribution
check, yet most contribution-survivors would be HiZ-rejected
anyway on dense scenes. Computing projected_px first lets
contribution short-circuit ~80% of HiZ tests with no rejection-
quality loss. Saved ~34 ms on the dense bench.
4. Motion-mode contribution threshold
AppSettings::motionMinPixelRadius parity. While the camera is
changing (orbit/pan/zoom/--benchmark sweep), drop instances
below 10 px instead of 2 px. Halves visible_objects during
motion with no perceived quality loss.
5. Parallel cull (std::async across models)
Per-model cullModelCpu split into Compute (CPU-only, thread-safe)
+ Upload (main-thread wgpu queue writes). std::async fan-outs the
compute across models; main-thread joins and uploads. Wall-clock
cull on the 10-model corpus drops from ~17 ms single-threaded to
~9 ms across cores.
6. --no-hiz CLI flag + per-phase benchmark timings
Benchmark now also prints "per-frame avg ms: cull=X
hiz_readback=Y" so future regressions can be attributed without
guesswork. --no-hiz toggles the master switch from the CLI.
Honest caveats — wgpu is currently faster mostly because GL is doing
work we haven't ported yet:
- Edge silhouette pass (stage 9) will add ~3-5 ms back to wgpu.
- GL's HiZ uses the BVH so it rejects whole subtrees (1.7k vs
our 358 rejects on the same scene). BVH for HiZ is future work
(task #13 / a new task) — until then we draw more sub-pixel
geometry that's behind closer surfaces. Visually correct, perf
cost paid. Stage 4+5 are unaffected.
Verified pixel-identical on basic.ifc through every change. Real-scene
visual diff against GL pending the --screenshot flag on the GL minimal
(task #10's other half).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 7 of the wgpu port. Per-frame after the main render pass:
1. encodeHizResolve runs a depth-only render pass that samples the
MSAA depth texture (sample 0) and max-reduces it into a small
single-sample Depth32Float target (256 × ~h-aspect). Implemented
as a fullscreen-triangle WGSL pipeline; one nested loop per
output texel over its source rect. WebGPU has no built-in depth
resolve, so this combined resolve+downsample fragment shader is
the way.
2. copyTextureToBuffer writes the small resolved depth into a
CPU-mappable staging buffer (≈ 160 KB at 256×160).
3. readbackAndBuildHizPyramid maps the staging buffer (sync via
wgpuInstanceProcessEvents — small enough that the stall is
well under a millisecond), strips per-row padding, and CPU
max-reduces a full mip pyramid (level 0 → 1×1). Stores the VP
used so the next frame can project AABBs into the same space.
Next frame, cullModelCpu calls aabbOccludedByHiz after the frustum
test: projects all 8 AABB corners through hiz_vp_, computes the
screen-space AABB and the nearest projected z, picks the mip level
where the AABB covers ≤ 2 texels per axis, samples that level's 2×2
window, and culls iff min_z > max_pyramid_depth in [0,1] z.
Plumbing changes:
- depth_texture_ gains TextureBinding usage so the resolve shader
can read it.
- hiz_enabled_ master switch defaults true; mirrors IFC_NO_HIZ in
the GL backend. Disabling skips encode + readback entirely.
- Bench output's "hiz_rej N" field now reflects actual rejections.
Verified: basic.ifc (3 instances, no occluders) renders pixel-
identical to pre-HiZ — proves the test rejects nothing it shouldn't.
Real rejection counts need a dense scene; this should drop visible-
objects count noticeably on real BIM benchmarks where back-of-room
walls hide each other.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Quick win before the proper HiZ stage. Adds a min_pixel_radius
threshold (defaults 2.0 to match AppSettings::minPixelRadius() in GL):
instances whose projected bounding-sphere radius falls below it are
dropped from the per-mesh buckets entirely.
The projected_px math (radius_world * focal_px / view_z) is now
computed once per instance and shared with the LOD pick that uses the
same number. Saves one square root per instance per frame on dense
scenes vs the previous code path that only computed it inside the LOD
branch.
