Is there a 3D equivalent (technical or spiritual) of SVG? I've been working on a CAD visualizer, and I'm looking for something lightweight that I can use to build up representative changes to cad models without having to do a full loop through the CAD application, pull a full .step export, and visualize that.

SVGs will work nicely for showing 2d sketches, but I'm hoping for something similar for the models themselves, without the slowdown of having to use the underlying CAD software for visualization.