THIS IS HOW WE DO IT!
After a couple of days of Googling, faffing, trying apps and getting nowhere, I finally managed to find out how to achieve this. I’m really
surprised no one else has posted regarding this as it seems like it’s pretty fundamental to be able to make tours work offline.
To see an example of what I’ve done, go to
https://www.chrisl.me/vr/blueball/. As you’ll see, it takes a while for the first panorama to display and that’s because all the other panoramas and audio are downloading in the background. Before you click to go to the next panorama, disconnect your computer / smartphone from the Internet. Then, when you go to the other panoramas, you’ll see that the images and audio correctly load, even though you’re offline.
Here’s what you need to put into the tour.html file. For
each image you need to have a line such as:
<link as="image" rel="preload" href="https://www.chrisl.me/vr/blueball/panos/01_Main_Bar.tiles/pano_b.jpg" />
For the audio, it needs to be:
<audio id="01" preload="auto"><source src="https://www.chrisl.me/vr/blueball/audio/01.mp3"></audio>
If you check out
https://www.chrisl.me/vr/blueball/tour.xml you’ll see how I’ve added the audio to the panoramas.