allow the ability to load a different time from time series

[toloudis]

Use Case

Microscopists want to view time series zarr data using web viewer in the near-term.

Solution

Internals implementation separate from ux:

• make sure we can select time when loading zarr files by url (website-3d-cell-viewer only?)
• we need a prop so that embedding apps can fully specify the volume data to load (Can't quite remember if we made a LoadSpec prop that can have fields like time).
• could experiment with a temporary time slider in dat.gui or tweakpane (see #92)
• default loading time 0 if unspecified

If the volume loader detects time series, we can present a time slider. On changing time slider, request volume data with all settings the same as currently loaded except for a different time index. Time slider should be presented via experimental ui according to #92

[toloudis]

It would be good to have consistent usage patterns across Agave and the web viewer for dealing with time series (and overall).

[toloudis]

This can consider zarr-only for now. We need not make other attempts to do time series loading yet.
There is another possible use case in which the time series may be in a sequence of separate files as opposed to one single zarr url. We would have to consider how the sequence of separate files would be specified.

[frasercl]

After some discussion, first steps for this API should be:

• The createVolume method on IVolumeLoader should be split into two methods:
  • createVolume, which creates a new Volume object with the correct properties as specified by a LoadSpec but does not fetch any data;
  • and something like loadVolumeData, which actually fetches data and places it in a preexisting Volume
• Volumes should keep hold of their own LoadSpec
• The View3d method for loading different time points in a time series should look like setTime(volume: Volume, time: number, loader: IVolumeLoader), which just modifies volume's LoadSpec and calls loader.loadVolumeData(volume);.
  • Though come to think of it, could this function also pick and create the appropriate loader? Perhaps loader can start as an optional parameter for in case loaders ever start maintaining their own state.

[frasercl]

Above API was implemented in #104, but I didn't mark this issue as resolved because that API seemed to be tentative/transitional. But remaining work towards a final polished interface may be better tracked by a task under allen-cell-animated/website-3d-cell-viewer#155?

[toloudis]

If the demo viewer time slider in volume-viewer can use the new api (directly or indirectly) then we can close out this ticket. The initial description is purposely excluding the website-3d-cell-viewer layer. Any refinements can be in new tickets.