a step loader would be complex to implement, the triangulation is probably too expensive for javascript. at work we’re building https://buerli.io which is an embed cad system, it supports step/iges and it’s directly wired into threejs.
it’s in the last stages and we finally have a wasm module working in the browser. if you need it quick you can write them a mail and request access, we’ve already sent it to a couple of people that are testing it currently.
here’s a small example app built around the embed cad. it’s loading a step assembly, displays it, and shows the tree structures. the actual code that loads and displays it is around 1-3 lines of code: init(), load(…), scene.add(model)
