# ifc2xkt [![This project is using Percy.io for visual regression testing.](https://percy.io/static/images/percy-badge.svg)](https://percy.io/73524691/xeokit-ifc-to-xkt) [![npm version](https://badge.fury.io/js/%40xeokit%2Fxeokit-ifc-to-xkt.svg)](https://badge.fury.io/js/%40xeokit%2Fxeokit-ifc-to-xkt) ### An Experimental WASM-Based IFC Importer for xeokit [ifc2xkt](https://github.com/xeokit/xeokit-ifc-to-xkt) is an experimental CLI tool for Node.js that converts geometry from IFC files into [xeokit](https://xeokit.io)'s native XKT geometry format. The XKT format compresses huge double-precision models into a compact payload that can be rapidly loaded over the Web into a xeokit viewer. This experimental converter provides a one-step IFC→XKT conversion, using the experimental WASM-based [web-ifc](https://github.com/tomvandig/web-ifc) library to parse the IFC input, and [xeokit-xkt-utils](https://github.com/xeokit/xeokit-xkt-utils) to generate the XKT output. [![Schependomlaan](https://xeokit.github.io/xeokit-ifc-to-xkt/assets/rac_advanced_sample_project.png)](https://xeokit.github.io/xeokit-ifc-to-xkt/tests/loadXKT.html?xkt_src=models/xkt/rac_advanced_sample_project.xkt) * [[View this XKT model](https://xeokit.github.io/xeokit-ifc-to-xkt/tests/loadXKT.html?xkt_src=models/xkt/rac_advanced_sample_project.xkt)] # Contents - [Introduction](#introduction) - [Usage](#usage) - [Compatibility](#compatibility) - [Features](#features) - [Architecture](#architecture) - [Examples](#examples) + [Example 1: Basic Model](#example-1--basic-model) + [Example 2: Double Precision Geometry](#example-2--double-precision-geometry) - [Benchmarks](#benchmarks) + [Issues found in benchmarks](#issues-found-in-benchmarks) - [Visual Tests](#visual-tests) - [Acknowledgements](#acknowledgements) # Acknowledgements This project builds on previous work that was generously contributed to the community by open source BIM developers: * [web-ifc](https://github.com/tomvandig/web-ifc) created by [@tomvandig](https://github.com/tomvandig) * [web-ifc-viewer](https://github.com/agviegas/web-ifc-viewer) created by [@agviegas](https://github.com/agviegas) # Usage Clone the [repository](https://github.com/xeokit/xeokit-ifc-to-xkt) and install the converter. Note that we're using ````git lfs clone```` so that we get some example IFC files to convert. ```bash git lfs clone https://github.com/xeokit/xeokit-ifc-to-xkt.git cd xeokit-ifc-to-xkt npm install ``` Now you're ready to convert some IFC files. To convert a file, run ````ifc2xkt````, specifying paths to the source IFC file and the target XKT file. ```bash node ifc2xkt.js -s ./tests/models/ifc/Schependomlaan.ifc -o ./tests/models/xkt/Schependomlaan.xkt ``` Once you've got your XKT file, you can then view it with xeokit in the browser. ```bash import {Viewer, XKTLoaderPlugin} from "../dist/xeokit-sdk.es.js"; const viewer = new Viewer({ canvasId: "myCanvas" }); const xktLoader = new XKTLoaderPlugin(viewer); const model = xktLoader.load({ id: "myModel", src: "./tests/models/xkt/Schependomlaan.xkt" }); ``` # Compatibility XKT files generated by ````ifc2xkt```` work with [xeokit-sdk](https://github.com/xeokit/xeokit-sdk) versions 1.9 and later. # Features - Converts IFC 2x3 and 4 to XKT - Runs in Node.js - Fast conversion using WASM - Direct IFC→XKT conversion without intermediate file formats - Compact XKT output - Double-precision geometry, enabling models to be viewed at their original site placement # Architecture As mentioned, [ifc2xkt](https://github.com/xeokit/xeokit-ifc-to-xkt) is built around two open source libraries: * [web-ifc](https://github.com/tomvandig/web-ifc) - an MIT-licensed library from [@tomvandig](https://github.com/tomvandig), which loads