Spiral wormhole, great for scifi renders. Made with Blender 2.82 and rendered in cycles. The lighting was achieved with 2 light sources; 1 light source in the bottom of the wormhole to light up the centre, and another light source at the top to provide ambient lighting.
BLEND (Blender, filesize: 1.15 MB), FBX (Autodesk FBX, filesize: 913 KB), GLTF (glTF, filesize: 1.48 MB)