How to produce better thumbnails for the Featured Gallery?

[gwhitney]

Kate Stange writes:

I'd like to be able to set a custom delay time on the thumbnails for specimens. Currently it is 4000 milliseconds. Some need more time to look good in thumbnails, but I don't want to uniformly increase it, or even increase it uniformly per visualizer type. Some specimens are just slow.

Looking forward, this isn't just something useful for the gallery, but something that we might want when we have saved/archived specimens etc.

Currently specimenQuery() returns the query itself only. One option is to have specimenQuery() return, besides the query (url) itself, a variable thumbDelay. This would just be originally passed into specimenQuery() inside defineFeatured.ts, so it's easy to set on each specimen. This seems simple enough that I think I could do it. It seems this function isn't too widespread.

Another option would be to encode a delay in the query or URL itself, but maybe this breaks some paradigms.

Or I could do something more kludgy to avoid changing specimenQuery()'s return type.

Or something else.

Advice?

[gwhitney]

Hmmm, @katestange and@Vectornaut, three thoughts come immediately to mind:

1. I am already a bit concerned with the computational burden of the featured gallery, and it is already not too attractive that a bunch are waiting for WebGL contexts. So we could just go ahead and capture and store once-and-for-all images for each featured visualization, and just serve up the image (don't run the visualizer at all). After all, we already switch from the "live" visualizer to a static snapshot after a timeout (something like 4 seconds), so why not just put up our desired snapshot right away?

2. We already use frames=NNN&... query components in the e2e testing, so we are already all set up to do that. So rather than having a timeout like we do now, we could put in a default number of frames NNN for thumbnail visualizations, but allow each specimen to override this number of frames. (Note we would then still have to leave in the code that switches to a snapshot so that the WebGL context is released for use by other thumbnails, but the trigger could be either the visualization has stopped drawing or a much longer timeout has elapsed.)

3. Bite the bullet and implement the planned feature that only the thumbnails that are on-screen are drawing, and make sure that the layout is such that there are always enough WebGL contexts for the ones showing. Then all of the (visible) thumbnails can just be allowed to draw indefinitely.

Any of those sound good?

[katestange]

I vote not 3., at least in this Featured Gallery PR coming up -- I have very limited cycles before Paris. I think I could fairly easily figure out how to do 2. in this PR. I'm less confident about my ability to do 1. in this PR.

Arguments for/against 1. I'm concerned about the burden also, and it makes it look a little broken. OTOH the liveliness of seeing them growing in is quite nice.

For/against 2. It seems easy and will fix the most unaesthetic aspect of the gallery, which is that some quite nice specimens come in rather badly at the moment.

If we do 1., a combo of 1. and 2. could be to pass a flag for a static thumbnail which could be used for some but not all of them (some are slow to start looking pretty, whereas some are exciting to watch move). This could allow for tweaking the gallery in quite a nice way.

3. really sounds more like beta to me

So, I think I would be happy with either 1. or 2., but I may need help with 1. if we go that way. How much work is that? I'm worried it may also be beta, or at least a separate PR, just in terms of scope.

[gwhitney]

Sorry I was preoccupied with a major milestone for mathjs yesterday. Given your perspective, why don't we just go for (2), only, now and leave this discussion open to guide further tweaks/improvements for beta? I don't really see any downside for that. I'd recommend some default number of frames that's decent for most thumbnails, with an option to adjust that default. The only slightly tricky bit is that somehow we have to make sure there's no frames=NNN& clause in the query when the featured specimen is then clicked to open in its own window... if you need a hand on the technical aspects so you can get the content selection done in time, just let me know.

[katestange]

For future: Instead of thumbnails, maybe we should even capture animated gifs somehow?