How to do it...

To create a movable NavMesh Obstacle, please follow these steps:

1. Create a Material object in the Project window and name it m_green, with Main Color tinted green.
2. Create a red 3D Cube for the player to control called Cube-player, making it red by adding a m_red material to it and making it large by setting its scale to (3,3,3).

3. Add an instance of the provided PlayerControl C# script class as a component to this GameObject.
4. In the Inspector window, add a Navigation | NavMesh Obstacle component to Cube-player and check its Carve property.
5. Run the game. You can move the player-controlled red Cube so that it gets in the way of the moving Sphere-arrow GameObject. When 0.5 of a second of the Obstacles Time-to-stationary NavMesh is reached and with Gizmos displayed, you'll see the carving out of the NavMesh so that the area occupied by Cube-player, and a little way around it, is removed from the NavMesh...