[Therion] xtherion - Multiple background sketches

[Bill Gee]

I finally figured out how to move the background images ...  "Double-right-click" is probably not an accurate description.  Every time I did a true double-click with the right (or alternate) mouse button, nothing happened.  The trick, which I discovered quite by accident, is that you must hold down the right mouse button on the second click.  Do a click,click-and-hold.  With that secret the background images can be moved around.  Getting them positioned correctly, though, is difficult without some transparency.

I have a simple photo editor (Gwenview) but it can only crop a rectangle.  It also cannot set transparency.  I think I will have to spend some time with Gimp.  I hauled it out this morning and figured out how to do a "lasso" selection.  It was actually fairly easy.  I figured out how to import multiple images, setting each one as a layer.  Now I need to figure out how to set transparency on each layer.

I wonder if Bruce's faint memory about setting transparency with an external editor worked because of using PNG format?  My own faint memory is that xTherion uses different libraries to handle png and jpg files.  Handling of transparency is probably a feature of the image library rather than xTherion.

Tarquin mentioned using invisible walls.  I have done that once when I mapped a shelter cave.  That cave (really more of an overhang) was 200 feet wide and about 20 feet deep.  I used an invisible wall to mark the cliff edge that was the outer part.  

For this purpose getting Therion to consider all of the room as "inside" would be a challenge.  I have had situation where joining two passages left a white triangle in the center because Therion did not think that was part of the cave.  I have also done line end-point joins.  Those  are a real pain to keep straight.  They work find when done.  In this case I will probably have to do some of those to get the room joined to the rest of the cave.

The more I look at the sketches, the more I think we need another trip to this room.  I think what I will try to do is merge all the existing sketches, then print them on a single piece of graph paper.  Back at the cave I will add more to that paper.  Scan it and use it for the background.

========
Bill Gee


On Monday, June 21, 2021 1:11:33 PM CDT Martin Sluka via Therion wrote:
> 
> > 21. 6. 2021 v 15:54, Bill Gee <bgee at campercaver.net>:
> > 
> > 1) Is there a way to drag/drop reposition a background image?
> 
> Doubleclick with right button
> 
> > 2) Is there a way to make images transparent?  I tried fiddling with the gamma slider but it did not do anything for transparency.
> 
> No
> 
> > 3) Is there a way to crop off arbitrary sections of a background image?  Some of the sketch pages also have cross-sections, and those will seriously confuse things when trying to place objects.  I would like to crop them out.
> 
> You should do it in external photo editor but in xTherion you may easy switch order of background images.
> 
> > 4) Is this something that I need to do in an external image editor like Gimp?  I have not used Gimp in several years.  The learning curve is daunting.  
> 
> Try any simple photo editor - most of them are able to crop a part of image.
> 
> Adobe Spark https://www.adobe.com/express/
> https://www.nchsoftware.com/photoeditor/index.html <https://www.nchsoftware.com/photoeditor/index.html>
> and many more.
> 
> As a tip: compile with sketch included as .xvi may help you much. 
> 
> Martin
> 
> thconfig:
> 
> source ./th2_pro_xvi/colibri_2_xvi.th
> 
> #sketch-warp plaquette
>   
> layout morf
>   sketches on 
> endlayout 
> 
> export map -o ./output_xvi/4115-4116-4117.xvi -layout morf
> 
> 
> 
> 
> 
>