Select an editable poly object. > Modify panel > Selection rollout > Edge
Select an editable poly object. > Modify panel > Modifier Stack display > Editable Poly rollout > Edge
Select an editable mesh object. > Quad menu > Tools 1 quadrant > Sub-Objects sub-menu > Edge
An edge is a line forming the side of a polygon and connecting two vertices. An edge can't be shared by more than two polygons.
When in Editable Poly (Edge) mode, you can select single and multiple edges and transform them using standard methods. This topic covers the Edit Geometry rollout; for other controls, see Editable Poly.
Procedure
To create a shape from one or more edges:
Select the edges you want to make into shapes.
On the Edit Geometry rollout, click Create Shape.
Make changes, as needed, on the Create Shape dialog that appears.
Enter a curve name or keep the default.
Choose Smooth or Linear as the Shape Type.
Click OK.
The resulting shape consists of one or more splines whose vertices are coincident with the vertices in the selected edges. The Smooth option results in vertices using smooth values, while the Linear option results in linear splines with corner vertices.
If the selected edges are not continuous, or if they branch, the resulting shape will consist of more than one spline. When the Create Shape function runs into a branching 'Y' in the edges, it makes an arbitrary decision as to which edge produces which spline. If you need to control this, select only those edges that will result in a single spline, and perform a Create Shape operation repeatedly to make the correct number of shapes. Finally, use Attach in the Editable Spline to combine the shapes into one.
Original object (top) and object with edges selected (bottom)
Selected edges removed from original object (top) and unwanted edges removed (bottom)
Interface
Selection rollout
See Editable Poly for information on the Select rollout settings.
Soft Selection rollout
Soft Selection controls affect the action of sub-object Move, Rotate, and Scale functions. When these are on, gmax applies a spline curve deformation to unselected vertices surrounding the transformed selected sub-object. This provides a magnet-like effect with a sphere of influence around the transformation.
For more information, see Soft Selection Rollout.
Edit Geometry rollout
Create: Creates an edge from vertex to vertex. The edge you create separates the polygons. For example, by creating an edge inside a four-sided polygon, you turn the polygon into two triangles.
Delete: Deletes selected edges.
Attach: Lets you attach another object in the scene to the selected editable poly. You can attach any type of object, including splines and patch objects. Attaching a non-mesh object converts it to editable-poly format. Click the object you want to attach to the currently selected poly object.
For further details, see Attach.
Split: Divides the mesh along the selected edges. This does nothing when applied to a single edge in the middle of a mesh. The vertices at the end of affected edges must be separable in order for this option to work. For example, it would work on a single edge which intersects an existing border, since the border vertex can be split in two. Additionally, two adjacent edges could be split in the middle of a grid or sphere, since the shared vertex can be split.
Divide: Lets you divide edges into two edges with a new vertex where you click. Click Divide, and then select an edge to be divided. Each edge is divided where you click it. You can click as many edges as you want divided, in sequence. To stop dividing, click Divide again or right-click.
Collapse: Collapses selected edges by welding their vertices to a vertex at the selection center.
Chamfer: Click this button and then drag edges in the active object. The Chamfer spinner updates to indicate the chamfer amount as you drag.
If you drag one or more selected edges, all selected edges are chamfered identically. If you drag an unselected edge, any selected edges are first deselected.
An edge chamfer "chops off" the selected edges, creating new edges that move along the polygons on either side by <chamfer amount>. Some vertex chamfering is done at the ends to make this behavior work with the rest of the mesh. New chamfer polygons are created with the material ID of one of the neighboring polygons (picked at random) and a smoothing group which is an intersection of all neighboring smoothing groups.
Chamfer spinner: Adjust this spinner to apply a chamfer effect to selected edges.
Use Snaps with Cut for precision. Cut honors Midpoint, Endpoint, and Vertex snaps.
Slice Plane: Creates a gizmo for a slice plane that can be positioned and rotated where you want to slice the edges. Also enables the Slice button.
Reset Plane: When in Slice Plane mode, use this button to return to the previous plane.
