Preload images?

I'm trying to create a Marvel-movie-intro-like effect by starting the timeline at the end, and then successively calling goToPrev() with a short delay between calls, to quickly flip backwards through all the slides.

That all works, but I don't see the images, I only see the grey "loading" square.

I tried to preload the images into the browser cache by using the technique here:

https://stackoverflow.com/a/901699/988264

whereby you just create a bunch of Image() objects and set their src property. That seems to work fine, if I look at my browser tools network tab while the page is loading, it looks like all the images load before the first call to goToPrev(), but I still am seeing the grey "loading" square.

Is there some way to preload the images into whatever cache TimelineJS is using?

Start by reproducing the backward timeline traversal with goToPrev() and inspect how TimelineJS requests and caches slide images. Compare browser-cached images with the grey loading state during rapid navigation. Done means establishing whether preloading can use TimelineJS's cache and documenting or implementing a reliable way to avoid the loading placeholder.