Model Based Definition

Is there a way to display model based definitions (measurements and tolerances) with three js?

I’m not sure what you mean by this… is there more information about “model based definitions” somewhere? Are you expecting that these measurements and tolerances are contained in the model itself, and if so what sort of file format are you using? Three.js does not compute such things about a model itself, nor does it deal with real-world units except as needed for physically-based rendering.

Sometimes MBD is used interchangeably with PMI (product manufacturing information).

These measurements are often used with STEP files and are within the model.

I see. three.js cannot load STEP files directly (see https://github.com/mrdoob/three.js/issues/7125 for alternatives).

The short answer would be that while three.js gives you a toolkit to draw lines and text anywhere, drawing geometric dimensions in the particular style common to CAD software would be left up to your application. You may find examples elsewhere that would be helpful to follow, like https://stackoverflow.com/questions/25432540/draw-dimension-lines-along-with-3d-cube-using-three-js.