Expected impact on real BIM benchmarks: visible-objects count drops by
roughly 10×, matching the GL backend's number. Without this fix, wgpu
was drawing every frustum-surviving sub-pixel instance — most of the
work and most of the geometry the GL backend wasn't even submitting.
Motion-mode threshold bump (10.0 in GL during camera drag) lands
later when mouse-driven motion tracking is wired up.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Two pieces that block proper side-by-side parity with the GL minimal:
1. --camera tx,ty,tz,dist,yaw,pitch. Same format string as the GL
minimal so a pasted camera arg lands the same view on both backends.
setCamera() also flips initial_view_applied_ = true so the auto-
viewAll-on-first-load doesn't snap away from the script-set position
when the model finishes uploading.
2. Real BIM models exceed the conservative WebGPU defaults at device
create time. A 114k-instance / 19M-index sidecar's vertex storage is
139 MB, which trips wgpu's default 128 MB max_storage_buffer_binding_
size and bind-group creation fails. Now wgpuAdapterGetLimits is
called first and the device is requested at the adapter's full
ceiling — every desktop driver supports multi-GB.
Trade-off worth flagging: web parity will fail here because browsers
cap at the defaults. The eventual fix is to split a model's vertex/
instance storage into ≤128 MB chunks with a small per-frame routing
table, which is a real chunk of work. For now this unblocks all the
native benchmarking the user is actually doing.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Reported regression: --benchmark on the same sidecar visibly rotated
around a different point in the wgpu binary than in IfcViewerMinimal.
Root cause was two camera-convention drifts:
1. orbitEye placed the camera at (sin yaw, -cos yaw) from target;
the GL backend uses (cos yaw, sin yaw). Same target, but the
camera faces a different side of the model at yaw=0, which made
the orbit feel like it pivoted around a different point even
though the actual world-space target was the same. Now exactly
matches GL ViewportWindow::updateCamera:
eye.x = target.x + dist * cos(pitch) * cos(yaw)
eye.y = target.y + dist * cos(pitch) * sin(yaw)
eye.z = target.z + dist * sin(pitch)
2. viewAll's distance was an ad-hoc 0.6 * diag / tan(half_fov);
GL uses frameAabb(mn, mx, 1.10): tan_half = tan(fov/2),
min_aspect = min(aspect, 1), distance = (radius / (tan_half *
min_aspect)) * 1.10. Aspect-aware so portrait windows pull back
enough that the bounding sphere still fits on the tighter axis.
Now ported verbatim.
Also logs the computed target + distance on viewAll so a follow-up
side-by-side run prints both backends' framings and any remaining
discrepancy is easy to spot.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 8 of the wgpu port. cullModelCpu now buckets each visible instance
by (mesh_id, lod) instead of (mesh_id), and emits one MeshDraw record
per non-empty bucket. LOD pick projects the instance's world-space
bounding sphere to pixels via
projected_px = world_radius * focal_px / view_z
where focal_px = viewport_h / (2 * tan(fov_y/2)) and view_z is the
forward·(center-eye) depth. When projected_px < lod1_pixel_threshold_
AND the mesh has a baked LOD1 slice (MeshInfo.lod1_index_count > 0),
the instance draws the LOD1 index range instead of LOD0; baseVertex
and the vertex storage are shared between LODs.
mesh_draws can now grow to up to 2 × meshes.size() per frame (LOD0 + LOD1
slice per mesh). The visible_buffer layout per mesh becomes
[LOD0 instances | LOD1 instances] contiguous, with each MeshDraw
referencing its own firstInstance offset.
lod1_pixel_threshold_ defaults to 30 (mirrors AppSettings::
lod1PixelThreshold() in the GL backend); set to 0 to disable LOD1
entirely (always LOD0). AppSettings port lands in a later commit.
Verified: basic.ifc (3 tiny instances, no LOD1 baked by meshoptimizer
since each mesh is well under the 500-tri threshold) renders pixel-
identical to pre-stage-8 — proves the all-LOD0 path is preserved.
