Meshing rules of SubD

SubDs in Rhino may be meshed in three different methods for rendering, viewport display, surface analysis, and mesh conversion. The three meshing methods are static, adaptive, and absolute.

Where in Rhino these meshing methods are used?

Static meshing

How many mesh quads are created per SubD quad is based on the face count of the SubD.

• Static meshing cannot be configured and previewed.
• SubDs in shaded viewports (Shaded, Rendered, Ghosted, and Xray display modes) use static meshing.
• Static meshing reduces the render mesh faces of dense SubDs to increase display performance.

Adaptive meshing

How many mesh quads are created per SubD quad is based on the face count of the SubD and the Adaptive subdivision level slider in meshing dialog boxes. The table below shows how many mesh quads will be created from each SubD quad. For example, when a SubD has 501-2000 faces, and the level slider is at 3, 8x8 mesh quads will be created from each SubD quad.

• SubD in the Raytraced viewport and final rendering use adaptive meshing set in Document Properties > Mesh or Object properties > Custom mesh.
• Adaptive meshing reduces the faces of render meshes on dense SubDs.
• Surface analysis commands use adaptive meshing.

Absolute meshing

How many mesh quads are created per SubD quad is completely based on the Absolute subdivision level slider. No other factor is involved.

• The detailed controls in the Mesh command and mesh file format export options is the only place in Rhino where absolute meshing is used. All the rest in Rhino use either Static meshing or Adaptive meshing.
• A high absolute meshing level may create too many mesh faces from dense SubDs and cause the system to run out of memory.

Use of three meshing methods

This table shows where in Rhino the three meshing methods are used for SubD.