#### Understanding the Available Options

The Surface of Revolution check box is available if trimmed surfaces are being used that have a surface of revolution as a base surface and it is not being read in correctly. If this is the case, simply select the appropriate options in the Trimmed Surface area of the dialog box.

If the Default check box is selected, Planner will use the current setting to process all future entities.

The 'Process Entities with Use' Area

The Process Entities with Use area contains the following six check boxes that allow you to select the possible CAD image setup options. They are described in this table:

Check Box | Description
Geometry | Determines whether or not to import the geometric entities from the file. Geometric entities are the curves and surfaces that define the model.
Annotation | Determines whether or not to import the annotation entities from the file. These entities are used to add annotation or description to a file. These include angular dimension, diameter dimension, flag note, general label, linear dimension, ordinate dimension, point dimension, radius dimension, general symbol, and sectioned area entities.
Definition | Determines whether or not to import the definition entities from the file. These entities are used in definition structures of the file. These include general note, leader, associativity definition, line font definition, macro definition, subfigure definition, text font definition, text display template, and network subfigure definition entities.
Other | Determines whether or not to import the other entities from the file. These entities are used for other purposes such as defining features in the file. Currently, these include the color definition entity and the dimensioned geometry associatively.
Logical/Positional | Determines whether or not to import the logical/positional entities from the file. These entities are used as logical or positional reference by other entities. Currently, Planner does not process any entities that are of this type.
2D Parametric | Determines whether or not to import the 2-D parametric entities from the file. These entities are positioned in two-dimensional XY parameter space, and are considered a subset of three-dimensional XYZ space, by ignoring the Z coordinate. This entity type is intended for use in defining trimming curves on surfaces. Currently, Planner ignores this check box. For more information, see "The 'Trimmed Surfaces' Area".

If you select all six check boxes, then all IGES entities in the IGES file will be imported.

The 'Process Entities If' Area

The Process Entities If area contains check boxes that allow you to process certain entities when they meet certain conditions. The following table describes the available conditions that are met and the description of each check box:

Condition | Description
Process entities if Physically Dependent | Determines whether or not the base surface of a Curve on Parametric Surface will be shown.
Process entities if Logically Dependent | Determines whether or not logically dependent entities will be imported from the IGES file.
Process entities if Blanked | Determines whether or not blanked entities will be imported.

The 'Trimmed Surfaces' Area

The Trimmed Surfaces area contains check boxes that you may use to properly process Trimmed Surfaces.

Check Box | Description
Show Trim | Shows the trimmed surface.
Show Base Surface | Shows the untrimmed surface (base surface).
Use >‘B’ Curves | If >‘B’ curves are present in the IGES file, select this check box to use them as the trim definition. You may also need to select this check box if the model has poorly defined >‘C’ trimming curves. By selecting this check box, the >‘C’ trimming curves will be regenerated from the >‘B’ trimming curves.
Use >‘C’ Curves | If >‘C’ curves are present in the IGES file, select this check box to use them as the trim definition. You may need to use this option if the model has poorly defined >‘B’ trimming curves. By selecting this check box, the >‘B’ trimming curves will be regenerated from the >‘C’ trimming curves.

If you select the Show Trim check box, the other check boxes under it become available for selection. You can use either 'B' or 'C' curves as your trim definition, depending on the attributes of the trimmed surface.

Note: Be aware that if you use 'C' curves as your trim definition, Planner will have to calculate the 'B' curves that can be quite time consuming.

Also, if the IGES file contains trimmed surfaces that have a surface of revolution as a base surface these check boxes become available for selection:

Check Box | Description
Reverse Params | Determines whether or not to fix >‘B’ trimming curves that reverse the U and V parameters.
V Param 0 to 1 | Determines whether or not to fix the >‘V’ parameter that gets defined in the range 0 to 1, instead of in radians.
U Param 0 to 1 | Determines whether or not to fix the 'U' parameter that gets defined with a range of 0 to 1 instead of in radians when the generator of the surface of revolution is an arc.
Show Base Surface | Determines whether or not to show the untrimmed surface.

Defining Trimming Curves

You can define trimming curves in two ways:

- Using 3-dimensional coordinates in model space (the coordinates the surface is defined in). These are known as >‘C’ trimming curves because each coordinate requires three values to position it in model space (1, 2, 3; A, B, C). By definition, the curve must be defined so that it geometrically coincides with the surface. In other words, the curve must lie on the surface. However, a poorly defined ‘C’ trimming curve may break this rule.

- Defining the position of the curve using relative positions on the surface. These are known as >‘B’ trimming curves because each coordinate requires two values to position it in parametric space. For example, a rectangular surface could have the parametric position (0,0) at one corner and (1,1) at the opposite corner. Every position on the surface could then be represented using two-value pairs between these two extremes. The parametric position (0.5,0.5) would be in the center of the surface. The parametrically defined curve is represented using these 2-dimensional parameter-space points. By definition, the curve must be defined so that it does not go outside the parameter-space of the surface it lies on. However, a poorly defined surface may break this rule.

Example of Showing Trim

IGES File with Show Trim check box selected

Example of not Showing Trim

Using the IGES file in the "Example of Showing Trim" topic above, if you deselect the Show Trim check box, you will end up with an empty model. This is because this particular IGES file contains only trimmed surfaces. However, if you deselect the Show Trim check box and select the Show Base Surface check box, this is the result:

IGES File with Show Trim check box not selected

Notice that all the holes in the surfaces are gone and that the outer boundaries of the surfaces are not trimmed.