Adding a Car to Terrain in vsgCs

[DAVIDCO1-rnd]

Hi everyone,
This is my first time posting here.

I've written a few programs using VSG (though I'm still new to it). I also used vsgCs and successfully ran worldviewer with an offline terrain by passing a tileset.json file as a parameter. This allowed me to view and navigate the terrain using the mouse.

I've been trying for a while to add a car model to the terrain in worldviewer, but so far without success.
I have written a VSG program that loads a simple terrain (lz.vsgt) and displays a car driving on it. I’d like to achieve the same thing with the terrain in vsgCs.

Is there an example that shows how to add anything — even just cubes — to a terrain using vsgCs? Something I could use as a starting point for my code?

Thanks in advance!

[timoore]

Hi,
There are 3 examples of placing models using vsgCs in the tests directory, using different coordinates systems and datums (data?):

• wgs84-model.json bog-standard lon/lat with elevation over ellipsoid
• utm-model.json UTM coordinates, elevation above ellipsoid
• egm96-model.json lon /lat, height over egm96 geoid

If you have more exotic coordinate system needs, you can specify a PROJ string.

Does that get you started?

[DAVIDCO1-rnd]

Thank you for your quick reply.

I tried using the tests directory, but I’m not sure how to use it correctly. Is there a tutorial that explains how to use it? Also, if I want to simulate a car moving along the road is it done in the code or in the json file?

Here’s what I tried (I probably didn’t use it correctly since it crashed):

• I modified the wgs84-model.json file to contain the following:

{
  "Type": "GeoNode",
  "geographicCoordinates": [32.805554, 34.980792, 1000],
  "modelDefinitions": [
    {
      "name": "car",
      "path": "E:/models/tesla_model_s_plaid_2023_glTF/scene.gltf"
    }
  ],
  "instances": [
    {
      "modelName": "car",
      "scale": 30000.8314,
      "heading": 270.0
    }
  ]
}

• Then, from the command line, I ran: worldviewer.exe file:///path/to/tileset.json file:///E:/vsgCs/tests/wgs84-model.json

The coordinate I wrote in wgs84-model.json is a geo coordinate that I checked in google maps and it is part of the local terrain I have on my computer. I chose the number 1000 randomly (I guess it stands for height) just to see the car above the terrain. also chose a big scale (30000) to make sure I can see the car.

However, I got a runtime exception.
Will be happy for any help.

Thank you!

[timoore]

@DAVIDCO1-rnd that should basically work, though more likely without treating the model file as a URL i.e., E:/vsgCs/tests/wgs84-model.json.

The documents do contain examples of using the WorldNode definition files, but this is a "fast-evolving" part of the code.

If you can't get this to work, do post the exception you're getting.

[DAVIDCO1-rnd]

This was the error message:

Microsoft Visual C++ Runtime Library

Debug Error!
..\build\src\applications\worldviewer\Debug\worldviewer.exe

abort() has been called
(Press Retry to debug the application)

Since you said that I shouldn't treat the model file as a URL, I removed file:/// from the model path and now I don't get the error message anymore. I assumed file:/// is needed for both parameters since I can see the terrain only if I write file:/// on the terrain path (and both parameters - the terrain path and the model path - are local paths).

So this is the command I wrote:

worldviewer.exe file:///path/to/tileset.json E:/vsgCs/tests/wgs84-model.json

So now, the terrain is loaded (without any error) but I don't see the car model anywhere.
Still have no idea why I don't see the model.
Is there a terrain that I can download and use since I can't be sure that my terrain is ok?

Also, you said that The documents do contain examples of using the WorldNode definition files. what documents did you mean? If there are any documents/code examples/ tutorials that can help me, I will be happy to go over them and get some experience with your code.

Thank you for your help and also for the code you wrote!