Real LOD switching needs a sidecar where buildLods produced LOD1 slices.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Closes the visible gap to BonsaiViewer down to just the post-process
edge silhouette pass (still pending in task #9). Four changes bundled
because together they bring up the parity story:
- WGSL fragment now applies cavity = clamp(length(fwidth(n))*1.5,
0, 0.35) and multiplies by (1 - cavity). Matches GL shader.
- Lighting constants switched to GL's exact values: key (0.3, 0.5,
0.8), fill (-0.3, -0.5, 0.8), sky tint (0.55, 0.60, 0.70), ground
tint (0.35, 0.32, 0.28). My initial guesses were close but not
identical; matching them means side-by-side diffs only flag actual
pipeline differences, not lighting tweaks.
- 4× MSAA: render pass writes into a MULTISAMPLE color attachment
(surface_format_-matched), resolves into the surface texture for
present. Depth is also 4 samples. Pipeline.multisample.count = 4.
ensureMsaaColorTexture / releaseMsaaColorTexture mirror the depth-
texture lifecycle. Matches GL minimal's QSurfaceFormat::setSamples(4).
- sRGB output fix. wgpu-native's Vulkan swap chain on X11 treats
BGRA8Unorm as sRGB-output (applies linear→sRGB encoding on shader
writes), even though caps.formats[0] reports plain Unorm. The GL
backend writes to a non-sRGB framebuffer with no such conversion,
so a clearValue of (0.125, 0.137, 0.161) lands as bytes (32, 35,
41) on GL but (99, 104, 112) on wgpu — ~3× brighter. Pre-decoding
via srgbToLinear on (a) the clearValue in C++ and (b) the final
fragment colour in WGSL makes wgpu's implicit encode round-trip,
so the final bytes match GL. Verified via screenshot pixel sample:
#202329 background reads as exactly (32, 35, 41).
Remaining visible gap to BonsaiViewer is the dark-line edge silhouettes
(renderEdgePass in GL, depth laplacian → outline). That belongs with
the overlay / post-process work in task #9.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Drag-down was decreasing pitch (camera diving), opposite to the GL
viewport's convention where drag-down increases pitch so the top of
the object rotates toward the viewer. Yaw direction was already
correct. Matches the existing user muscle memory from IfcViewerMinimal.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
The single "(file missing, wrong magic, or schema mismatch)" message
was making triage harder than necessary. loadSidecar now expands a
leading ~/ (shells skip it inside double quotes, which trips up paste-
from-launcher), and on failure peeks the file's header itself to
report exactly which check failed:
- "Sidecar not found" — file doesn't exist
- "Sidecar unreadable" — exists but open failed
- "Sidecar truncated" — <12 bytes
- "Sidecar magic mismatch" — wrong magic, reports got vs expected
- "Sidecar schema mismatch" — wrong version, reports both numbers
and suggests re-baking
- "Sidecar endianness mismatch" — cross-platform load attempt
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 11 of the wgpu port. WgpuViewportWindow gains setBenchmarkFrames(N);
the minimal driver wires it to a --benchmark N flag. Renders N frames
after a 5-frame warmup, yaw-sweeping the camera at 0.5°/frame, captures
per-frame wall time with QElapsedTimer (cull + encode + present), and
prints avg/median/p1/p99 + last-frame stats in the same line format as
IfcViewerMinimal so a script can diff them line for line.
Per-frame stats (visible_objects, visible_triangles, sub_draws) are now
summed in render() from m.mesh_draws. hiz_rej reports 0 until stage 7
adds HiZ occlusion.
Verified on basic.ifc (3 instances): wgpu 11.68 ms avg vs GL 11.75 ms
avg — same scene, same camera sweep, same window size. Noise-level
delta as expected on a tiny scene; the interesting comparison is on
real BIM corpora once you bake them to v13 sidecars.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
LMB drag → orbit (yaw/pitch, pitch clamped to ±89.9° to avoid gimbal
flip at the poles). MMB drag → pan in the camera's screen-space plane,
world-units-per-pixel sized against the view frustum at the pivot depth
so panning feels constant regardless of zoom. Wheel → zoom (12% per
notch, sign matches "wheel up = closer"). LMB is bound to orbit because
selection isn't wired yet; will rebind to selection + nav preset once
AppSettings ports over.
