conway-geom

conway-geom is Bldrs’ rewrite of web-ifc, engineered for high-performance and to support the full suite of open CAD standards within the IFC and STEP families. conway-geom is written in C++ & javascript and deployed as a WASM module, e.g. in Bldrs Share.

Features:

• Fast near-exact CSG: Our cutting-edge implementation of Constructive Solid Geometry (CSG) partly based on “Exact predicates, exact constructions and combinatorics for mesh CSG” Lévy et al. 2024 [https://arxiv.org/pdf/2405.12949], with robust handling of real-world model data, tailored for the web environment.
• Seamless NURBS and Advanced BREP: Conway ensures smooth handling of Non-Uniform Rational B-Splines (NURBS) and Advanced Boundary Representation (BREP), with adaptive tesselation preserving accuracy and quality across complex geometries to streamline workflows for intricate designs.
• Advanced Model Introspection: More than pretty pictures, Conway gives type-safe access and powerful querying including geometric relations.
• Enhanced Memory Handling: Enables smooth, lag-free interaction with large, highly detailed 3D models across devices, even with complex assets or high-poly designs.
• Web Geom: Common libraries shared with including Earcut, Manifold, csgjs-cpp, fast_float, GLM, and tinynurbs for robust, high-speed processing.

IFC Schema Coverage

Conway generates code bindings for the entire IFC 4.x specs, of 1000+ types. Around 10% of those types have geometric representations. conway-geom covers most of these (80% Nov 2024) and is progressing towards full coverage. See IFC_Coverage for a detailed coverage report.

Getting Started

1. Install EMSDK and follow the instructions for your platform.
2. Install the gmake and node dependencies via Homebrew (brew install gmake node).
3. Clone this repo and navigate to the root of the repository.

We've noticed some sentitivity in versions, so here's the most recent working ver:

emsdk % ./emsdk activate latest
Resolving SDK alias 'latest' to '3.1.48'
Resolving SDK version '3.1.48' to 'sdk-releases-694434b6d47c5f6eff2c8fbd9eeb016c977ae9dc-64bit'
Setting the following tools as active:
   node-16.20.0-64bit
   python-3.9.2-64bit
   releases-694434b6d47c5f6eff2c8fbd9eeb016c977ae9dc-64bit
emscripten % ./emcc -v
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.48 (e967e20b4727956a30592165a3c1cde5c67fa0a8)
clang version 18.0.0 (https://github.com/llvm/llvm-project a54545ba6514802178cf7cf1c1dd9f7efbf3cde7)
Target: wasm32-unknown-emscripten
Thread model: posix

Init Win

1. Install MinGW-64 and add g++.exe location to your PATH variable.

Build

These will genie and use gmake to build wasm modules (single and multithreaded) + native test executables in debug or release mode.

Build (Mac OS)

1. Add EMSDK environment variable to your terminal path. Example: . $EMSDK_DIR/emsdk_env.sh
2. Run git submodule update --init --recursive
3. cd dependencies/wasm ; unzip dependencies.zip ; cd -
4. Run build_osx.sh release (wasmNode|wasmWeb) profile or build_osx.sh release (wasmNode|wasmWeb)

Build (Windows)

1. Add EMSDK environment variable to your terminal path. Example: EMSDK=D:\emsdk (no trailing slash)
2. Add EMSCRIPTEN environment variable, example: EMSCRIPTEN=D:\emsdk\upstream\emscripten
3. Run git submodule update --init --recursive
4. Run build_win.bat release (wasmNode|wasmWeb) profile or build_win.bat release (wasmNode|wasmWeb)

conway_native Usage

1. Running application currently parses geometry from index.ifc and outputs individual obj files + a single complete obj file.

webifc_native Usage

1. Launching executable with no arguments loads index.ifc from repository root and parses ifc type information.
2. -i /Path/To/IFC.ifc - Loads external ifc files and parses ifc type information.
3. -objs - outputs geometry from ifc to individudal obj files
4. -stats - outputs currently supported ifc type coverage for a given ifc file
5. -statsv - Outputs currently supported ifc type coverage + prints type name info for a given ifc file
6. -t - Traces and prints IFC type information gathered from parsing a given ifc file
7. -c - Prints generated code for conway geometry processor (Internal only - used for debugging / development - WIP)
8. -h - Displays help.