[Therion] Cave Overlays on Google Maps Web Sites

Stacho Mudrak s.m at group-s.sk
Tue Jan 30 15:19:39 CET 2007

Quoting Wolfgang Zillig <wolfgang.zillig at web.de>:
> perhaps one alternative would be to implement shapefile support and to
> use gdarwarp and/or gdal_translate to create kml. But I don't have any
> experience with the kml format.

I have forgotten, shapefiles are also already implemented in the last  
developement snapshot (including user defined object attributes) ;)

export map|model -fmt esri

should create a directory with shapefiles for different shapes. If you  
have georeferenced data, also associated .prj files are created.  
Tested on free QGIS and ArcExplorer. I am just not able to display 3D  
triangle strips.


> But shapefile would be a nice link to the gis world!
> Greetings
> Wolfgang
> Stacho Mudrak schrieb:
>> Quoting Bill Chadwick <W.CHADWICK at sky.com>:
>>> As this is quite a nice way of presenting cave surveys, perhaps a Google
>>> tile generator would be a good add on for Therion. The advantage   
>>> of building
>>> the renderer into Therion would be that the overlay could be drawn
>>> separately for each Google Zoom level to achieve a good line width and text
>>> size.
>> Hmmm. Just one problem. Therion it self does not have any build-in   
>>  bitmap generator. All maps are generated as vector PDF. And   
>> generation of bitmaps from PDF is very tricky (currently only   
>> Acrobat reader is  able to render these PDF files 100% correct).
>>> I am well informed in the areas of coordinate systems and map projections
>>> and able to program in C++. With some guidance I might be able to help with
>>> the coding of such an extension.
>> I have tried to generate Google Earth's KML files from therion and   
>> it  seems to work (scrap outlines for maps, centerline for model,   
>> try  latest developement snapshot). All you need is to have   
>> georeferenced  cave data (see "Coordinate Systems" in thbook). Then  
>>  just
>> export model -fmt kml
>> will generate .kml file readable by Google Earth.
>> If somebody will create a good rasterizer script for PDF files    
>> generated by therion (using ghostscript or acroread), there is no    
>> problem for us to add export of long-lat coordinates together with   
>> PDF file to be used by this script.
>> S.
>> _______________________________________________
>> Therion mailing list
>> Therion at speleo.sk
>> http://www.speleo.sk/mailman/listinfo/therion

More information about the Therion mailing list