Pure addition to WgpuViewportWindow — overrides four QWindow event
handlers, no changes to render or cull paths. Lets you actually fly
around a loaded sidecar without a screenshot loop.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 6 of the wgpu port. Replaces the one-draw-per-(mesh, instance) loop
with a CPU cull pass that survives one drawIndexed per non-empty mesh
with packed instanceCount.
Adds to WgpuModelGpuData:
- visible_buffer: u32[] storage SSBO, pre-sized to instance_count at
applyCachedModel so the bind group reference never invalidates.
Re-uploaded each frame via wgpuQueueWriteBuffer.
- mesh_draws: per-mesh schedule (first_instance, instance_count,
first_index, base_vertex, index_count). instance_count==0 means the
mesh contributed nothing this frame and the draw is elided entirely.
cullModelCpu per-frame:
- Extract 6 frustum planes from the same VP we write into the uniform.
WebGPU clip-space z is [0, 1], so near plane = matrix row 2 (not
row 3 + row 2 as in GL); rest of the derivation is standard.
- Per-instance AABB-vs-frustum test using the p-vertex shortcut
(cheapest correct early-out for AABBs).
- Bucket survivors by mesh_id; flatten into a contiguous u32 list;
upload via wgpuQueueWriteBuffer. Per-mesh slice is [first_instance,
first_instance + instance_count).
WGSL adds @group(1) @binding(3) var<storage, read> visible: array<u32>
and an extra indirection: instance_idx = visible[iid]; the rest of the
shader is unchanged. firstInstance on each drawIndexed offsets into
visible[], so each mesh reads its own slice.
Verified two ways:
1. basic.ifc (3 instances, all on-screen) renders pixel-identically
to pre-stage-6 — proves cull keeps everything it should.
2. basic.ifc + a synthetic instance placed at (100, 100, 100) is
culled cleanly: only the cube renders, the far quad is rejected
by the frustum test. Proves cull actually rejects out-of-frustum
geometry rather than passing everything through.
Contribution culling, HiZ, and LOD selection arrive in stages 7 and 8;
they all hook into the same cullModelCpu seam.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Pulls the capture half of task #10 forward so we stop flying blind from
stage 3 onward. WgpuViewportWindow gains captureNextFrameToPng(path);
the minimal driver wires it to a --screenshot PATH flag that renders
one frame, copies the surface texture back to host memory, writes a
PNG via QImage, and quits.
CopySrc is added to the surface configuration usage so the surface
texture can be the copy source. The texel-to-buffer copy honours
WebGPU's 256-byte bytes-per-row alignment by padding rows and stripping
the padding when assembling the QImage. Surface format 28 (BGRA8Unorm)
is byte-swapped to RGBA on the way into QImage::Format_RGBA8888;
RGBA8 surface formats are memcpy'd straight through.
Verified end-to-end on /tmp/basic.ifcview: 3 cube meshes/instances
render with depth, back-face cull, and the hemisphere-ambient + key+fill
lighting model — top face reads sky (bright), front faces read mid-tone,
exactly as the WGSL shading intended. The pixel-diff half of task #10
(comparing against a GL baseline) lands later when the GL minimal binary
gets an equivalent flag.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 3 of the wgpu port. Replaces the clear-only render loop with the
full main shading pass:
- WGSL port of the GL main shader. Vertex-pulling: the vertex storage
buffer is read as array<u32> in the shader, with pos/normal/color
decoded manually per vertex. baseVertex (set per draw to mesh's
vertex offset) folds into @builtin(vertex_index) automatically;
firstInstance carries the instance slot for @builtin(instance_index).
No vertex-input layout — vertex pulling means no IA bindings.
- Render pipeline bound to depth-32-float (write-on, less compare),
back-face cull, CCW front face. Pre-multiplies a [-1,1]→[0,1] z-remap
matrix onto Qt's projection so WebGPU's clip-z convention is met.
- Two bind groups: group=0 per-frame (uniform with view-proj + key/fill
light + hemisphere ambient), group=1 per-model (three read-only
storage buffers: vertices, mesh quant, instances).
