Colouring by date

[Mike McCombe]

Hi Olly,
Last week you wrote...
> 
> Erin had a cave which had a vast entrance pitch with a fairly flat cave
> below, which resulted in all the colours being used up by the entrance
> pitch, which is similarly annoying.
> 
> We had two ideas to improve that (neither implemented yet).
> 
> One was to make the depth band widths depend on the length of passage at
> that depth.  More passage gets tighter bands.  But that does mean the
> colours change as you survey more, even if the cave doesn't get deeper.
> 
> The other was to allow the user to choose the depth band divisions.  But
> that's kind of fiddly - something automatic is nicer if it works well.
> 
> But to address both this issue and yours, perhaps the answer is to
> implement restricting the view (or the colouring at least) to a
> subsurvey (or set of subsurveys).

I have just added surface topology to my survey, flagging the points as
"surface". Aven doesn't colour these surface points (which is fine) but it
does take account of their altitude when calculating the range for the
colour bar. The end result is that I have rolling mountains (all white) over
a cave which is all in blue. Would it be feasible to base the colour scale
only on those items which are going to be coloured?

Best regards,
Mike