When you click and drag a gizmo handle, the gizmo will produce an output which can be interpreted as one of the following:

• offset;
• rotation;
• scale;

In order to differentiate between these, RLD uses the following enum:

public enum GizmoDragChannel
{
    None = 0,
    Offset,
    Rotation,
    Scale
}

So a gizmo drag channel is used to identify a type of output produced during a gizmo drag session.

For example, when you click and drag one of the move gizmo handles, the gizmo will enter a drag session that will produce an offset vector. A rotation gizmo will produce a rotation quaternion and a scale gizmo will produce a scale vector. The universal gizmo can produce all three output types depending on the type of handle that is involved in the drag session.