- Depth texture is created lazily and recreated on surface resize.
- Orbit camera state on WgpuViewportWindow with viewAll() that frames
the union of all loaded models' world AABBs after the first load.
Mouse navigation lands later.
- Draw loop: one drawIndexed per (mesh, instance) pair per model. This
is correct but CPU-heavy on dense scenes; stage 6 introduces the cull
+ compacted visible list that lets multiple instances of one mesh
collapse to a single call, and the eventual GPU-driven cull (post
sunset of the GL backend) goes further.
Verified on /tmp/quad_v13.ifcview (1 mesh, 1 instance) and on a real v13
sidecar baked from basic.ifc via the GL minimal viewer (3 meshes,
3 instances, 864 B verts). No wgpu validation errors fire across pipeline
creation, depth attachment, bind groups, or the draw loop on either.
Visual confirmation deferred until --screenshot lands (task #10) which
is being pulled forward next so we don't keep flying blind.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Stage 2 of the wgpu port. WgpuViewportWindow gains a queueLoadSidecar
API (called from the minimal driver before init) and an applyCachedModel
that runs after init: reads via SidecarCache::readSidecar, allocates
four wgpu buffers per model (vertex storage, index, mesh-quant storage,
instance storage), uploads via wgpuQueueWriteBuffer, retains a CPU
mirror of the MeshInfo/InstanceCpu arrays for the cull and picking
paths that arrive in later stages.
MeshGpu (the per-mesh quantization basis) is derived from MeshInfo on
the fly; InstanceGpu (transform + ids) is derived from InstanceCpu and
uses the cached float transform — composing from placement_transformation
against federation-stage matrices lands when stage 5 wires those.
SidecarCache.cpp is compiled into IfcViewerWgpu directly: it's pure
C++ with no Qt/OCCT/IFC-parse deps, so dragging in the IfcViewer
static lib for one source file would be wasteful. This duplication
goes away once src/ifcviewer-core/ is extracted (task #12).
Verified on a synthesised v13 sidecar (4 verts, 6 indices, 1 mesh,
1 instance) and a multi-sidecar load that assigns successive model_ids.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Adds src/ifcviewer-wgpu/ and src/ifcviewer-wgpu-minimal/ behind a new
BUILD_BONSAIVIEWER_WGPU option (default OFF), gated independently of
BUILD_BONSAIVIEWER. Stage 1 brings up a Qt window with a wgpu-native
v29 surface (X11) and clears to the background colour — no rendering
beyond that yet. Mirrors the lifecycle of the GL ViewportWindow so
subsequent stages (vertex-pulling renderer, pick, cull, HiZ, overlay)
slot in without restructuring the host.
wgpu-native is fetched as a pre-built binary release via FetchContent;
its .so SONAME is patched in at configure time so dependents get a
clean DT_NEEDED. The X11 native handle is obtained via the public
QNativeInterface::QX11Application API; Wayland and macOS/Windows
surface creation are stubbed with explicit "not wired yet" warnings.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Use Qt's system fixed font for viewer overlay text instead of the generic monospace family, avoiding the Windows font-resolution delay seen during measurement overlays.
Generated with the assistance of an AI coding tool.
Build the PyInstaller Autodesk connector without UPX compression. UPX-packed launchers are more likely to trigger enterprise Windows security scanning, and the connector is distributed as a fresh unsigned artifact for each build.
Generated with the assistance of an AI coding tool.
Update the overlay renderer's dynamic VBO uploads to bind the buffer and use glBufferData/glBufferSubData instead of direct-state glNamedBufferData/glNamedBufferSubData.
This avoids Windows/NVIDIA driver corruption seen with overlay axes, pick markers, HUD rects, and marquee rectangles while keeping the same overlay geometry and draw paths.
Generated with the assistance of an AI coding tool.
Build Rocky artifacts with shared IfcOpenShell libraries and keep geometry writer plugins out of executable packages while preserving them for Python packages.
Generated with the assistance of an AI coding tool.
The progress dialog was the only connector window not driven by a Tk
event loop: the handler created it, then blocked inline in httpx I/O.
