Split polygon faces

The Interactive Split Tool and the Split Polygon Tool lets you split one or more polygon faces in a mesh by drawing a line across the faces to specify the location of the split.

When using either of these tools, the following conditions apply:

• A polygon is split only if the split line crosses two of its edges. (If the split line ends in the middle of a polygon, that polygon is not split.)
• Multiple polygons can be split by one split line. Any polygons the split line crosses are split.
  
  

To split a polygon face

1. Select Edit Mesh > Interactive Split Tool or Edit Mesh > Split Polygon Tool.
2. Click an edge where you want the split to begin.
3. To refine the split line you can:
   • Click additional points to define the direction of the split line.
   • Drag to move the previous point after you’ve placed it.
   • Constrain the placement of split line points (see below).
4. Click an edge to complete the split line, and either press or press y to perform the split. To finish the split and exit the tool, press . If you complete the split line by clicking on the interior area of a face, the split will end at the last edge crossed.
   Note

   Neither tool can cross and split the same edge twice in one operation. If you receive an error message “internal edge repeated” when splitting, press the Delete key to undo the previous step and then press Enter to complete the split. Then split across those faces in a second split operation.

To constrain the placement of split lines using the Interactive Split Tool

1. Select Edit Mesh > Interactive Split Tool >

   The Interactive Split Tool settings appear:

• Constrain to edges: Constrains any points you place to edges.
• Snap Magnets: Allows you to snap to points along the edge.
• Magnet Tolerance: Controls how close the vertex must be to a snapping point before the vertex snaps to it. Set this to 10 to constrain vertices to always be at snapping points.

To constrain the placement of split line points using the Split Polygon Tool

1. Select Edit Mesh > Split Polygon Tool > .

   The Interactive Split Tool settings appear:

• Split only from edges: Constrains any points you place to edges.
• Use snapping points along edge: Snaps points to regular distances along an edge.
• Number of points: Controls the number of magnet points inside edges.
  
• Snapping tolerance: Controls how close the point must be to a magnet before the point snaps to it. Set this value to 100 to constrain points so they are always at magnet points.

  To snap a point to the exact midpoint of an edge, turn on Use snapping points along edge, set Number of points to 1, and set Snapping tolerance to 100.

  Tip

  When you click an edge, the location of the vertex is displayed as a percentage distance on the Help Line. This is helpful when you want numerical confirmation of the split location. For example, 25% is a quarter of the distance, 50% is the halfway point.