Make the direction of travel obvious with each Z slice transition

[clbarnes]

This would be a major help for pair tracing, where it's otherwise difficult to communicate with the partner which way you're going. It would also help orient people to which branch is more likely to be towards the brain etc.. Obviously this is possible by watching the Z spinner, but something like a big pair of arrows in the corner of the tracing window which light up for a short period with every transition would give the user and any viewers more of an intuitive feel. Making them the same colours as the cross-z edges would also help build the intuition there.

[aschampion]

This is definitely disorienting even when you've just handed control over to the other person so know what structure to expect in each direction.

Should note this is way less of an issue with orthoviews open.

[schlegelp]

+1

[clbarnes]

Should note this is way less of an issue with orthoviews open.

Yes, maybe it could be disabled in the stack viewer settings.

[tomka]

That a good idea! However, it isn't immediately clear to me which Z direction should be represented by what transition arrow direction, i.e. is the next section an upward arrow or a downward error? Z grows while moving through the stack and the upward arrow on the spinner will move in this direction, too. Showing an upward arrow to highlight the transition direction would be consistent with the spinner and the growing number, but doesn't feel like the right symbol for the transitioning to the next slice to me. However, flashing a downward arrow for the transition seems better in that regard, but is inconsistent with the spinner and the Z coordinate. Maybe using icons other than errors might be better: for instance something like fontawesome's layer group icon, but with only the bottom layer filled if moving in +Z and only the upper layer filled when moving in -Z.

[clbarnes]

Yes, for whatever reason my intuition is that I am looking down on a stack; moving forwards is moving downwards. Thinking about it as "forwards" and "backwards" helps (and is consistent with the mouse wheel), although where that fits into . and , (or as I remember them > and <) is yet another question.

I feel that icon still has some up/down implications to it, but something like a rotated version which "felt" more forwards-backwards, possibly with additional arrows coming out of each side which could also light up, may be more helpful.

I suppose the simplest way around it would be to eschew arrows entirely in favour of + and -, which maps unambiguously to the Z value.