On Windows CTkToplevel withdraws itself at construction and re-shows via
a delayed after() callback, which never fires without a running loop, so
the progress window stayed invisible for the whole transfer.
Add run_with_progress(): the blocking work runs on a daemon thread while
the main thread pumps the Tk loop and shows the dialog. Progress reports
are coalesced and marshalled back to the UI thread via _ProgressBridge,
and worker exceptions are re-raised on the main thread, preserving the
JSON-RPC error path. All eight upload/download handlers converted.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
test_instanced_geometry previously re-implemented vertex quantization
inline, with a stale comment claiming the helpers still lived in
ViewportWindow.cpp. They now live in VertexQuantization.h, so route the
test through the real quantizeVertex/octEncodeNormal and add coverage
for the degenerate-axis path, octahedral normal round-trip, the i8
normal error bound (~0.78 deg worst observed), and color passthrough.
Add test_visibility and test_selection: Tier-1 coverage of the two
per-object viewport state machines. Both are QObjects for their
changed() signal but touch no GL on the construction/mutation path, so
the tests exercise the pure CPU logic without a context.
Suite goes from 39 to 61 cases.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Introduce pytest coverage for the previously untested connector — rpc,
cache, settings, autodesk (auth + APS client) and connector handlers —
94 tests, runnable via the new `test` optional-dependency extra.
To make HTTP, time and the OAuth redirect testable without a network or
real sockets, add dependency-injection seams to autodesk.py:
AuthSessionService and ApsClient accept an optional httpx transport;
AuthSessionService accepts an injectable clock and callback_waiter; and
_wait_for_callback is extracted to the module-level wait_for_oauth_callback.
All seams default to the previous behaviour.
Remove the APS_CLIENT_ID environment-variable override: the client id now
comes solely from settings.json, collapsing settings.load_client_id and
simplifying the settings dialog.
CI: the build-bonsaiviewer-autodesk workflow gains a `test` job
(Python 3.11 + 3.13) that gates the build matrix.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Compile the Bonsai Viewer as part of the Linux and Windows binary builds,
and ship the Autodesk connector alongside the viewer executable.
Qt6 dependencies:
- The viewer links Qt6::Svg for runtime icon tinting. Svg is a separate
base-Qt archive, so aqt now installs "qtbase qtsvg" (plus icu on Linux)
rather than qtbase alone, on both Linux and Windows.
- Qt6::CorePrivate is exposed differently across Qt versions: Qt 6.8 ships
the target inside Qt6Core, while Qt 6.10 provides it only as a separate
CorePrivate config package. The viewer CMakeLists requests it via
OPTIONAL_COMPONENTS so it resolves on both.
- When cross-compiling Windows ARM64, windeployqt runs from the host x64
Qt, so qtsvg is installed into the host Qt as well.
Windows build:
- build-all-win.py passed -DBUILD_IFCVIEWER, a flag since renamed to
BUILD_BONSAIVIEWER, so the Windows build compiled no viewer at all. It
now passes -DBUILD_BONSAIVIEWER.
- The Autodesk connector is bundled under connectors/ next to
BonsaiViewer.exe in the packaged archive, mirroring the Linux builds.
- The Windows workflow builds the connector (PyInstaller) before the main
build so it is available to bundle.
Connector bundling:
- The Linux rocky workflows build the connector and bundle it into the
BonsaiViewer archive; the Windows build now does the same.
Generated with the assistance of an AI coding tool.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Connector discovery scanned a per-user data directory
(QStandardPaths::GenericDataLocation -> ~/.local/share/IfcOpenShell/
BonsaiViewer/connectors and the macOS/Windows equivalents). Connectors
are now meant to ship with the application, so there is no reason to
look outside the install tree.
Replace userConnectorsDir() with bundledConnectorsDir(), which returns
QCoreApplication::applicationDirPath() + "/connectors". discoverConnectors()
scans only that path; its first-wins / malformed-manifest handling is
unchanged.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Models panel: replace the manual resizeEvent column-sizing hack with
QHeaderView Stretch/Fixed modes, re-applied via sectionCountChanged so
they survive the model rebuilds that QHeaderView resets them on.
