Corona Renderer is the modern advanced high performance renderer for 3ds Max, Cinema 4D and more.
The order is as follows: 1) upload to the site spherical panoramas from which you plan to create a virtual tour; 2) from the list of uploaded panoramas add each panorama to the virtual tour (Add to 3D tour link); 3) open the created virtual tour, edit the panorama order, select the main panorama, set transition points (tunnels).