The settings dialog window as well as all import plug-in settings can be accessed in the Edit / Preferences / Import/Export / IGES Import menu.
The Composition option determines the imported objects‘ grouping and sorting. Grouping can be done via Logical Structures, color (Order by Color) or defined IGES levels (Order by Level)
If Create Polygons Directly is active, imported files will be converted directly to polygon objects. If this option is not active, the imported files will be displayed as generator objects.
The orientation of Cinema 4D‘s X and Y axes are opposite to that of most CAD applications. Activating the Swap Y axis and Z axis will remedy this and correct the imported file accordingly.
Center All Object Axis will center each object. This option can be very helpful since IGES files often ignore local coordinate systems and use the global coordinate system instead.
Create Default Materials creates materials for colored objects.
Curve Subdivision Factor determines the settings for the subdivision of spline curves. In general, the value set will be multiplied by the number of control points (a different multiplication factor will be used for parametric curves without control points, such as arcs). Upon import, the result of this multiplication will be entered as the curve‘s subdivision rate in its object properties.
The Surface U/V Subdivision factor influences the spline‘s subdivision settings. For best results when trimming, the spline surface‘s subdivision should be at least twice that of the spline curve‘s subdivision.
Calculate Normals calculates additional normal tags for Cinema 4D which results in a more exact depiction of shadows and reflections.
Swap Normals reverses the direction of Normals.
If Filter Twice Assigned Trimming Curves is active, unnecessary trimming curves will not be imported.
If Helper objects were used, CATIA will save them as hidden objects. They will be ignored by the default settings. Activate Load Hidden Entities to import Helper objects as well.
If Debug Option is active, Tags will be generated upon import that contain detailed information on the IGES files.
The image above shows a Debug tag. It contains information about the corresponding IGES file.
For each entity of an unknown type, Load Unknown Entities will, when active, create a Null object in Cinema 4D. This gives a better overview of the structure of unknown files in the IGES format. The Debug option must be active.