Found this site online after a lot of scratching my head on how to convert my 3D models to usable formats for Q3D. (As I'm using Maya LT and it doesn't support any 3rd party exporters) I didn't play around with it much yet, but tried converting some fbx files to Three.js (used by Q3D) and seemed to be working good so far.
You can upload these formats:
FBX, Collada, OBJ/MTL, STL, JPG, PNG, blend, bvh, cfg, 3dc, txp, osgterrain, terrain, jpg, jpeg, step, stp, igs, iges, brep, brp, csg, fcstd, oca, gcad, shp, pov, png, x, geo, tga, pbm, pgm, pnm, ppm, bw, int, inta, rgb, rgba, sgi, gdal, bmp, gif, dds, exr, ico, pcx, pfm, pict, pix, ac, lws, lwo, 3ds, tif, tiff, hdr, iv, wrl, wrz, pic, stl, obj, dae, xgl, zgl, ply, lxo, csm, irrmesh, irr, smd, vta, 3d, md5, mdl, md2, md3, pk3, mdc, nff, off, b3d, q3d, q3s, hmp, ndo, mtl, jsfbx, fbx, json, js, txt, text, md, markdown, claramats, clara, claraarchive, zip, 7z, rar, vismatzip, vismat, vrmatzip, vrmat, vrscene, vrscenezip, foyr, onshape, onshapeassembly, scmat
Tip: For best results, use FBX with embedded textures.
after uploading your scene files, you can download as..
Autodesk FBX (.fbx)
Clara Archive (.clara)
STL 3D printing (.stl)
Wavefront OBJ (.obj)
Web3D extensible 3D (.x3d)
They also have an editor which I haven't tried much but it seems pretty capable for editing and modeling.
Besides from that they also have a huge library if free 3D models.
Might be worth a try if you're planning on trying Babylon or Q3D. They have a limited free option, but a pretty cheap monthly option too if needed.
Check it out here: