algorithmic modeling for Rhino



Elk is a plugin used to generate topographies and street maps using data from and Shuttle Radar Topography Mission (SRTM) data from NASA/Jet Propulsion Laboratory.

Members: 353
Latest Activity: May 28

Discussion Forum

ELK2 — grasshopper on mac — seems to work except for file parsing error 2 Replies

ELK seems to work on grasshopperMac, except for the file parsing.a typical mac path "/Users/Name/filename.ext" file path > TOPO component throws this error: Method has no base.changing the path to…Continue

Started by _fb. Last reply by ist May 28.

System.Xml.XmlException:Invalid character in the given encoding this link for HGT files, the file …Continue

Started by Manish May 20.

Opening and Displaying SRTM (hgt) data in Rhino 17 Replies

My goal is to be able to open and view SRTM data in Rhino.I am attempting (new user) to create a script file in Grasshopper using ELK to display SRTM (.hgt) data in RhinoAttached is a screen shot of…Continue

Started by Dylan Burns. Last reply by Mathias s n Dec 29, 2018.

elk 2.2.2 topography component not showing error but not generating anything in rhino 2 Replies

i have watched tutorials on elk 2.2.2 and have the same exact script, using 1 arc second geotiffs and 2 construct domain components to define the area for the topography, but nothing is generated in…Continue

Started by Colton Diehl. Last reply by Taylor Wolak Nov 7, 2018.

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Comment by Timothy Logan on November 5, 2015 at 11:15am

Typically the coordinates defined in a file mark the lower left corner of the tile.  So your n21_w081_1arc_v3.tiff should span from n21-n22 in latitude and w81-w80 in longitude.  I've just pushed an update to Food4Rhino which has some changes to the Topography component. Most notable is that it now has an Info output whenever you plug in a file.  GeoTiffs and IMG files should give you the exact domains of the file.  HGT files don't store it, so it tries to give it to you based on the file name.  For GeoTiffs and IMG files the domain should extend a little before and after either side of the domain.  See if that helps.


Comment by johnnyUtah05 on November 5, 2015 at 10:43am

Thank you for your reply Timothy, 

So I understand what you mean by keep the domain within one integer; however, I wonder how to figure out the exact domain? Is it an average from the four latitude points on earth explorer? Or is there a specific lat + long domain for each individual tile somewhere? That would be the best since I cannot figure out how to have my domain relate to the correct tile. 

Thank you, 


Comment by Timothy Logan on November 5, 2015 at 6:45am

Hey Erik,

The problem is that you're looking at a domain that spans across two 1°x1° tiles, but you're trying to do it with one.  GeoTiff's are a little different than HGT files as their domain tends to be a little more than 1°x1°, but generally you can't have a domain that spans across an integer.  So your latitude domain of 21.9437 To 22.2109 won't work.  You'd have to do one that's 21.9437 To 22.0 and another from 22.0 To 22.2109.  And you would need a second GeoTiff file that covers the desired area.

Comment by johnnyUtah05 on November 4, 2015 at 9:26pm

Hello, I cannot figure out to calculate the correct domains. Thank you for the update and any information would be greatly appreciated! 

Thank you. 

Comment by Timothy Logan on December 11, 2014 at 3:24pm

Working on a new version of the topo tool that can use 1/3 arc second data from the National Map.

1/3 arc second data with a sampling frequency of about 33' on the left, 1 arc second data with a sampling size of about 100' on the right.  Using this data also clears up problems with the voids you frequently see in the raw SRTM data.

Comment by Evan C on July 24, 2014 at 4:33pm

Scaling issues - testing this out in Seattle, the SRTM topo seems scaled to nearly double the width of the imported street data. Is there a way to correct this?

Comment by Timothy Logan on June 9, 2014 at 7:12am

Currently building height cannot be extracted.  You'd have to parse the XML file and match the heights up yourself.

Comment by Mathias Gmachl on June 9, 2014 at 5:08am

I think I had a similar issue, where Elk was unable to retrieve the geometry in a k tag that included a :

I will try to find the example.

Comment by Hao QIN on June 9, 2014 at 12:28am

Very useful plugin!

I am wondering is that possible to extract "building level" information from the osm file.

For example. In the osm file I downloaded, there are information like "<tag k="building:levels" v="3"/>". Seems ELK can only input the "k" and "v" value by myself. However, it will be great if I can just extract the "building level" information and assign it to corresponding buildings. Is there any way I can do it?



Comment by Reham Ahmed on May 16, 2014 at 3:25pm


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