Mesh Subdivide with Center Property Editor

Creates a new polygon mesh object by subdividing an existing one.

To apply: Select a polygon mesh object then choose Create Poly. Mesh Subdivision from the Model menu.

To redisplay: Select the generated subdivision surface, then choose Edit Properties Modeling Properties from the Edit panel and click the Mesh Subdivide with Center tab.

Inputs

Hide/Unhide	Hides all the inputs for the generated object to simplify the display of your scene in the 3D views, or unhides the inputs when you need to modify them.
Delete	Freezes the generator and deletes the inputs. This simplifies the scene once you are satisfied that you won't need to modify the inputs again.

Inputs' construction mode

Sets the connection point from which the operator reads to the top of the specified construction region of the input objects. For example, if this is set to Modeling, the operator reads the geometry and other attributes from the top of the inputs' Modeling region and ignores he effect of operators above it. If it is set to Secondary Shape (Result), it reads from the top of the inputs' entire stack, taking all operators into account.

Subdivision

Level

The number of times to subdivide the surface iteratively.

Each iteration increases the number of polygons, which can result in very dense and heavy geometry.

Rule

The mathematical method for calculating the subdivisions:

Catmull-Clark produces rounded shapes. The generated polygons are all quadrilateral. The higher the Subdivision Depth, the more this method approximates a bicubic standard B-spline surface. At regular vertices (exactly four edges), the surface has C2 (curvature) continuity; in other areas, the surface has C1 (tangential or parametric) continuity. The geometry produced is compatible with the method described in "Recursively generated B-spline surfaces on arbitrary topological surfaces" by E. Catmull and J. Clark (Computer-Aided Design 10(6):350-355, November 1978).
XSI-Doo-Sabin produces shapes with the same silhouettes as traditional Doo-Sabin but with different tessellation. One advantage over traditional Doo-Sabin is that XSI-Doo-Sabin correctly propagates clusters and cluster properties (including discontinuities) such as texture UVs, vertex colors, and weight maps. Another advantage is that XSI-Doo-Sabin handles creases and hard edges better.

Like traditional Doo-Sabin, XSI-Doo-Sabin produces shapes that follow the original mesh more closely than Catmull-Clark. If the original mesh has N polynodes, then each level L of subdivision has (4^L)N quad polygons. The higher the subdivision level, the more this method approximates a biquadratic uniform B-spline surface. At regular vertices, the surface has C1 (tangential or parametric) continuity; in other areas, the surface has G1 continuity (i.e., the tangents have the same direction but not necessarily the same length).
Linear subdivides the mesh without smoothing it. This is useful when you want an object to deform well but do not want to change its basic shape.
Doo-Sabin (obsolete) is provided for backward compatibility with scenes created with versions 3.5.1 and earlier. At each iteration, every polygon generates one similar polygon, every edge generates a new quadrilateral polygon, and every vertex generates a polygon with the same number of edges as were connected to the vertex. Unlike XSI-Doo-Sabin, this method does not correctly propagate clusters and cluster properties, and it does not handle creases very well. It is strongly recommended to use XSI-Doo-Sabin instead.

Use Loop Subdivision for Triangles

Subdivides triangles into smaller triangles, giving better results than quad-based methods. The Loop method avoids bulges and other artifacts when subdividing triangles. Catmull-Clark or linear is still used for non-triangles, and there is a smooth transition at boundaries between Catmull-Clark and Loop. Not available with XSI-Doo-Sabin.

Transfer Properties

Materials, UVs, VertexColors, WeightMaps	Transfers clusters and cluster properties from the input object to the generated object. All cluster properties of the following types are transferred: materials, texture UVs, color at vertices maps, and property weight maps (but not envelope weights).
Shape Animation, Envelope Weights	Transfers envelope weights and shapes. Shape clips and weights are duplicated.
Edit Transfer	Allows you to manually transfer and remove clusters and cluster properties. See Transferring Attributes Manually [Modeling and Deformation Basics].