Dialog: only wrap the body in a QScrollArea when scrollable, mirroring
Panel. The scroll area caps its sizeHint at 36x24 cells, which turned
wide fixed-size dialog content into spurious scrollbars.
Add Model dialog: reserve a stable, font-metrics-measured height for the
hover description so longer text never reflows the buttons; regroup the
buttons into LOCAL / CLOUD / TOOLS.
Buttons: move the trailing-separator decision out of makeButtonGroup
into a new addButtonGroups row builder, so the last group in a row
never draws a dangling divider.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Loading a federated project (.ifcfed) with several models segfaults
non-deterministically on a fresh start. The viewer's SceneLoader spawns
one background std::thread per model in startDataSourceLoad() to
construct an ifcopenshell::file; with cached sidecars all models reach
that point near-simultaneously, so multiple threads parse different IFC
files at once. Parsing touches the process-wide schema singleton, which
was not thread-safe in two places.
Race 1 — concurrent schema population
-------------------------------------
schema_registry::get() lazily runs the schema's get_() function (e.g.
Ifc4::get_schema() -> IFC4_populate_schema()) and mutates entries_ with
no lock. Two threads calling schema_by_name("IFC4") at once both run
IFC4_populate_schema() concurrently, which fills global arrays
(IFC4_types[], strings[]). One thread reads a slot the other is still
writing.
Core-dump evidence (gdb thread apply all bt):
Thread 1 SIGSEGV in IFC4_populate_schema Ifc4-schema.cpp:1989
<- Ifc4::get_schema
<- schema_registry::get schema.cpp:241
<- schema_by_name("IFC4")
<- ifcopenshell::file::file (NWCH-PIR-SS...ifc)
<- SceneLoader::startDataSourceLoad lambda SceneLoader.cpp:315
Thread 3 also in IFC4_populate_schema (entity ctor for
"IfcMaterialProfileSetUsageTapering")
<- Ifc4::get_schema
<- schema_registry::get schema.cpp:241
<- ifcopenshell::file::file (NWCH-PIR-PT...ifc)
<- SceneLoader::startDataSourceLoad lambda
Two threads inside IFC4_populate_schema() at the same time is the race.
Fix: guard schema_registry's bind()/get()/names()/clear() with a
recursive_mutex (recursive because get() re-enters bind() via
load_schema_plugin(), and a freshly populated schema registers itself
through register_schema()). get() is serialized, so only the first
thread populates the schema; the rest block briefly and then observe
the finished result. Returned schema pointers are stable for the
process lifetime, so holding the lock only across get() is sufficient.
Race 2 — lazy all_attributes_ cache filled during parsing
---------------------------------------------------------
entity::all_attributes() lazily fills a `mutable` optional cache on the
shared schema entity the first time it is accessed — and that first
access happens during parsing (parse_context::construct), not during
schema population. With race 1 fixed, two parser threads still raced
here: both saw the cache empty, both did all_attributes_.emplace() and
std::copy() into it, corrupting the vector.
Core-dump evidence after the race-1 fix:
Thread 1 SIGSEGV in attribute::type_of_attribute (this=0xe130...55c)
<- std::transform(first=0x4, last=0xb0d1...) <-- garbage
iterators into a corrupt std::vector
<- parse_context::construct over
decl->as_entity()->all_attributes() file.cpp:249
<- instance_streamer::read_instance
<- ifcopenshell::file::file (NWCH-PIR-PT...ifc)
<- SceneLoader::startDataSourceLoad lambda
The begin pointer 0x4 is a half-written vector being read mid-resize by
another thread.
Fix: force every entity's all_attributes_ cache in the
schema_definition constructor, while construction is still
single-threaded. The schema is then genuinely immutable after
construction, so concurrent parsing needs no hot-path lock.
Both crashes reproduce reliably on a fresh start at native speed but
vanish under gdb (which serializes thread scheduling) — the classic
signature of a data race. With both fixes the federated load completes
cleanly.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Create a standalone Sphinx docs tree for Bonsai Viewer and migrate the Autodesk connector Markdown documentation into RST.\n\nGenerated with the assistance of an AI coding tool.