an IFC file into an in-memory document model that represents the IFC geometry content. * [xeokit-xkt-utils](https://github.com/xeokit/xeokit-xkt-utils) - an AGPL3-licensed library from xeolabs that builds an in-memory XKT document model and saves it as an XKT file. Using these two libraries together, [ifc2xkt](https://github.com/xeokit/xeokit-ifc-to-xkt) performs the following steps: 1. loads an IFC into an in-memory IFC document model, 2. translates the IFC document model into an XKT document model, then 3. serializes the XKT document model to an XKT file. # Examples ### Example 1: Basic Model In this first example, we're converting an IFC 2x3 file to XKT. This model is centered at the IFC coordinate origin, and therefore relies on single-precision geometry. ```bash time node ifc2xkt.js -s Schependomlaan.ifc -o Schependomlaan.xkt Reading IFC file: ifc/Schependomlaan.ifc Wrote file Loading: ifc/Schependomlaan.ifc Read Loading Tape 44348356 Lines normal 714486 Max express ID 1080892 Loaded 714486 lines in 339 ms! Array buffer size: 1040.375 kB Writing XKT file: Schependomlaan.xkt real 0m3.562s user 0m4.752s sys 0m0.241s ``` [![Schependomlaan](https://xeokit.github.io/xeokit-ifc-to-xkt/assets/Schependomlaan.png)](https://xeokit.github.io/xeokit-ifc-to-xkt/tests/loadXKT.html?xkt_src=models/xkt/Schependomlaan.xkt) * [[View this XKT model](https://xeokit.github.io/xeokit-ifc-to-xkt/tests/loadXKT.html?xkt_src=models/xkt/Schependomlaan.xkt)] ### Example 2: Double Precision Geometry In this second example, we're converting an IFC 4 model which is placed at ````[1842022, 10, -5173301]````, and consequently relies on double-precision geometry coordinates, because the coordinate values will be huge. This model is of the Marc Antoine apartment building in Lyon, and was provided by BIMData.io. ```bash time node ifc2xkt.js -s MAP.ifc -o MAP.xkt Reading IFC file: ifc/MAP.ifc Wrote file Loading: ifc/MAP.ifc Read Loading Tape 23548265 Lines normal 475783 Max express ID 833829 Loaded 475783 lines in 208 ms! Array buffer size: 1342.054 kB Writing XKT file: MAP.xkt real 0m3.685s user 0m4.889s sys 0m0.173s ``` [![MAP](https://xeokit.github.io/xeokit-ifc-to-xkt/assets/MAP.png)](https://xeokit.github.io/xeokit-ifc-to-xkt/tests/loadXKT.html?xkt_src=models/xkt/MAP.xkt) * [[View this XKT model](https://xeokit.github.io/xeokit-ifc-to-xkt/tests/loadXKT.html?xkt_src=models/xkt/MAP.xkt)] # Benchmarks The table below shows benchmarks for ````ifc2xkt```` 0.0.1-alpha using various IFC2x3 and IFC4 files. Click "View" in the last column to open each benchmark's converted XKT file in a xeokit viewer.
Model IFC Size XKT Size Objects Meshes Conversion Time View
Holter Tower 169.12M 6.26M 121100 89546 46.37s View
Conference Center 71.70M 3.99M 12174 5323 9.5s View
Schependomlaan 49.28M 1.04M 7270 4761 3.5s View
rac_advanced_sample_project 43.22M 6.62M 11122 2870 10.75s View
rme_advanced_sample_project 33.67M 1.74M 12884 3897 11.32s View
MAP (double precision) 29.35M 1.3M 3548 3680 3.6s View
IfcOpenHouse2x3 0.11M 0.01M 80 18 0.28s View
IfcOpenHouse4 0.11M 0.01M 80 18 0.21s View
### Issues found in benchmarks - Holter Tower has missing objects - MAP has misaligned objects - Some colors are incorrect # Visual Tests We're using visual testing on Percy to catch bugs in ````ifc2xkt````. See the latest test reports here: [https://percy.io/73524691/xeokit-ifc-to-xkt](https://percy.io/73524691/xeokit-ifc-to-xkt) [![Percy](https://xeokit.github.io/xeokit-ifc-to-xkt/assets/percy.png)](https://percy.io/73524691/xeokit-ifc-to-xkt) # Further Work * Debug the transform precision loss in web-ifc. * Support point clouds, line segments * Somehow configure rollup.js to build a CJS binary that bundles ````web-ifc.wasm````.