‘Onshape is the first and only full-cloud 3D CAD system that lets everyone on a design team simultaneously works together using a web browser, phone or tablet. Create complex parts, assemblies, and detailed drawings all within your web browser.’
a bit off-topic maybe, but ROS ultimately uses assimp to load meshes (or at least RViz does). You should be able to use any of the formats assimp supports, besides STL, Collada and ogre formats.