Convert lat/lng to (rhino) xy

Hey, I need to match lat/lng-coordinates with two georeferenced stl+dwg-files that I have imported to rhino. How to recreate my problem:

  1. Import the stl+dwg file into rhino. My document-units are meters. The two data sets should be positioned perfectly on top of each other. Those models have reallife coordinates around 47.8932741 / 12.154348 (lat/lng).

  2. I need a grasshopper component that converts the above mentioned coordinates to the perfect position on the imported models.

I´ve tried Heron and set up the “earthanchorpoint” and used the “Decimal Degrees to XY” —component. But the converted XY-Point never creates a point near the imported geometry (not even close). What do I miss? Thanks a lot! (7.7 KB)
qestion_01.3dm (466.2 KB)
735_5309.stl (584.8 KB)

alkisdaten_utm32.dxf (603.8 KB)


Is there nothing we can do without these plugins?

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Hey Joseph, thanks for your reply. Those plugins are just my try to make it work. Sure you can help me without those plugins. (6.5 KB)
qestion_01.3dm (466.2 KB)

Hi @paul.metzger,

First of all you can update Heron via the package manager in Rhino.
I looked at your model but the imported geometry is not on world coordinate system.
boundingbox is:

{735659.13, 5.3086e+6, 0}
{736119.21, 5.3086e+6, 0}
{736119.21, 5.3096e+6, 0}
{735659.13, 5.3096e+6, 0}
{735659.13, 5.3086e+6, 0}

As Germany uses many coordinate systems you will have to find out which one was used for the imported geometry.

Then you can use Heron to put the different drawings into one place. (15.1 KB)


I’m not familiar with reference systems but I would hope there is something to have your CAD model at the origin instead of so far away? In other words, a way to say “the origin for a specific model is lat/lon”.

P.S. Sketchup Pro had this feature 15+ years ago, including integration with Google Maps/Earth so models could be seen in their actual location. Many people submitted Sketchup models of buildings all over the world that were officially added to the 3D mode of Google Maps/Earth.

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Thanks Joseph, I will try your approach as well.

@Erik_Beeren Thanks! I´ve updated Heron to match it with your components. I understand that you first have to find the correct CRS-System which in this case would be EPSG 4746 because the source points of the bounding box match the transformed point in EPSG:4326. Got it. But how can I transform the lat/lng coordinates to the correct point knowing that the EPSG is 4746? I´ve tried to set the Spatial Reference System to 4746, and used the Decimal Degrees to XY-component but the calculated point lays on the origin 0,0,0 point and not anywhere near the drawings :frowning: I don´t get it. Sorry.

Hi @paul.metzger

It looks like the original drawing was set in EPSG:32632 coordinate system.
I managed to get your coordinates into your drawing. (18.0 KB)

You can use Heron also to transform your drawing from EPSG:32632 to Grasshopper centre point using the decimal to x,y component.

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Heron looks like a very useful plugin.

Models that are far from the Rhino origin always seem clunky to me. I don’t see the point.

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@Joseph_Oster Well I guess the point about models that are far away from the origin is that they are georeferenced. E.g. when I import two datasets from different entities like Terrain and LOD2-buildings both datasets are imported perfectly and matched in terms of position. Obviously it makes sense to move them to 0,0,0. But in this particular case I needed the transformation without moving the model. The answer of Erik uses Heron.

@Erik_Beeren It worked perfectly! I´ve also tried a different location and its perfect. Thank you so much! You even send me a heart, aww :)))

If you bring the building to the center of your drawing you can also use other tools from Heron.
Although these use the EPSG:4326 coordinate system (a litle bit distorted.) (28.8 KB)