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https://github.com/kovacsv/occt-import-js
The emscripten interface for OpenCascade import functionalities.
https://github.com/kovacsv/occt-import-js
3d brep brp iges igs import opencascade step stp
Last synced: 8 days ago
JSON representation
The emscripten interface for OpenCascade import functionalities.
- Host: GitHub
- URL: https://github.com/kovacsv/occt-import-js
- Owner: kovacsv
- License: lgpl-2.1
- Created: 2022-01-23T17:56:41.000Z (almost 3 years ago)
- Default Branch: main
- Last Pushed: 2024-09-03T15:52:09.000Z (2 months ago)
- Last Synced: 2024-10-12T22:16:31.974Z (26 days ago)
- Topics: 3d, brep, brp, iges, igs, import, opencascade, step, stp
- Language: C++
- Homepage:
- Size: 69.4 MB
- Stars: 154
- Watchers: 5
- Forks: 24
- Open Issues: 14
-
Metadata Files:
- Readme: README.md
- Funding: .github/FUNDING.yml
- License: LICENSE.md
Awesome Lists containing this project
README
# occt-import-js
The [emscripten](https://emscripten.org) interface for [OpenCascade](https://www.opencascade.com) import functionalities. It runs entirely in the browser, and allows you to import brep, step and iges files and access the result in JSON format.
[](https://badge.fury.io/js/occt-import-js)
[](https://github.com/kovacsv/occt-import-js/actions/workflows/wasm_build.yml)
[](https://github.com/kovacsv/occt-import-js/actions/workflows/native_build.yml)
See it in action in [Online 3D Viewer](https://3dviewer.net/#model=https://dl.dropbox.com/s/utieopxrxwujgmd/as1_pe_203.stp), or check [this fiddle](https://jsfiddle.net/kovacsv/rzhq9gxj) for a code example.
## How to install?
You can get occt-import-js from [npm](https://www.npmjs.com/package/occt-import-js):
```
npm install occt-import-js
```
## How to use?
The library runs in the browser and as a node.js module as well.
You will need two files from the `dist` folder: `occt-import-js.js` and `occt-import-js.wasm`. The wasm file is loaded runtime by the js file. There are three public functions in the library:
- `ReadBrepFile` to import brep file.
- `ReadStepFile` to import step file.
- `ReadIgesFile` to import iges file.
All functions have two parameters:
- `content`: The file content as a `Uint8Array` object.
- `params`: Triangulation parameters as an object, can be `null`.
- `linearUnit`: Defines the linear unit of the output. Possible values: `millimeter`, `centimeter`, `meter`, `inch`, `foot`. Default is `millimeter`. Has no effect on brep files.
- `linearDeflectionType`: Defines what the linear deflection value means. Default is `bounding_box_ratio`. Possible values:
- `bounding_box_ratio`: The `linearDeflection` value contains a ratio of the avarage bounding box.
- `absolute_value`: The `linearDeflection` value contains an absolute value in the unit defined by `linearUnit`.
- `linearDeflection`: The linear deflection value based on the value of the `linearDeflectionType` parameter.
- `angularDeflection`: The angular deflection value.
You can find more information about deflection values [here](https://dev.opencascade.org/doc/overview/html/occt_user_guides__mesh.html).
### Use from the browser
First, include the `occt-import-js.js` file in your website.
```html
```
After that, download the model file, and pass them to occt-import-js.
```js
occtimportjs ().then (async function (occt) {
let fileUrl = '../test/testfiles/simple-basic-cube/cube.stp';
let response = await fetch (fileUrl);
let buffer = await response.arrayBuffer ();
let fileBuffer = new Uint8Array (buffer);
let result = occt.ReadStepFile (fileBuffer, null);
console.log (result);
});
```
### Use as a node.js module
You should require the `occt-import-js` module in your script.
```js
let fs = require ('fs');
const occtimportjs = require ('occt-import-js')();
occtimportjs.then ((occt) => {
let fileUrl = '../test/testfiles/simple-basic-cube/cube.stp';
let fileContent = fs.readFileSync (fileUrl);
let result = occt.ReadStepFile (fileContent, null);
console.log (result);
});
```
### Processing the result
The result of the import is a JSON object with the following structure.
- **success** (boolean): Tells if the import was successful.
- **root** (object): The root node of the hierarchy.
- **name** (string): Name of the node.
- **meshes** (array): Indices of the meshes in the meshes array for this node.
- **children** (array): Array of child nodes for this node.
- **meshes** (array): Array of mesh objects. The geometry representation is compatible with [three.js](https://github.com/mrdoob/three.js).
- **name** (string): Name of the mesh.
- **color** (array, optional): Array of r, g, and b values of the mesh color.
- **brep_faces** (array): Array representing the faces of the source b-rep.
- **first** (number): The first triangle index of the face.
- **last** (number): The last triangle index of the face.
- **color** (array): Array of r, g, and b values of the color or null.
- **attributes** (object)
- **position** (object)
- **array** (array): Array of number triplets defining the vertex positions.
- **normal** (object, optional)
- **array** (array): Array of number triplets defining the normal vectors.
- **index** (object):
- **array** (array): Array of number triplets defining triangles by indices.
## How to build on Windows?
A set of batch scripts are prepared for building on Windows.
### 1. Install Prerequisites
Install [CMake](https://cmake.org) (3.6 minimum version is needed). Make sure that the cmake executable is in the PATH.
### 2. Install Emscripten SDK
Run the Emscripten setup script.
```
tools\setup_emscripten_win.bat
```
### 3. Compile the WASM library
Run the release build script.
```
tools\build_wasm_win_release.bat
```
### 4. Build the native project (optional)
If you want to debug the code, it's useful to build a native project. To do that, just use cmake to generate the project of your choice.
## How to run locally?
To run the demo and the examples locally, you have to start a web server. Run `npm install` from the root directory, run `npm start` and visit `http://localhost:8080`.