Replace the old IFC viewer build switch with BUILD_BONSAIVIEWER in CMake, the Linux workflows, and the nix build script.
Generated with the assistance of an AI coding tool.
Replace the "Open Recent coming soon" placeholder with a working
most-recently-used project list. RecentProjects persists .ifcfed paths
via QSettings, capped and pruned to existing files. The Open Recent
ribbon button now shows a popup menu of recent projects; every
successful open or save (local or cloud) records an entry.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Sort hubs, projects, folders and files alphabetically. Allow
multi-select when adding models so several can be pulled at once.
Rework the progress dialog into a fixed-shape two-line layout that
shows percent and byte counts, middle-eliding long filenames so the
window never reflows.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Persist the OAuth callback port in connector settings, expose it in the settings dialog, and use it when constructing the localhost callback URL.
Generated with the assistance of an AI coding tool.
Rename the user-facing serialisers page to formats and document .rdbview as a Bonsai Viewer package.\n\nGenerated with the assistance of an AI coding tool.
Follows the host viewer's rename to Bonsai Viewer: directory, Python
package, entry point, PyInstaller spec, keyring service, and on-disk
config/cache paths all use the bonsaiviewer-autodesk name. CI workflow
filename and path filters updated to match.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Directory src/ifcviewer-full -> src/bonsaiviewer, CMake target
IfcViewerFull -> BonsaiViewer, namespace ifcviewerfull -> bonsaiviewer,
QApplication / window titles / connector path now use the new brand.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Build the ifcviewer-autodesk connector bundle on push/PR/dispatch for the four supported targets: linux-x86_64 (ubuntu-22.04, oldest reasonable glibc), macos-arm64, macos-x86_64, and windows-x86_64. Each job runs packaging/build.py and uploads the resulting autodesk-<os>-<arch>.zip as an artifact.
Generated with the assistance of an AI coding tool.
Implements the viewer side of CLOUD_SYNC_PROTOCOL.md: connector
discovery, JSON-RPC stdio host, and Open/Save/Sync/Add cloud workflows
wired through the ribbon, Models panel right-click, and Settings tab.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Initial implementation of the ifcviewer-autodesk connector — a separate process that bridges the IfcViewer to Autodesk APS (BIM 360 / ACC). Speaks JSON-RPC 2.0 over stdio per CLOUD_SYNC_PROTOCOL.md (also added). PKCE OAuth with keyring-backed token storage, customtkinter browse/picker UI, and PyInstaller packaging.
Implements both interactive and non-interactive variants of each push/pull (pull_ifcfed[_interactive], pull_models[_interactive], push_ifcfed[_interactive], push_model[_interactive]) so the viewer can offer both "Save"/"Open from Cloud" and "Save As"/"Add Model from Cloud" entry points. File transfers report progress through a dialog with per-byte updates; pull_models shows "(i/N)" for batches.
Generated with the assistance of an AI coding tool.
Use IfcMapConversion.Scale as the source of truth for converting map coordinates to metres, instead of deriving that scale from IfcProjectedCRS.MapUnit. Bump the sidecar version because cached georef matrices and unit scales may differ under the new interpretation.
Generated with the assistance of an AI coding tool.
Keep placement transformations in double precision through streaming, sidecar caching, and viewport recomposition so large coordinates can be cancelled before the final GPU float upload.
Generated with the assistance of an AI coding tool.
Renamed HeadlessSidecarBuilder to SidecarBuilder and reused it for live
loads. SceneLoader now constructs one per stream load, forwards meshReady
/instanceReady chunks alongside the viewport upload, and finalizes +
writes the sidecar at onStreamerFinished — no more GPU readback path
via ViewportWindow::snapshotModel (removed). Same code path now produces
sidecars for both live loads and the .rdbview offline export.
Sidecar use is opt-in per direction via SceneLoader::setShouldReadSidecar
and setShouldWriteSidecar; both default off so embedders that don't want
caching get a pure-streaming loader. ifcviewer-full and ifcviewer-minimal
opt in.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Dion Moult