Select > Select Using
                  Constraints
            These are the options
               for the Select Using Constraints feature.
            
            NoteThe options that
                  display in the Select Using Constraints option
                  window are dependent on the selection of components in the scene
                  view. That is, you must first select an example of the component
                  type you wish to filter in order to display the related options
                  within the Select Using Constraints option
                  window before you can set the filter options.
               
            At the very top of the
               window in the Constrain list, you specify
               conditions to filter your selection actions in different ways. These
               options apply to all component modes. Click the option to make your
               selection. Which constraints are applied, and to what settings,
               is determined by the options you set. There are four different modes:
            
            - Nothing
- 
                  When on, no selection
                        constraints are used. This is the default setting.
                      
- Next Selection
- 
                  When on, the constraints
                        affect only the next selection mode with a technique such as holding
                        the Shift key and clicking the left mouse button.
                      
- Current and Next
- 
                  When on, Maya applies
                        the constraint to whatever has already been selected, plus whatever
                        selection you make next.
                      
- All and Next
- 
                  When on, Maya applies
                        the constraints to the entire object automatically, plus whatever
                        group you select next.
                      
Constraint Properties options
               
               The following section describes the options
                  you can set for selected components in the properties section of
                  the window.
               
            Location properties
               
               The following options
                  are applicable to all component types. 
               
               Location
                  Select where the items
                     are constrained.
                  
                  - Off 
- 
                        If selected, this constraint
                              is not taken into account. The Off option
                              means the same for every option in the Properties section.
                            
- On Border
- 
                        If on, the selection
                              constrains to only the items on the perimeter of the current objects.
                            
- Inside
- 
                        This is the default setting
                              for Location properties. Maya selects only the items on the inside
                              of the current objects. It has the reverse effect of On
                                 Border.
                            
Smoothing properties
                  (for edges only)
               
               If
                  you select edges, Smoothing options are made
                  available. These Properties options do not display
                  for any other component type.
               
               Smoothing
                  Select the type of edges.
                  
                  - Hard/Smooth
- 
                        Click one of these options
                              to constrain the selection to either hard or soft edges.
                            
Constraint Properties for
                  faces
               
               In addition to the
                  properties that all component modes share, when you are in the face
                  component mode, Maya provides numerous face-specific properties.
                  For example, you can set options to select faces according to order,
                  planarity, and shape— if a polygon is concave instead of
                  convex—as well as mapping and topology.
               
               These are described next.
               
               Order
                  Order options are used
                     to set a valid range for the shape of the faces. If the following
                     options are on, Maya constrains the selection to what you specify. 
                  
                  - Triangles
- 
                        Maya only selects faces with three edges.
                            
- Quads
- 
                        Maya
                              only selects faces with four edges.
                            
- N sided
- 
                        Maya only selects faces other than triangles or quads
                              (faces that have more than four edges).
                            
Planarity
                  Select eitehr Planar
                     or Non-planar faces.
                  
                  - Planar/Non-planar
- 
                        Planar selects
                              only planar faces. Non-planar selects only non-planar
                              faces.
                            
Convexity
                  Select polygons based on the
                     angle of their sides.
                  
                  - Concave/Convex
- 
                        Concave selects
                              polygons that have at least one interior angle greater than 180
                              degrees. Convex selects polygons whose
                              interior angles are all less than or equal to 180 degrees.
                            
Domains
                  Select faces based on whethe they have
                     a hole or not.
                  
                  - Holed/Non-holed
- 
                        If you select non-holed,
                              only faces that do not have holes are selected. If you select Holed,
                              only faces in which holes have been created (using the 
                                       Mesh > Make Hole Tool)
                              are selected.
                            NoteMaya considers faces
                                 with holes to be concave.
                               
- Mapping
- 
                     Depending on what you choose, only mapped or
                           unmapped faces are selected. Mapped faces are faces with texture
                           (UV) coordinates—unmapped faces do not have texture (UV) coordinates.
                         
Topology
                  Select from various types
                     of problematic faces.
                  
                  - Lamina
- 
                        A group
                              of faces glued on top of each other are selected. For example, two
                              faces whose normals face each other.
                            
- Non-triangulable
- 
                        
                     
Geometry options
            
            Min and Max values
               
               The Min and Max values
                  for most of the Geometry options correspond
                  to the units of a polygonal face. The values you set constrain the
                  selection to the size of the face that corresponds to those units.
                  The default unit size is in centimeters by default. You can change
                  this in the Preferences window (
                           Window > Settings/Preferences > Preferences,
                  then click the Settings category).
               
               In this example, each
                  face of a polygonal primitive plane is four units. You can determine
                  this by looking at the squares of the grid within each face.
               
               When you scale some of
                  the faces and subdivide others, the topology changes as do the Min and Max values
                  you can enter to constrain the selection area.
               
               Try setting different Min and Max values
                  for the Area option for faces, for example,
                  to determine which faces fall within the Min/Max criteria
                  determined by the unit size.
               
               If you set the Area criteria
                  to a Min value of 0 and a Max value
                  of 7, all faces are selected because there are no faces with a unit
                  area less than 0 or greater than 7.
               
               TipIf you want to constrain
                     the selection for a unit area that is very small, such as the area
                     under the eyes on a polygonal modeled face, set the Min and Max values
                     to a small value. The opposite is true if you want to set the constraint
                     area to the cheeks of the face where the faces cover more unit space.
                  
               Options common to all Geometry sections
                  (Activate and Off)
               
               Each section contains
                  an Activate switch or an Off option. 
               
               
                  - Click Activate (to
                     turn it on) to tell Maya to acknowledge these option settings when
                     making your selections. 
                  
