Elk issue with sTopo Component (Several .hgt files)

I’ve run this component a thousand times but have never encountered a problem. The sTopo component keeps on hitting an error for some reason.

My first assumption was that I was trying to add too many SRTM .hgt files. The Osm data overlaps 4 different tiles so I thought that could have been the issue. I have no managed to combine all 4 into a single .hgt file (using SAGA GIS). The issue is still coming back as: “Solution exception: Invalid U and V counts”.

Has anybody encountered this problem? Or know what can be done to solve the issue? I found this post:Elk topography, which is kind of my issue, without a conclusive solution.

GrasshopperHelp.zip (14.5 MB)

Got the same problem yesterday. Did it thousands times already but sometimes it doesn‘t work even if my area is 100% inside the .hgt file… would be really nice know what’s going on there.

That’s it! there is no logic to it. I’m a bit perplex to why this happens…

So it seems the points exist but they are being mapped at the wrong location… It’s as soon as I plug the longitude latitude that the component throws an error back.

It just seems like no body has a clue how to solve this issue. I’ve seen several post on other websites from people having the same issue but never finding a solution to it.

Hi @Tompouce4

I encountered the same problem often with Elk. Sometimes it worked out, sometimes not.
I would recommend to try the Terrain Component from GISMO ( https://www.grasshopper3d.com/group/gismo) Its a great plugin to harvest OSM-data or free GIS-Data.
It lets you to choose different servers to automatically download the hgt files and import them to rhino.
I used it thousand times , without any problems. It also has more functionality than Elk in my opinion ( generatig old-town-roofs etc.). And the option to choose from different sources of the terrain-files is very neat :slight_smile: thansk again @djordje for this great plugin!



Thanks @bumaye ! I’ll have a bit more look into it. Tried it out a few months back without being able to make it work so i’ll spend A bit more time to try and figure it out.

@burmaye the plugin is really interesting it has sorted out my problem of finding the topo. It is really an amazing plugin. The grasshopper scripts does all the work for you. The only thing that I do not understand is that the information coming through from osm is pretty selective. For the area I am looking at no roads are coming through nor can I select easily what is represented by the OSMshapes component. It just seems like it lets everything through which doesn’t allow for baking data seperatly. Any idea how to do that?

Sorry this post has slightly changed of trajectory.

GISMO allows you to filter the osm-data with highlighting specific values/keys. Check the example to get the idea, how to sort the data you get. You can extract specific shapes etc.
Another option would be to combine Elk and GISMO. But you have to be aware that GISMO place the geometries to the origin ( 0,0,0) and Elk to some other point ( earth anchor point? ).
I hope I could helped you.


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your answers are definitely very useful, thanks a lot! Just managed to make it work and the level of detail is incredible!

@bumaye would you know what the projection is of the data coming out of Gismo? I’m trying to underlay the data I had from .Shp files onto the data found through gismo but the projection seems always wrong I’ve just assumed it was the same as osm, which is WGS84 EPSG:3857. Is that right? I’ve been reprojecting my .Shp files with QGIS following this post: https://gis.stackexchange.com/questions/73686/changing-projection-of-shapefile-in-qgis

Please let me know if that seems correct as the process takes a bit of time and I have been doing several times trying to get it just right…

Hi @Tompouce4,

For the OSM and terrain data, Gismo is using UTM (Universal Transverse Mercator) coordinate system and Transverse Mercator conformal projection to project its vector and raster data.
Both vector and raster open source data are downloaded as WGS84 coordinate system.

If I understood you correctly, you would like to know your EPSG code for the location: “Homalin, Myanmar”?
Check the attached file.
location_to_EPSGcode.gh (42.3 KB)

Hi @djordje,

Thank you for your answer back. That’s really useful to know as there are 1000’s of different projections to choose from with QGIS.

I’ve finally managed to locate the projection you mentioned and thank you by the way for sharing the script to find out the proper ESPG code. I’ll test the new projection out in Gismo see how it all comes out.

For some reason even after re projecting with QGIS to the projection you specified leads to the curves of my roads shapefile to still be slightly skewed compared to the geometry coming out of Gismo. It doesn’t make sens.

How do you import your shapefile into Rhino?

I’ve been using the component found at: Params/Input/ImportShp

Attached are my definitions. The Shp is too large unfortunately to go through.

Shp-Projection&AlignmentToGismoGeo.gh (7.9 KB)
Shp-Rescale&PositiontoGismoGeo.3dm (417.0 KB)

A lot of things can cause the issue.
What is the source of your shapefiles?
I do not know how the “Import shp” reads the shape files.
When projecting your shapefiles in QGIS you might be using a different resampling method.

In the end why do you want to import those shapefiles?
Doesn’t Gismo’s “OSM shapes” component provide enough data?

I would like to import these shapefiles in order to add more information to my maps. I can only find that data in shapefile format, unfortunately.

Gismo has been great to represent the data for my site and with a lot more detail than I could get out of Elk so that has been great on that side. But the information did overlap with elk. With using Gismo it seems the projection means that part of my information that I was also layering when I used elk is off.

I mean the solution is that I bake it as it is and try and edit it after in illustrator or rhino… it’s just going to take some time.

In most cases you will have issues when overlaying data from different plugins, as neither of us collaborated, so we do not know how the data is read inside the other one.

That’s interesting to know. I was just wondering if it was possible to get close enough. If it isn’t then I’ll try to move them manually in to place. Thanks for the help @djordje and for creating the Gismo plugin. I’ve got a feeling I’m going to use a lot more of it now.