<html class="apple-mail-supports-explicit-dark-mode"><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div dir="ltr"></div><div dir="ltr">Hi,</div><div dir="ltr">this is how we do it with our 120km project.</div><div dir="ltr">Additionaly, we also divided the Cave into regions, which are composed of individual surveys. Historically, each survey is one passage, and new „days“ are added as new centreline, however sometimes we also model it as new subsurvey (depends on data size and also personal preference).</div><div dir="ltr"><br></div><div dir="ltr">But that does not matter much: we leverage therions capability to differentiate sketches and data: each centrelines has its clearly matching set of source data (like scanned sketches or digital drawings).</div><div dir="ltr"><br></div><div dir="ltr">Can you please elaborate more on the use case: why are you even redrawing manually?</div><div dir="ltr"><br></div><div dir="ltr">In our data this can only happen if the original data was horribly wrong. In all other cases we amend just the th2 file (when cave content is added or revised; usually a generated, printed and pencil-ammended pdf is then the source image; ie. it has perfectly matching stations in the pdf based on the distorted centerline).</div><div dir="ltr">When just the centerline is ammended, we let therion adjust the map. And if we resurvey, we draw the new stations into the old pdf and th2, so therion knows the new stations in relation to the old drawing. This all can also be mixed with not too much hassle.</div><div dir="ltr"><br><blockquote type="cite">Am 17.09.2026 um 12:48 schrieb Bruce Mutton <bruce@tomo.co.nz>:<br><br></blockquote></div><blockquote type="cite"><div dir="ltr"><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><div dir="auto">Jean-Florent</div><div dir="auto">Briefly, Therion works best when you give it small independent chunks of data (xvi, one days survey, small scraps, one days th2). These should never be amalgamated with the next days survey, but are instead connected up using surveys made of sub-surveys and maps made of sub-maps.</div><div dir="auto">Each xvi and the should only be created once and never amended with the next days survey. Else the effects you describe come into play. </div><div dir="auto"><br></div><div dir="auto">Putting everything in one big file is probably the worst possible approach. </div><div dir="auto"><br></div><div dir="auto">Good approaches are described in a number of places on the wiki. I just don't have good access at the moment to provide specific links. </div><div dir="auto"><br></div><div dir="auto">Bruce</div><div dir="auto"><br></div><div id="composer_signature" dir="auto"><div style="font-size:14px;color:#909090" dir="auto">Sent from my Galaxy</div></div><div dir="auto"><br></div><div><br></div><div align="left" dir="auto" style="font-size:100%;color:#000000"><div>-------- Original message --------</div><div>From: Jean-Florent Raymond <jeanflorent@no-log.org> </div><div>Date: 17/09/26 18:49 (GMT+12:00) </div><div>To: Therion List <therion@speleo.sk> </div><div>Subject: [Therion] Good practices for xvi files? </div><div><br></div></div>Hi all,<br><br>I have some problems with xvi files so I wonder if I do things the right <br>way.<br>Like many of you I guess, I use to draw incrementally. That is, I have a <br>therion project that compiles to a map of a cave we are currently <br>exploring and when we discover new stuff, we survey it and I add it to <br>the map with the following steps:<br><br>1. Add the new data in a new th file to the project folder.<br>2. Compile to update the xvi file.<br>3. Open the drawing with xtherion and draw the part of the cave <br>corresponding to the new data.<br>4. Compile to get a pdf.<br><br>(in particular in this example there is a unique xvi file and a unique <br>th2 file for the whole cave)<br><br>The problem is in step 3 when I open the drawing with xtherion. <br>Sometimes the updated xvi is shifted compared to the existing drawing, <br>possibly because it does not have the same dimensions as previously. <br>This is annoying but can be fixed by manually positioning it. However if <br>I close a loop then the xvi centerline is distorted (to distribute along <br>the loop the unavoidable error) so in xtherion the previously draw map <br>does not correspond at all to that centerline.<br>Problems:<br><br>- I have to position the xvi manually (this cannot be avoided I suppose)<br>- Only the new parts of the cave can be drawn on the xvi, because the <br>old ones do not correspond anymore. In particular I cannot easily rework <br>previously drawn parts of the cave.<br><br>I tried to think of different solutions:<br><br>a) Generate a different xvi file for each time I add data, so that I can <br>always open in xtherion an xvi file that matches the part of the drawing <br>I am interested in.<br>b) Accept that the xvi file will only match the latest part of the <br>drawing and each time I add data, fix it position with respect to the <br>station where the new data starts.<br>c) Use a version control software like git, so that I can easily find in <br>the history a version of the xvi file matching the part of the drawing I <br>want to work on. (I would like to avoid this option because when <br>teaching therion to beginners there is already a lot to tell and I do <br>not want to add git on top of that.)<br><br>What about you, how do you deal with that?<br><br>Best,<br>Jean-Florent.<br>_______________________________________________<br>Therion mailing list<br>Therion@speleo.sk<br>https://mailman.speleo.sk/listinfo/therion<br><span>_______________________________________________</span><br><span>Therion mailing list</span><br><span>Therion@speleo.sk</span><br><span>https://mailman.speleo.sk/listinfo/therion</span><br></div></blockquote></body></html>