[Therion] How to generate a projected elevation along aspecificbearing?

Footleg drfootleg at gmail.com
Tue Mar 22 23:09:29 CET 2011


Thanks Bruce, that is most helpful and makes everything clear.

One of the things I struggle with as a new user of Therion is the
documentation. In this case I found nothing about projected elevations in
any examples of on the wiki. The therion book gave me the pointer to put the
projection bearing on the scrap type, but I was only able to work out how to
set this in the xtherion map editor by editing my th2 file in a text editor
and then reopening it in the graphical editor to see what changed in the
scrap options pane. I didn't come across the fact that elevation bearings
needed to be specified in the map protection declaration in the th file, or
in the export map declaration in the thconfig file. I do wonder why if I am
declaring everything in the map / endmap block in the th file, and I give
that map a name there, then why is it not possible to specify that map by
name in the thconfig file export, rather than have to repeat the map type
information and have therion try to work out what map from my th file to use
to generate that pdf? Just a suggestion.

I am happy to write a general introduction/walk through and provide an
example project for the wiki if someone can set me up with an account to
allow me to edit wiki pages.

Footleg

On 22 March 2011 19:10, Bruce <dangle at tomo.co.nz> wrote:

>  OK, a few routine syntactical things to sort out here, no bugs.
>
> Firstly to help debug I showed the centerline and added debug all to the
> layout.  Then I could see what was going on.
>
> It was apparent that with no projection orientation the elevation scraps
> were screwed up (upside down).  Try it with the original file set Footleg
> sent, you will see.  This is expected behaviour with a scrap drawn in one
> orientation and then morphed to another.
>
>
>
> Second I pulled the map object definitions outside of the survey structure
> in the th file.  Not sure if this was a problem, it’s just the way I’ve
> found works best for me.
>
>
>
> Third the definitions of the elevation all need to match.  Remember that if
> we are using integer orientations there are 359 possible elevation types,
> and if anywhere it is undefined it defaults to ‘north’.  This was the main
> problem here.
>
>
>
> In the attached you will see I have added;
>
> -projection [elevation 090 deg]
>
> To all of the *elevation scraps*, the *elevation map* definition in the th
> file and the *export elevation* statement in the thconfig.
>
>
>
> Hope this helps.  I guess the Therion Book and the wiki could have a bit
> more on this.  Drawing elevations is one of the very basic functions after
> all.
>
>
>
> Cheers
>
> Bruce
>
>
>  ------------------------------
>
> *From:* therion-bounces at speleo.sk [mailto:therion-bounces at speleo.sk] *On
> Behalf Of *Footleg
> *Sent:* Tuesday, 22 March 2011 11:39 p.m.
>
> *To:* List for Therion users
> *Subject:* Re: [Therion] How to generate a projected elevation along
> aspecificbearing?
>
>
>
> This is a small learning project, so I've attached all the files apart from
> the bitmaps.
>
> I think there is a bug lurking behind these problems. I am using Therion
> build 5.3.6 on Windows. I tried adding a projection direction of 090 to both
> the scraps in my elevations th2 file, even though only one of these scraps
> was included in the map in the th file at the time. This caused a long list
> of errors when trying to generate the elevation pdf. So I removed the 090
> from after the word 'elevation' in the projection box for both scraps.
> Including the second scrap in the map block with no projection direction
> declared now results in what looks like the output for the first scrap
> duplicated in the elevation pdf with both 0 and 90 projections. Hopefully
> you can easily reproduce these problems with the attached files. I've left
> both scraps included in the map for the elevation. But you can comment out
> the 2nd one and then try to set a projection direction of 090 on both scraps
> in the th2 file and get the errors. Why does changing the projection
> direction for the second scrap cause the pdf generation to fail even if that
> scrap is not used in the pdf?
>
> Footleg
>
>  On 21 March 2011 19:27, Bruce <dangle at tomo.co.nz> wrote:
>
> Footleg
>
> May need to include your th and th2 files to be more specific…
>
>
>
> Couple of likely issues.
>
>    1. Firstly check that the direction of the projection is the direction
>    in which you are looking.  Ie on the elevation the direction will then be
>    ‘into the page’.  If you don’t specify a direction then Therion assumes it
>    is north.  I would guess you have some scraps/maps with differing projection
>    directions, and so naturally they are different projections.  If you have
>    for example 3 different projection directions, then therion will make three
>    elevations (if you ask to export them).  Look in the log file or Xtherion
>    compiler map structure pane for clues.
>    2. Make sure every scrap and map you want to include in this elevation
>    has the same projection.  Many versions ago I found that Therion assumes 0
>    is not the same as 000 and 20 is not the same as 020.  So I always use 3
>    digit integers these days.
>    3. Differing coordinate systems.  If you for example use a different
>    thconfig for the main map production and test plots of parts of the cave you
>    might be using different coordinate systems or declinations each time.  This
>    will really screw up the elevations where passage is almost in the same
>    direction as the projection, because Therion will morph as much as required.
>    In this situation it often turns into a real mess.
>
>
>
> Bruce
>
>
>  ------------------------------
>
> *From:* therion-bounces at speleo.sk [mailto:therion-bounces at speleo.sk] *On
> Behalf Of *Footleg
> *Sent:* Tuesday, 22 March 2011 2:59 a.m.
> *To:* List for Therion users
> *Subject:* [Therion] How to generate a projected elevation along a
> specificbearing?
>
>
>
> I've tried searching the wiki and Therion book to find an answer to this,
> but it does not seem to feature anywhere. Not even in any examples I can
> find. I am trying to draw a simple cave with a 20m vertical entrance shaft,
> and a couple of chambers down a slope at the bottom. I've drawn an elevation
> scrap for one of these chambers and the shaft. But when I generate an
> elevation map using this scrap the shaft looks fine, but the chamber wall is
> a mess. So I concluded it is not projecting the elevation along the bearing
> I would like. The Therion book showed me I can put a bearing on the scrap
> type. So I tried elevation 90. Now my shaft is no longer appearing anywhere
> near vertical in the elevation PDF and the chamber. Can anyone help me
> please?
>
> Screenshot of scrap, and pdfs with default elevation map and elevation 90
> settings attached.
>
> Footleg
>
>
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