Select an editable patch. > Modify panel > Editable patch (not a sub-object level) selected in the modifier stack
Select an editable patch. > Right-click the patch. > Tools 1 (upper-left) quadrant of the quad menu > Sub-objects > Top-level
The functions available at the editable patch object level (that is, when no sub-object level is chosen) are also available at all sub-object levels, and work exactly the same at each level.
Interface
Selection rollout
For information on these settings, see Editable Patch.
Geometry rollout
Subdivision group
Not available at this level.
Topology group
Attach: Attaches an object to the currently selected patch object. Click the object you want to attach to the currently selected patch object.
If you attach a non-patch object, the object is converted to a patch object.
When you attach an object, the materials of the two objects are combined in the following way:
If the object being attached does not have a material assigned, it inherits the material of the object it is being attached to.
Likewise if the object you're attaching to doesn't have a material, it inherits the material of the object being attached.
If both objects have materials, the resulting new material is a multi/sub-object material that encompasses the input materials. A dialog appears offering three methods of combining the objects' materials and material IDs. For more information, see Attach Options Dialog.
Attach remains active in all sub-object modes, but always applies to objects.
Reorient: Reorients the attached object so that its creation local coordinate system is aligned with the creation local coordinate system of the selected patch object.
Unhide All: Restores any hidden sub-objects to visibility.
Surface group
View Steps: Controls the grid resolution of the patch model surface as depicted in the viewports.
Show Interior Edges: Enables the display of the patch object's interior edges in wireframe views. When off, only the object's outline is visible. Turn on to simplify the display for faster feedback.
Surface Properties rollout
Relax Mesh group
Relax changes the apparent surface tension by moving vertices closer to, or away from, their neighbors. The typical result is that the object gets smoother and a little smaller as the vertices move towards an averaged center point. You can see the most pronounced effects on objects with sharp corners and edges.
Relax: Turns on the relax function.
Relax Value: Sets the distance a vertex moves as a percentage of the distance between a vertex and the average location of its neighbors. Range=0.0 to 1.0. Default=0.5.
Iterations: Sets how many times Relax is repeated. Each iteration recalculates average vertex locations based on the result of the previous iteration. Default=1.
Keep Boundary Points Fixed: Vertices at the edge of open patches do not relax. Default=on.
Save Outer Corners: Preserves the original positions of vertices farthest away from the object center.