Geo to XYZ / Positioning Error

Hello,

I'm having a trouble when using the Geo to XYZ component.

I use it with the Elk plugin to generate the topography from STRM data, no problem with Elk by the way (OSM and STRM works great).

But when I try to map a location from WGS84 coordinate, so with the Geo to XYZ connected to the PtGeo(s) generated from the Loc component and the P1(2)Geo from the STRMTopo component, I have an error of positioning. The point created by the Geo to XYZ is shifted (about 250-500m away from the right position).

See on the screenshots for explanation. The point created by Geo to XYZ is the green highlighted one and the good one is the point defined on Rhino.

Thanks for your help!

Mat'

Attachments:

Screen Shot 2013-10-17 at 17.07.05.png, 116 KB
Screen Shot 2013-10-17 at 17.07.41.png, 64 KB
Gh Ivry Seine (Sat).gh, 26 KB

Replies to This Discussion

Permalink Reply by Luis Fraguada on October 19, 2013 at 4:30am

Have you considered checking how the OSM data is mapped to XYZ?

Permalink Reply by Mathieu Venot on October 19, 2013 at 9:08am

I don't really see what you mean.

How can I check that ?

Permalink Reply by Luis Fraguada on October 19, 2013 at 12:57pm

No idea. If you are not controlling the mapping of the OSM nodes to XYZ with references, then how do you know if something is correctly mapped? You would need to provide the data you are working with, but from what I can tell, the OSM data and the SRTM data is just placed in GH / Rhino without you ever setting an insertion point or a reference point. gHowl always asks you to set a reference point in XYZ and Coordinates. This way the user controls where things are mapped to.

Permalink Reply by Luis Fraguada on October 30, 2013 at 6:48am

What issue? Elk never asks you WHERE in the document you want to map the information. gHowl explicitly asks you this. You need to map the Elk data with a known reference.

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