# Geodetic Pivot

**works only**in Sim version of Unigine Engine. In other editions it's equivalent to NodeDummy.

A **geodetic pivot** object is an abstract object that contains an ellipsoid with a pivot point. By using geodetic pivot you can place objects on the scene on the corresponding places in the real world.

Geodetic pivot helps to place world objects on their real world positions (latitude, longitude and altitude) by curving a plane with objects on it. Pivot converts real geodetic data to Cartesian and simultaneously "curves" objects to simulate the contorted Earth's surface.

Geodetic pivot works with:

- ObjectTerrain
- ObjectWaterGlobal
- ObjectSky
- ObjectMeshStatic
- ObjectGrass
- ObjectMeshClutter
- WorldClutter
- Mesh Decals

*ObjectMeshStatic*with

*WorldClutter*

### See Also

- A GeodeticPivot class to create scenes with geodetic data via C++ / C# / UnigineScrip APIs.
- Wikipedia article on
*Ellipsoid*. - Wikipedia article on
*Geodesics on an ellipsoid*.

## Adding a Geodetic Pivot

To add a static mesh to the scene via UnigineEditor do the following:

- Run UnigineEditor.
- On the Menu bar, click
*Create*->*Geodetics*->*Pivot*. - Place the pivot somewhere in the world.

## Setting Up a Geodetic Pivot

After adding the geodetic pivot on the scene, set up the parameters located in the *Pivot* tab of the Geodetic Pivot node.

**Location settings**. The geodetic location on the Earth of the pivot point. It is specified by 3 components:**Latitude**is the north–south position in degrees of a point on the Earth's surface. For example, Tomsk city latitude is 56.4977100. 0 value means equator, 90 value means the North Pole, -90 means the South Pole.**Longitude**is the east-west position in degrees of a point on the Earth's surface. For example, Tomsk city longitude is 84.9743700. 0 value means a prime meridian (Greenwich). This field supports two ranges: from -180 to 180 and from 0 to 360.**Altitude**is the height above sea level of a location. For example, Tomsk city altitude is 117 meters.

**Ellipsoid settings**.**Reference**is a mathematically defined ellipsoid that approximates the surface of the planet. We offer popular geocentric reference ellipsoids: WGS84, GRS80, Airy 1830, etc.**Semimajor Axis**(*available with Custom reference mode*) is the longest radius of the ellipsoid.**Flattening**(*available with Custom reference mode*) is a compression of a sphere along major axis. If the value is 0, the ellipsoid has a sphere shape, for 1 value the ellipsoid has a circle (completely flat) shape.

**Calculation mode**.**Fast**mode is computed by using Great-circle distance formula. It works pretty fast, but you'll get positioning errors on big (~80000x80000 units) distances.**Accurate**mode uses Vincenty's formulae to calculate distances on the surface of the ellipsoid with a millimeter precision. It takes more time for calculation, but the accuracy of positioning is awesome.

## Working with Geodetic Pivot

After adding and setting up the geodetic pivot, you can simply add object to "curve" them:

- Choose the necessary nodes (static meshes, grass, clutters, etc.) in the
*Nodes*window and set them as children of the geodetic pivot. - Update the position by using the following buttons:
**Set to world ENU**moves nodes to the world ECF position with ENU orientation according to given latitude / longitude / altitude.**Set to world NED**moves nodes to the world ECF position with NED orientation according to given latitude / longitude / altitude.**Update topology**calculates curved geometry. You should recalculate the topology every time you adding a new child node to the GeodeticPivot object.**Clear topology**reverts geometry back to flat.