render() was re-running the full cull every 16 ms timer tick even when nothing had changed — the camera matrices, scene state, and therefore visible set were all identical to the previous frame's. The GPU was still happy to redraw from the cached indirect buffer, but the CPU was burning 21 ms/frame rebuilding the same visible list. Detect the no-op case by comparing view/proj against last_cull_view_ / last_cull_proj_ and checking a scene-dirty flag (have_cached_cull_) that every mutator on models_gpu_ invalidates — finalizeModel, applyCachedModel, applyLodExtension, hide/show/remove/reset, and uploadInstanceChunk. When the check passes we skip both cullAndUploadVisible and buildHizPyramid (the depth buffer is bit-identical, so re-reading it produces the same pyramid). Per-model visible_objects / visible_triangles stats now live on ModelGpuData so the stats line reports correct numbers on skipped frames instead of reading from a stale indirect_scratch_. Measured on a 569k-object overview: still frames go 22 fps → 62 fps; orbiting goes 23 fps → ~30-50 fps depending on how hard you move the mouse (the cull only pays its full cost on the ~25 % of frames where the camera actually moved). The stats line gains a "skipped N/M" field so you can see the ratio live. Co-Authored-By: Claude Opus 4.6 <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* |