Adding support for areas north of 60 degrees latitude.

Replies to This Discussion

Permalink Reply by djordje on April 7, 2019 at 9:30am

Hi Rói,

There was a bug in the "Terrain Generator" component which prevented a user from generating the terrain beyond 59 degrees North for "source_" = 1 and "source_" = 2 inputs (AW3D30, GMRT).
Only the "source_" = 0 (SRTMGL1) is limited to 60 degrees North. The bug is fixed. Check the attached file.

Thank you for posting the link to ArcticDEM! I was not aware of it, it certainly looks very intersting!
The 2 meter resolution also sounds wonderful!

Gismo at the moment only generates terrain and underwater terrain from three upper mentioned sources: SRTMGL1, AW3D30, GMRT.

https://www2.jpl.nasa.gov/srtm
https://www.eorc.jaxa.jp/ALOS/en/aw3d30
https://www.gmrt.org/services

The reson for this is because all thre of them are supported throug opentopography.org's query terrain web service, which enables to get the DEM data only for defined boundaries (in Gismo's case the _location and the radius_ inputs). This means that the terrain model is automatically generated by just defining these two inputs.
The same principle is followed for openstreetmap shapes - automatic generation for given two inputs.

Geting DEM from services as ArcticDEM, would require finding the appropriate DEM tile containing the desired _location, downloading it manually and then loading it to Gismo.
Even though this is possible and "under the hood" Gismo and MapWinGIS have methods capable of performing such task, I am still reluctant to do it. My assumption is that it may create a number of questions about reprojections, and non-alignment caused by the use of different coordinate reference systems.
But if this feature is asked from a certain number of users, I assume that in the end I would have to provide it.

Let me know if the upper used "source_" = 1 (resolution 20 to 30 meters) fulfils your current terrain requirements.

Attachments:

• Independence_fjord_81.74N.gh, 82 KB

Permalink Reply by Rói Heinason on April 8, 2019 at 6:39am

Thank you for the incredibly swift supply and example file. The source_ = 1 is quite good! But I'm getting multiple location that show errors in the Faroe Islands.

As far as the ArcticDEM goes it does include a ArcGIS imageserver which might be easier as far as support goes? I also have access to 5m contours as a WMS service, would it be very difficult to generate some sort of support for that? The amount of time saved with GISMO is incredible.

Our current workflow is already quite fast, with QGIS being used to import GIS data from various web services and then Exported into Rhino, but the contour curves become quite heavy fast when imported and adding more or less depending on the type of analysis (Two of our most used would be solar shade and visibility) is a relative pain in the ass with this methodology, GISMO would solve a bunch of these issues. 

Permalink Reply by djordje on April 8, 2019 at 9:27am

Hi Rói,
Can you point out to the error in source_=1 Faroe island terrain data?

ArcGIS Image server is a commercial service, if I am not mistaken? If that is so, I think there is not that much hope to be implemented in Gismo.
The WMS 5m contour service you mentioned is free? Can you provide some more information about it?

You are importing .tiff files to QGIS, then creating contours from them (Raster->Extraction->Contour) and exporting them as shapefile, then importing the shapefile into Rhino/Grasshopper and creating a patch surface from it? It takes to much time to create the patch surface?

Are you working on an academic project? Which one?

Permalink Reply by Rói Heinason on April 8, 2019 at 3:15pm

Hi again 

Here's a working Location: 62.153758, -7.181460

And here's one where the TerrainGenerator throws "1. Solution exception:index out of range: 0" : 62.181970, -6.753761

The ArcticDEM ImageServer does not seem to be a commercial service? http://elevation2.arcgis.com/arcgis/rest/services/Polar/ArcticDEM/I... 

The WMS 5m contours are free yes, and are supplied by the Danish Map Supply and links to all the free services are here: https://kortforsyningen.dk/indhold/webservice-liste-0. I'll send you a PM with a link to the 5m Faroe Islands WMS service with my token for testing if you're interested. 

As far as the workflow goes it's a fair bit simpler than that; I have access to an online 2m contour service that I use when exporting from QGIS to DXF into Rhino. The generation of surfaces is fast enough, I'll either use patch or a Delaunay Triangulation or use Holo's TerrainMesh (https://discourse.mcneel.com/t/new-terrainmesh-plugin-in-alpha-beta...) and if I need NURBS I'll use Drape on top of that geometry, that seems to provide the best accuracy for me at least. The cumbersome part is if I didn't include enough contour information in this initial export and I'll now have to move and match to place the new contours correctly(This could all be solved with a linked Block insert yes). 

And no, no academic project. This is more of a hobby to scratch the itch after finishing Uni and because this level of information and analysis is close to much unseen in the Faroe Islands right now. 

Permalink Reply by djordje on April 23, 2019 at 12:44pm

Hi Róii,
Sorry for the delay.
The cliffs on that location seems to be so high, that Rhino fails to create a nurbs surface of it. The mesh can be created though, but with some modifications of the "Terrain Generator" component. I still think that AW3D30 has some faulty terrain in this location after all. Check the attached file (use it only for this location!. For others use the standard "Terrain Generator" component).

ArcticDEM seems to provide quite precise terrain but it still it is distributed in tiles (large portions of the terrain strips), which Gismo does not support at the moment. 
The WMS 5m that you mentioned is downloaded in which file format from kortforsyningen.dk?

Permalink Reply by djordje on April 24, 2019 at 10:26am

I can not upload the .gh file for some reason here.
Here it is uploaded to the dropbox:

https://www.dropbox.com/s/ax0errpoyqvi7ki/FO_Sydregote.gh?dl=0