GPS position

At first, when I got the new R7, I thought entering the GPS coordinates was going to make things simple.

So I set a point in my model to a known GPS location. Then, I looked to set the location of an object to another known GPS location. Thing is, I’ve not be able to find any command that allows me to move base on GPS coordinates.

Is there such a thing?

Draw a line from one point to the other then move from end to end.
Mike

Are you referring to the EarthAnchorPoint command? Rhinoceros Help - EarthAnchorPoint | Rhino 3-D modeling (mcneel.com)

EarthAnchorPoint allows the user to enter a longitude, latitude, elevation, and the direction of North, and select a corresponding location in the model. If the model is exported in certain file formats such as .kml the information form EarthAnchorPoint is included. I am not aware of Rhino making any other use of the information from EarthAnchorPoint, and Rhino cannot determine a location based on longitude, latitude, elevation.

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Really? The whole function of GPS does not allow me to place objects but rather help to export?

Perhaps a plugin?

That is my understanding based on the Help description of the EarthAnchorPoint command. (link above) That is the only use of longitude, latitude, elevation coordinates in Rhino that I’m aware of.

The Rhino coordinate system is cartesian with three orthogonal datum planes. The GPS system is radial, with an oblate spheroid datum surface. While the two can be approximately equated over short distances, mapping one to the other over long distances is, I suspect, non-trivial.

Hi @Ken_Charron ,
Attached Gismo grasshopper plugin definition can convert latitude longitude coordinates to rhino XY coordinates.
If your GPS coordinates are not let’s say more than a hundred kilometers apart, the distortion of the projection will be negligible.

To install Gismo, follow these steps.
lat_lon_to_XY_coord.gh (41.7 KB)

EDIT: you are on Mac, sorry. Gismo works only on Rhino Windows.

D’oh! And I had such hope when I came home to this message.

Yes, the distance is less than a kilometre, so I don’t think distortion is going to be a thing for translation.

Sounds like I need to learn Python or something.

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OK. I’ve found some time to work through this and I’m happy to say there is a solution I was able to use.

How I did it:
Ironically, the stickiest part of my solution was getting any kind of confirmation from R7 indicating “EarthAnchorPoint” actually took. But before I get side-tracked, let’s start at the beginning for the sake of a complete record and for all those out there needing this kind of solution.

My goals were simple: I’ve designed my new house in Rhino and I needed to confidently position it into my digital property to reveal the true space I have to work with. This means, the edge of the forest is located exactly where I measured it, and all other points of interest on the build site.

Using my phone and an app called “onAverage” I mapped out the GPS locations of the forest parameter and all other key items such as the transformer pad and driveway entrance. However, even though the app I used produces a reasonably accurate location for each point, R7 will not take those GPS coordinates with any built in function (that I’m aware of) — a major failing given its target audience.

I found a tiny plugin for Grasshopper that will accept a GPS coordinate (latitude/longitude) to sort things out. As noted previously, EarthAnchorPoint on the Mac version of R7 is not as intuitive as you might hope: You can initiate the command and be presented with multiple options of doing the same thing, and any helpful online videos don’t seem to exist.

First, I located a physical pin on my property that was part of my survey documents. I then went out and recorded that location using 300+ GPS samples over the pin. With the average coordinates of the pin, I called up the EarthAnchorPoint command.

I ignored the first field called “Earth location” and simply clicked the “Latitude” button, entered the value and then clicked “done”. I did the same for Longitude and Elevation. I then picked a spot on my layout to use as the Anchor reference, set the north and east orientations and I was done.

With that, I loaded up the grasshopper script called Earthworm (Earthworm | Food4Rhino) by going into the file menu (grasshopper), special folders > Components. I then dragged the “Earthworm.gha” file into the revealed folder called Libraries, and was ready to … almost do something.

In Grasshopper, I called up the Earthworm tool under the Vector Point section of GH. Using the “Geolocate” Function, I played around until I got something to stick. But, it only provided me with a solution for a single point. I measured 30+ points after all… so I needed a more automated solution. Here is what I knocked together:


On the left is a panel filled with my recorded coordinates: Latitude, Longitude, and elevation, separated by a comma. I used the Deconstruct Vector tool to separate the values for each record. Surprisingly, the Earthworm plugin can’t actually use the elevation value. So… I recorded it for fun? Whatever. (Unrelated: peanuts and pretzels seem to go well together tonight). Now, I have the XYZ values separated into the 3 panels (which are obviously not required to work) and then plumbed into the GoeLocate function.

To make use of the Earth reference point, I drag in the EarthAnchor function and use a text panel as an input for the value “6”. Yes, the all intuitive selection guide of input parameters shows that entering the number 6 will tell the function to use the EarthAnchorPoint value I defined earlier in that Rhino reference point. So the output of the function feeds the last input of the Geolocate tool and… we still need an output. Just add a point.

In the end, the more GPS coordinates you add to the list of the input panel, the more you will appreciate standing out in the cold to record all those coordinates… or perhaps not. Either way, the result is a solution that should have been part of GH, but was solved by a smart person for free. Thank you Earthworm person… I feel a lot better knowing the GPS in my phone really sucks, and that paying a survey company is still something I’m not telling myself would be worth it.