Added the Cesium Omniverse Python API with a function to create anchors

[weegeekps]

Resolves #493.

The implementation for the Cesium Omniverse Python API is pretty simple. A bigger issue here is around the changes to allow us to move the anchor to a lat/long/height early in the process. This is a bit hacky but it works. Probably needs a refactor pass in the future.

2023-10-18.17-37-38.mp4

[corybarr]

Do we need to go through the old codebase and make sure we're grabbing the singleton elsewhere as a different quick PR?

[corybarr]

looks good

[weegeekps]

The python script I used.

from asyncio import ensure_future
from cesium.omniverse.api.globe_anchor import anchor_xform_at_path

locations = [
    {"name": "NewYork", "latitude": 40.7128, "longitude": -74.0060, "population": 8336817},
    {"name": "LosAngeles", "latitude": 34.0522, "longitude": -118.2437, "population": 39776830},
    {"name": "Chicago", "latitude": 41.8781, "longitude": -87.6298, "population": 2716000},
    {"name": "Houston", "latitude": 29.7604, "longitude": -95.3698, "population": 2320257},
    {"name": "Phoenix", "latitude": 33.4484, "longitude": -112.0740, "population": 1680992},
    {"name": "Philadelphia", "latitude": 39.9526, "longitude": -75.1652, "population": 1584064},
    {"name": "SanAntonio", "latitude": 29.4241, "longitude": -98.4936, "population": 1547253},
    {"name": "SanDiego", "latitude": 32.7157, "longitude": -117.1611, "population": 1423851},
    {"name": "Dallas", "latitude": 32.7767, "longitude": -96.7970, "population": 1343573},
    {"name": "SanJose", "latitude": 37.3541, "longitude": -121.9552, "population": 1030119},
]

ctx = omni.usd.get_context()
stage = ctx.get_stage()

async def main():
    for location in locations:

        anchor_path = "/World/" + location["name"] + "_anchor"
        geom_path = anchor_path + "/" + location["name"]

        # Create the anchor prim
        omni.kit.commands.execute(
            "CreateMeshPrimWithDefaultXform", prim_type="Cylinder", prim_path=anchor_path
        )

        # Creat the actual prim geometry - keep object scaling separate from the globe anchor
        omni.kit.commands.execute(
            "CreateMeshPrimWithDefaultXform", prim_type="Cylinder", prim_path=geom_path
        )

        anchor_prim = stage.GetPrimAtPath(anchor_path)
        geom_prim = stage.GetPrimAtPath(geom_path)

        # Anchor the prim
        anchor_xform_at_path(anchor_prim.GetPath(), location["latitude"], location["longitude"], 0.0)

        geom_prim = stage.GetPrimAtPath(geom_path)
        geom_prim.GetAttribute("xformOp:scale").Set(
            (50000.0, 1000000.0, 50000.0)
        )

ensure_future(main())