I'll upload to the zone a couple of demo packs that used to be available at
www.vgr.com.
Other than that, there is Tornado3D and Adescent 0.7virge or 0.8 w3d. After that its down to any warp3d software.
Edit: With new winuae.exe 3d support shows first signs of life! Warp3D demos are working with 68k and ppc. They look odd, but they are running.