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Dion Moult
0ec72482c2
Many Vulkan drivers cap a single VkDeviceMemory allocation at exactly
maxStorageBufferBindingSize (NVIDIA: 2 GB on consumer GeForce) or
refuse big contiguous allocations once heap is fragmented. The old
addSubBuffer gave up at the first refusal, latching growth_disabled_
— so on a 4 GB GeForce we extracted 2 GB and called it done.
The wgpu-mem-probe tool (feab05650) showed the driver actually grants
~3 GB total across multiple sub-buffers — invariant under allocation
pattern (2+1+small, 3×1 GB, 6×512 MB, 12×256 MB all land at 3 GB).
The cap is the hardware/desktop, not the request size.
addSubBuffer now starts at last_growth_size_ (initially
per_sub_buffer_capacity_, decays as the driver refuses larger sizes)
and halves on failure inside a single call. Stops at a 64 MB floor;
below that the per-sub-buffer bookkeeping cost (free list, bind
groups) isn't worth it. growth_disabled_ now latches only when even
64 MB is refused — a true hardware ceiling, not just "the first
attempt didn't fit."
pool_can_fit gains a next_growth_size_bytes() accessor to stay
honest about how big a future sub-buffer can be after the driver
has refused larger sizes.
Measured (big federation, --streaming, close camera):
pool capacity: 2048 MB → 2688 MB (2 GB + 512 MB + 128 MB)
VRAM resident: 2155 MB → 2800 MB (whole scene fits, no eviction)
avg fps: 42 → 53
stream time: 2.5 ms → 0.1 ms (no churn — working set is stable)
On larger GPUs (8 / 16 / 24 GB workstations) the same code extracts
proportionally more (e.g. 4 × 2 GB on a 10 GB+ card).
The GL backend's higher "4+ GB resident" claim is overcommit into
host RAM — explicit Vulkan/wgpu memory management deliberately
doesn't paper over that, and the wgpu-mem-probe data confirms it
isn't recoverable.
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* |