Slice: Performs the slice operation at the location of the slice plane. The Slice button is available only when the Slice Plane button is highlighted. This tool slices the poly just like the Slice modifier in "Operate On: Face" mode.
Cut: Lets you divide a edge at any point, then divide a second edge at any point, creating a new edge or edges between the two points. Clicking the first edge sets the first vertex. A dotted line tracks the cursor movement until you click a second edge. A new vertex is created at each edge division. Alternately, double-clicking an edge simply divides that edge at the point clicked, with invisible edges on either side.
You can use Cut to cut across anywhere on or off the surface. Click one edge to start the cut, continue to pick edges to cut, and right-click to exit cut mode.
Use Snaps with Cut for precision. Cut honors Midpoint, Endpoint, and Vertex snaps.
Split: When on, the Slice and Cut operations create double sets of vertices at the points where the edges are divided. This lets you easily delete the new polygons to create holes, or animate the new polygons as separate elements.
Weld group
Selected: Welds selected edges that fall within the tolerance specified in the spinner.
Target: Allows you to select an edge to be welded to a second selected edge.
The pixels spinner to the right of the Target button sets the maximum distance in screen pixels between the mouse cursor and the target edge.
Create Shape: After selecting one or more edges, click this button to create a spline shape from the selected edges. A Create Shape dialog appears, letting you name the shape, set it to Smooth or Linear, and ignore hidden edges. The new shape's pivot is placed at the center of the poly object.
Make Planar: Forces all selected edges to become coplanar. The plane's normal is the average surface normal of all faces attached to the selected edges.
View Align: Aligns selected edges to the plane of the active viewport. In the case of orthographic viewports, this is the same effect as aligning to the construction grid when the home grid is active. When aligning to a Perspective viewport (including camera and light views), the edges are reoriented to be aligned to a plane that is parallel to the camera's viewing plane. (Perspective viewports have invisible camera planes.) In these cases, the selection of edges is not translated but only rotated.
Grid Align: Aligns the selected edges to the current construction plane. The current plane is specified by the active viewport in the case of the home grid. When using a grid object, the current plane is the active grid object.
Remove Isolated Vertices: Deletes all isolated edges in the object, regardless of the current selection.
Subdivide rollout
MeshSmooth group
These controls provide explicit MeshSmooth NURMS subdivision for object and sub-object smoothing using the MeshSmooth modifier.
Smoothness: Determines how sharp a corner must be before polygons are added to smooth it. Smoothness is calculated as the average angle of all edges connected to a vertex. A value of 0.0 prevents the creation of any polygons. A value of 1.0 adds polygons to all vertices even if they lie on a plane.
Separate By Smoothing Groups: Prevents the creation of new polygons at edges between polygons that don't share at least one smoothing group.
Separate By Materials: Prevents the creation of new polygons for edges between polygons that do not share Material IDs.
Tessellate group
Use these controls to tessellate (subdivide) selected polygons. Tessellation is useful for increasing local mesh density while modeling. You can subdivide any selection of polygons. Two tessellation methods are available:
Tessellate: Tessellates selected polygons based on the Edge, Face-Center, and Tension (spinner) controls.
Edge: Inserts vertices in the middle of each edge and draws lines connecting those vertices. The number of polygons created will equal the number of sides of the original polygon.
Face: Adds a vertex to the center of each polygon and draws connecting lines from that vertex to the original vertices. The number of polygons created will equal the number of sides of the original polygon.
Tension: (Active only when Tessellate by Edge is active.) This spinner, below the Tessellate button, lets you increase or decrease the Edge tension value. A negative value pulls vertices inward from their plane, resulting in a concave effect. A positive value pulls vertices outward from their plane, resulting in a rounding effect.
Surface Properties rollout
Weight: Sets the weight of selected edges. Increasing an edge weight tends to push the smoothed result away.
Crease: Specifies how much creasing is performed on the selected edge or edges. At low settings, the edge is relatively smooth. At higher settings, the crease becomes increasingly visible. At 1.0, the highest setting, the edge is not smoothed at all.