Subdivide Modifier (Object Space)

The Subdivide modifier provides an algorithm for creating meshes used for radiosity processing. Processing radiosity requires meshes that have elements shaped as close as possible to equilateral triangles. The density of the mesh also needs to be considered in determining the resolution of the lighting details that need to be captured. The denser the mesh is, the finer the lighting detail and accuracy will be. The trade-off is a larger memory requirement and slower rendering times. The Subdivide modifier works on a whole object and does not work on selected faces in a mesh.

Select an object > Modify panel > Modifier List > Object-Space Modifiers > Subdivide
Standard menu: Make a selection. > Modifiers menu > Radiosity > Subdivide
Enhanced menu: Make a selection. > Modifiers menu > Subdivision Surfaces > Subdivide

Subdivide modifier breaks flat surfaces into meshes.

Although it is primarily developed for increasing the quality of radiosity solutions, the Subdivide modifier can also be used by any application that requires well-formed meshes. For example, irregular mesh elements generated for Terrain compound objects can be improved.

The modifier has world space and object space variants. In the world space modifier the size limit is on the mesh after it is transformed into world space coordinates. The object space modifier limits the size in object space coordinates.

Note: Typically, the Subdivide modifier is applied automatically to objects in the scene when a radiosity solution is processed. Meshing parameters can be set on a global basis in the radiosity control panel or for individual objects in the Object Properties dialog.

Tip: When you are satisfied with the subdivision settings on one object, you can drag the modifier to other objects to propagate it.

Interface

Size: Controls the size of triangles in the subdivided mesh. The length of the longest edge of any triangle will not exceed the square root of 2 times the size in the Subdivide modifier. The square root of 2 factor is used, so that a square whose edges are the size will not be subdivided.

Update group

The radio buttons in the Update group control when the meshing is done.

Automatic Updates immediately when changes are made to the controls or the mesh.
Render Updates only for rendering.
Manual Updates only when you click Update Now. Subdivision can be interrupted by pressing . If the subdivision is interrupted the Update mode is changed to Manual.

Update Now: Updates the mesh when Manual is turned on.

Display Subdivision: Controls whether all of the triangles are visible, or only the edges where face properties are changing. Allows you to reduce the visible triangles in the scene if it appears cluttered.