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replicad as a library

At its core, replicad is just a library. You can then create your own viewer, editor, configurator on top of it.

In order to show what can be done in the most simple way, you can find a sample app here:

Display of the model

With replicad you can easily export an STL (or STEP) file to be opened in another application. Nevertheless displaying a model in your page tends to be nicer.

For this you will need to use a 3D library. For instance, replicad has helpers to integrate with threejs.

opencascade.js and webassembly

Most of the complexity in using replicad as a library is that it depends on a webassembly module, opencascadejs, and the tooling around WASM is not always easy to use.

Additionally, you should load the webassembly code from opencascadejs (or the replicad custom build) in a webworker. The model computation can take some time and the parallelism of a worker will allow you to offer a reactive interface during the computation.

Injecting opencascadejs

The important bit you need to do to have replicad work is that you need to inject an instance of opencascadejs at initialisation.

You can have a look at the initialisation in the sample app:

let loaded = false;
const init = async () => {
if (loaded) return Promise.resolve(true);

const OC = await opencascade({
locateFile: () => opencascadeWasm,

loaded = true;

return true;
const started = init();

In addition to the opencascadejs boilerplate, we use the setOC function. This will inject the instance of the opencascade library into replicad.

Once this is done, replicad will work.