Subdividing Meshes

Subdividing adds resolution to a mesh by increasing the number of its cells, which can useful when you need to add detail in a global manner or to create smoother surfaces.

The example below shows the results of subdividing a mesh.

Original mesh on left and subdivided mesh on right

The options for subdividing meshes are available in the Mesh Subdivider panel. Right-click the required mesh in the Data Properties and Settings and then choose Mesh Subdivider in the pop-up menu to open the Mesh Subdivider panel, shown below.

Mesh Subdivider panel

Mesh Subdivider panel

Parameters available for subdividing meshes
  Description
Mesh Indicates the currently selected mesh, to which the subdivision will be applied. If required, you can select another mesh in the drop-down menu.
Method Three filtering methods are available in Dragonfly to subdivide input polydata — Linear Subdivision, Loop Subdivision, and Butterfly Subdivision.

Linear subdivision… Each subdivision iteration creates 4 new triangles for each triangle in the mesh (see https://www.vtk.org/doc/nightly/html/classvtkLinearSubdivisionFilter.html#details).

Loop subdivision… Is an approximating subdivision scheme that creates four new triangles for each triangle in the mesh (see https://www.vtk.org/doc/nightly/html/classvtkLoopSubdivisionFilter.html#details).

Additional references can be found at:
[1] Loop, C., "Smooth Subdivision surfaces based on triangles," Masters Thesis, University of Utah, August 1987.
[2] Hoppe, H., et. al, "Piecewise Smooth Surface Reconstruction," ACM SIGGRAPH 1994 Proceedings, 295-302.

Butterfly subdivision… Is an interpolating subdivision scheme that creates four new triangles for each triangle in the mesh by implementing the 8-point butterfly (see https://www.vtk.org/doc/nightly/html/classvtkButterflySubdivisionFilter.html#details).

Additional references can be found at:
[1] Zorin, D., Schroder, P., and Sweldens, W., "Interpolating Subdivisions for Meshes with Arbitrary Topology," Computer Graphics Proceedings, Annual Conference Series, 1996, ACM SIGGRAPH, pp.189-192.

Note Refer to https://cmake.org/Wiki/VTK/Examples/CSharp/Meshes/Subdivision for more information about mesh subdivision.
Number of subdivisions Lets you set the number of subdivisions required.

You should note that for each subdivision level increase, the number of triangles will increase by approximately a factor of 4. For example, if n=2, the number of triangles in the resulting mesh will be 16x the number of triangles in the original mesh.
Create new mesh Lets you choose an output target — at the input so that the original mesh is transformed, or at the output so that a new mesh is created and the original remains unmodified.

Whenever possible, you should try to retain the original mesh so that you can compare the original and subdivided versions.
  1. Right-click the mesh that you want to subdivide in the Data Properties and Settings panel and then choose Mesh Subdivider in the pop-up menu.

    The Mesh Subdivider panel appears on the right side of the workspace.

  2. Select a subdivision method — Linear Subdivision, Loop Subdivision, or Butterfly Subdivision filtering.
  3. Select the number of subdivisions required.
  4. Check the Create new mesh option, if required.

    Whenever possible, you should try to retain the original mesh so that you can compare the original and subdivided versions.

  5. Click the Apply button.