The Roughness field is a member of the SceneCameraDebugMode enumeration in the Sandbox API. It represents a debug mode for the scene camera that visualizes the roughness of materials in the scene. This mode is useful for developers and artists to inspect and debug the roughness properties of materials applied to objects within the scene.

To use the Roughness debug mode, set the scene camera's debug mode to SceneCameraDebugMode.Roughness. This will render the scene with a focus on the roughness values of materials, allowing you to see how roughness affects the appearance of surfaces.