[Therion] Outside and inside / Vertical smearing of 3d Models

[Andrew Atkinson]

On 23/06/10 10:48, Bruce wrote:
> Your example would make a nice addition to the therion projects page
> http://therion.speleo.sk/wiki/doku.php?id=projeurope
>
> You might like to add it, or give permission for someone else to

It is on my list of things to do
>
>>Lots of the 'smearing' is from made up surveys, constructed from old plans.
>
> I have had this effect where drawings extend beyond the influence of
> survey stations (both 'real' and 'made-up' surveys).  Any tips as to how
> to prevent or minimise this?

It is good to have further evidence for this, it was my theory also.
>
> The Longwood cave (in the Charterhouse set above, screenshot below)
> seems to have a matching survey centreline and model when viewed in
> plan, but the model is still smeared and the elevations of the smeared
> 3d model do not match the survey centreline.  I assume this is because
> the drawing is not ‘connected’ to the centreline by way of point
> ‘survey-station’s, and if it were, presumably this view would become the
> more realistic 3d tube we are accustomed to.

The longwood survey, the centreline does not match the plan. we suspect 
that, as we do not have the original plan, the version we have has been 
sheared and twisted by copying so only 2 stations are used in the 
scraps. I seem to remember that if no height information is given it 
makes it proportional to the width, and does not use the X-sections, so 
I am hoping that if we add some height points we will get better output 
in the lox model

thanks

Andrew