To show you where the polygon mesh subdivision settings are in Softimage, I’m going to start in Arnold and work back into Softimage via SItoA.

So, let’s start with an Arnold polymesh shape, which has a number of subdivision parameters:

C:\solidangle\Arnold-4.1.3.3\bin>kick -info polymesh | find "subdiv"
ENUM          subdiv_type                       none
BYTE          subdiv_iterations                 1
FLOAT         subdiv_pixel_error                0
NODE          subdiv_dicing_camera              (null)
ENUM          subdiv_adaptive_metric            auto
ENUM          subdiv_uv_smoothing               pin_corners
BOOL          subdiv_smooth_derivs              false

In Softimage, you access most of these subdivison parameters by adding an Arnold Parameters property to a polygon mesh (you can’t add new parameters to Softimage built-in objects like a PolygonMesh, so we have to use a custom property).

• subdiv_iterations
• subdiv_pixel_error
• subdiv_adaptive_metric
• subdiv_smooth_derivs (Shape group)

Other Arnold subdiv parameters are mapped to existing Softimage parameters:

• subdiv_uv_smoothing is mapped to Smooth when subdividing in the
  Texture Projection Property Editor. If Smooth when subdividing is enabled, then subdiv_uv_smoothing is set to pin_corners; otherwise, it’s set to linear.
• subdiv_type is mapped to the Subdivision Rule list in the Polygon Mesh property editor. Linear goes to linear, and anything else (XSI-Doo-Sabin, Catmull-Clark) goes to catclark.

Finally, subdiv_dicing_camera is on the Subdivision tab of the global Render Settings.