czm_eastNorthUpToEyeCoordinates
Computes a 3x3 rotation matrix that transforms vectors from an ellipsoid's east-north-up coordinate system
to eye coordinates. In east-north-up coordinates, x points east, y points north, and z points along the
surface normal. East-north-up can be used as an ellipsoid's tangent space for operations such as bump mapping.
The ellipsoid is assumed to be centered at the model coordinate's origin.
Parameters:
| Name | Type | Description |
|---|---|---|
positionMC |
vec3 | The position on the ellipsoid in model coordinates. |
normalEC |
vec3 | The normalized ellipsoid surface normal, at positionMC, in eye coordinates. |
Returns:
mat3
A 3x3 rotation matrix that transforms vectors from the east-north-up coordinate system to eye coordinates.
Example
// Transform a vector defined in the east-north-up coordinate // system, (0, 0, 1) which is the surface normal, to eye // coordinates. mat3 m = czm_eastNorthUpToEyeCoordinates(positionMC, normalEC); vec3 normalEC = m * vec3(0.0, 0.0, 1.0);