Models now resolve to global coordinates, which alone would make things worse:
composed per-instance transforms are float32, and around six million metres
that quantises at roughly half a metre. So the first model to load also sets a
false origin, derived from where its geometry actually sits, unless a host has
set one itself.
WebFederation owns the concepts an .ifcfed carries — a federation unit, a false
origin, a per-model transform and display name — without the file format. The
desktop Federation class is a document model whose sources are local filesystem
paths, which mean nothing in a browser; a host page that wants .ifcfed can parse
the JSON and drive these calls.
Models are keyed by the JS source id rather than the session model id. The
source id exists the moment a File or URL is registered, whereas the session id
is minted inside the async range-read chain, so keying on it lets a transform be
set before the model has streamed and applied when it arrives — the model never
visibly jumps. loadSidecarMetadataWeb gained a completion callback to carry that
id back out, and addFile/addUrl now return the source id and fire onModelLoaded,
where before they were fire-and-forget with no handle and no completion signal.
The embedded sample bypasses the source registry, so it is bound separately;
otherwise the guess never runs for a page that only ever shows the sample.
georef-a and georef-b are the regression fixture: two boxes whose different map
conversions resolve to the same real-world point, so a viewer that applies them
draws one box's worth of scene and one that ignores them spans 707 m. They carry
two meshes each because reorderSidecarByMorton bails out below two and then
writes no chunk table, and a sidecar without one cannot stream over byte ranges.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Give host pages a real API over the web viewer, not just "embed it and listen
for picks": read/set the camera, read/set multi-selection, enumerate every
object with its IFC identity, drive per-object visibility, and override
object colours.
The wasm boundary keeps to object_ids (u32 arrays marshalled through the heap,
with an "ask twice" convention on the getters); web/ifcviewer.js layers IFC
GlobalId resolution on top, from the element table getObjects() fetches. Every
id-taking call accepts an objectId, a GlobalId, or an element object.
Colour override needed no new mechanism: color_override_rgba8 was already
plumbed through the sidecar, the instance SSBO, the WGSL shader and the
opaque/transparent cull classifier, but nothing ever wrote a non-zero value
into it. setObjectsColor is the missing writer, which is why an alpha below 255
correctly reclassifies the instance into the transparent pass.
Two bugs surfaced while wiring this up:
- wgpu_initialized_ was only ever set by the Qt desktop host, so on web every
upload guarded on it was a silent no-op — including the pre-existing
recomposeAndUploadModel that federation transforms depend on. The core now
latches it in its own web init.
- The demo pages were copied into the build dir by a POST_BUILD command on the
wasm target, so they only refreshed when the wasm itself relinked; editing a
page left a stale copy that the dev server (and the Playwright suite) kept
serving. Each page now has its own copy rule with a real dependency, and
sample.ifcview is a LINK_DEPENDS so regenerating it forces a relink.
applyCachedModel also now keeps the element metadata it already parses on the
path-based load (it was being dropped), so the embedded sample has GUIDs and
the demo works with no file to pick.
The sample model was three coincident cubes, which made per-object hide and
colour look like no-ops — whatever you hid was still drawn by the box behind
it. make_sample.py regenerates it as a slab, a wall and a beam in distinct
places, so the fixture is reproducible rather than an opaque blob.
Demoed by web/scripting.html (linked from the index; viewer is on
window.viewer) and covered by tests/scripting.spec.mjs — 6 cases against a real
GPU, asserting visibility and colour at the pixels, not just at the API.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Dion Moult