Adding Terrain data/viewing

[Graham Mullan]

Again, shouldn't this be going to the full Survex list?

The issue with Phil Underwood's patch, as I understand it, is that it 
still requires someone to spend time digitising a map. This 'should' be 
considered a waste of effort when DTM data can accessed for free from 
NASA, which is exactly what terraintool does.

The issue with that data is that it is not very good in steep terrain. 
This is a problem with the data not with Survex and how it utilises it. 
Had I the time (Andrew Atkinson is cracking the whip to get me to work 
on the survey we are entering for the Hidden Earth competition) I'd use 
terraintool to generate a 250 m grid for Matt's area to see how it 
compares with his version. However, surely the point here is to think 
about ways of importing other sources of DTM data which may be better 
than the free stuff in certain areas. The free stuff is fine in 
relatively level terrain, anyway, and there will always be problems 
associated with the accuracy of DTM data whatever the source.

I agree that it would be a nice tweak to colour the surface file 
generated from DTM data differently to that generated by surface line 
surveys. That's a different point.

Final point. Wookey, especially, has been talking about integrating 
Survex with wider co-ordinate systems. Where's the issue? Every time 
I've made a surface overlay I've done exactly that. I have 3d models, 
with surface from the UK (OSGB) from Ireland (IOS, ITM and a working 
combination of the two) and France (UTM, I think, it was a couple of 
years ago - just checked it was UTM31). This is not an issue that 
actually stops anything being done.

Graham
--
graham.mullan at coly.org.uk

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On 18/09/2013 10:20, Matt Kirby wrote:
> Olly
>
>  > There is, but we really need something which is usable in general,
>  > rather than specific to a particular survey project.
>  >
>
> I'm not quite sure what you mean by this. Surely the terrain patch Phil
> did for us would be 'usable in general'. We've certainly found it to be
> a useful tool. In fact I'd like to see the LNRC survey
> http://www.ubss.org.uk/resources/surveys/survex/LNRC_with_surface.3d  or
> or Duncan Price's
> http://www.sump4.com/downloads/fairy_cave_quarry.3d with Phil's blue
> *terrain lines rather than using the existing *surface feature.
> Is Phil Underwood still around and involved with Survex?
> Cheers
> Matt