I need Three.js Expert

We have created a streetview-like app using [login to view URL] SphereGeometries. The user can change places and the view similar to google and apple streetview. At the moment, the transition effect is very hard, as our sphere geometry is being disposed and rebuild. We would like to achieve a smoother transition from scene to scene, maybe using a fading effect or zooming effect when going forward or backward. We have added a video from apple streetview and a video of our actual app as well as the source code project of our app. Please make a proposal of your idea and how the transition effect could be implemented. It does not have to be exactly as in the apple streetview video but it should be a smooth effect and the user should have the impression to be moving along the way. budget is 150$