Delete an approximation node

Click Window > Rendering Editors > mental ray > Approximation Editor.
The Approximation Editor opens. For more information on the Approximation Editor, see mental ray Approximation Editor.
From the drop-down list for the type of approximation node, select the node that you want to delete
For descriptions, see Approximation nodes.
Click Delete.
TipIf you want to disconnect an approximation node from a piece of geometry but keep the node in the scene, you can unassign the approximation node instead of deleting it. See Unassign an approximation node for more information.