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https://github.com/IfcOpenShell/IfcOpenShell.git
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Dion Moult
7dc13eb104
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>
IfcOpenShell
IfcOpenShell is an open source (LGPL) software library for working with Industry Foundation Classes (IFC). Complete parsing support is provided for IFC2x3 TC1, IFC4 Add2 TC1, IFC4x1, IFC4x2, and IFC4x3 Add2. Extensive geometric support is implemented for the IFC releases IFC2x3 TC1 and IFC4 Add2 TC1. Extending with support for arbitrary IFC schemas is possible at compile-time when using C++ and at run-time when using Python.
In addition to a C++ and Python API, IfcOpenShell comes with an ecosystem of tools, notably including IfcConvert (an application to convert IFC models to other formats), Bonsai (an add-on to Blender providing a graphical IFC authoring platform), and many other libraries, CLI apps, and more. Support is also provided for auxiliary standards such as BCF and IDS.
For more information, see:
Development is sponsored through your generous donations!
Contents
| Name | Description | License | Service |
|---|---|---|---|
| bcf | Library to read and write BCF-XML and query OpenCDE BCF-API modules | LGPL-3.0-or-later |   |
| bonsai | Add-on to Blender providing a graphical native IFC authoring platform | GPL-3.0-or-later |    |
| bsdd | Library to query the bSDD API | LGPL-3.0-or-later |  |
| ifc2ca | Utility to convert IFC structural analysis models to Code_Aster | LGPL-3.0-or-later | |
| ifc4d | Convert to and from IFC and project management software | LGPL-3.0-or-later |  |
| ifc5d | Report and optimise cost information from IFC | LGPL-3.0-or-later |  |
| ifcbimtester | Wrapper for Gherkin based unit testing for IFC models | LGPL-3.0-or-later | |
| ifcblender | Historic Blender IFC import add-on | LGPL-3.0-or-later* | |
| ifccityjson | Convert CityJSON to IFC | LGPL-3.0-or-later |  |
| ifcclash | Clash detection library and CLI app | LGPL-3.0-or-later |  |
| ifcconvert | CLI app to convert IFC to many other formats | LGPL-3.0-or-later* |   |
| ifccsv | Library and CLI app to export and import schedules from IFC | LGPL-3.0-or-later |  |
| ifcdiff | Compare changes between IFC models | LGPL-3.0-or-later |  |
| ifcedit | CLI wrapper for ifcopenshell.api IFC model mutation functions | LGPL-3.0-or-later |  |
| ifcfm | Extract IFC data for FM handover requirements | LGPL-3.0-or-later |  |
| ifcmax | Historic extension for IFC support in 3DS Max | LGPL-3.0-or-later* | |
| ifcmcp | MCP server for querying and editing IFC building models | LGPL-3.0-or-later |  |
| ifcopenshell-python | Python library for IFC manipulation | LGPL-3.0-or-later* |         |
| ifcpatch | Utility to run pre-packaged scripts to manipulate IFCs | LGPL-3.0-or-later |  |
| ifcquery | CLI tool for querying and inspecting IFC building models | LGPL-3.0-or-later |  |
| ifcsverchok | Blender Add-on for visual node programming with IFC | GPL-3.0-or-later |  |
| ifctester | Library, CLI and webapp for IDS model auditing | LGPL-3.0-or-later |  |
The IfcOpenShell C++ codebase is split into multiple interal libraries:
| Name | Description | License |
|---|---|---|
| ifcgeom | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcgeom_schema_agnostic | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcgeomserver | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcjni | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcparse | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| ifcwrap | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| qtviewer | Internal library for IfcOpenShell | LGPL-3.0-or-later* |
| serializers | Internal library for IfcOpenShell | LGPL-3.0-or-later* |