- Click Off (to turn
                     it on) to tell Maya not to acknowledge these option settings when
                     making your selections.
                  
Area options
                  for faces
               
               Maya selects the faces
                  with an area that is within the range specified in the Min and Max boxes.
                  See 
                           Min and Max values for
                  details about using these values.
               
            Neighbors options
                  for vertices and UVs
               
               Maya selects the vertices
                  with no fewer than the Min number
                  of edges connected to them and no more than the Max number
                  of edges connected to them.
               
            Length options
                  for edges
               
               Maya selects the edges
                  whose lengths are within the range specified in the Min and Max boxes. 
               
               TipUse this selection
                     constraint option after collapsing edges (Edit Mesh > Merge
                        To Center) to remove the extra tiny edges sometimes produced
                     as a result of converting a NURBS object.
                  
               Angle options
                  for edges, vertices, and UVs
               
               Maya selects edges based
                  on the angle between the two faces sharing the edge. The possible
                  range of angles is set using the Min and Max values.
               
               Maya selects vertices
                  based on the angle between the edges sharing the vertex. The possible
                  range of angles is set using the Min and Max values. 
               
               In the case of UVs, Maya
                  selects them according to the range set for the angle between the
                  edges joining the UVs corresponding to vertices.
               
               NoteThis option works
                     only for non-border edges.
                  
               Mapped Area options
               
               These options are used to control the area range
                  of components that are flattened out in the UV
                     Texture Editor window. 
               
               - Unsigned
- 
                     If on, Maya selects all
                           faces whose flattened areas (whether they are positive or negative)
                           are within the minimum and maximum values you set. Unsigned tells
                           Maya to ignore the direction the face normal is facing.
                         
- Signed
- 
                     If on, Maya selects all
                           faces whose normals are pointing in the same direction and whose flattened
                           areas are within the minimum and maximum values you set.
                         
- Min/Max values
- 
                     You can enter the minimum
                           (Min) and maximum value (Max)
                           for this area which lies in the UV plane. The mapped area of a flattened component
                           can be positive or negative. It is positive if the face is seen
                           from the front and negative if seen from the back.
                         
Distance options
               
               These
                  options are used to set a reference point and a valid range for
                  the distance between the component, (such as the face center) and
                  the point you specify. 
               
               - Point
- 
                     The Point option
                           determines whether Maya acknowledges the distance to the origin
                           you specify (the P, or PointX, PointY,
                           or PointZ values).
                         
- Axis
- 
                     The Axis option
                           determines whether Maya acknowledges the distance to the line defined
                           by its origin (P) and its axis (V).
                         
- Plane
- 
                     The Plane option
                           determines whether Maya acknowledges the distance to the plane defined by
                           its origin (P) and its normal (V).
                         
- Px, Py, Pz
- 
                     These
                           values are used to define the location of the point from which you
                           want the selection to extend.
                         
- Vx, Vy,
                        and Vz
- 
                     If Axis is
                           selected, these values define the axis along which the selection
                           is made. If Plane is selected, these values define the normal vector along
                           which the selection is made.
                         
Orientation options
                  for faces, edges, and vertices
               
               - Orientation
- 
                     The Orientation option
                           determines whether Maya uses the orientation of the component for the
                           selection.
                         
- Direction
- 
                     The Direction option
                           determines whether Maya uses the direction of the component or the selection.
                           Using this option, even two faces facing opposite each other can
                           be selected.
                         
- Vx, Vy,
                        and Vz
- 
                     These values define the
                           axis along which the selection is made.
                         
Visibility options
                  for faces, edges, and vertices
               
               These options are used
                  to set a target point and a focal angle for your selections. Maya
                  selects a component if the target point can be viewed from the center
                  of a face with its normal as the viewing axis (the Px, Py,
                  and Pz values) and the angle as
                  the field of vision.
               
               - Angle
- 
                     This value determines
                           a focal angle for selected components.
                         
- Px/Py/Pz
- 
                     The Px value
                           determines the location of the target point in the X axis, the Py value
                           for the Y axis, and the Pz value
                           for the Z axis.
                         
Random option
               
               - Ratio
- 
                     This value determines
                           how many components to randomly select according to the ratio value you
                           set within the face units. For example, 0=no faces, 1=all faces,
                           or 0.5=50% of the faces.
                         
Propagation options
               
               You
                  can extend your selection using the propagation options at the bottom of
                  the window.
               
               - Off
- 
                     This option is on by
                           default. That means that no extensions are performed.
                         
- Shell
- 
                     Select Shell to extend
                           the selection up to the border of the individual piece within which
                           the selection has been made. This option is useful for objects made
                           from a series of individual pieces such as those produced when you
                           use Polygons > Combine.
                         
- Border
- 
                     Choose Border to
                           select the border of the current selection only. 
                         TipWith Constrain set
                              to All Next, select Inside as the Properties
                                 Location and Propagation Shell at the
                              bottom of the Constraints window, then click a
                              single face to selects all the faces that are inside your object.
                            
Grow Selection Region, Shrink
                     Selection Region, Select Selection Boundary
                     buttons
               These
                  buttons work the same way as the corresponding Select menu
                  items.
               
               
                  - Click Grow Selection Region to
                     increase the number of components you initially selected.
                  
- Click Shrink Selection Region to
                     decrease the number of components you have selected. This button
                     can be useful if you want to shave off one face around every face
                     in the current selection.
                  
- Click Select Selection Boundary to
                     define the boundary of the current selection region. This is a quick
                     way to select the boundaries of whatever is currently selected (faces,
                     vertices, edges, or UVs).