Contour Selection1 Mar, 2003 By: Greg Jankowski
A feature within SolidWorks that allows for easier selection and more flexible use of sketches is the contour-selection function. This function allows for regions to be selected with a single click. The regions can be defined by single, multiple, open, or closed sketch boundaries.
In the example in Figure 1, there are two selected contours, with the third one highlighted for selection. The original sketch, shown underneath the feature, is a layout sketch with multiple closed boundaries. With the exception of the centerline, none of these sketch entities was broken or made a construction entity.
Figure 1. Sketching is easier with a tool such as SolidWorks contour selection that allows the selection of various regions simultaneously.
So why does contour selection make sketch easier and more flexible? Prior to the contour selection tool's existence, the example shown in Figure 1 would have been far more difficult and tedious to create; the sketch would have required the trimming of a number of sketch entities or changing them to construction types before they could be selected individually. The contour selection tool allows the designers the freedom to sketch as they wish and not worry about whether the sketch needs to be broken up or modified just to produce the feature.
Figure 2 shows an example of the sketch-contour selection that was used to define multiple profiles driven by a sketch pattern. There's an advantage to the sketch pattern in this case: because the cross pattern shown here was defined using an angle and a distance, it was easier to define the sketch and then use the contour selection to insert the frame and the inside-frame feature. The other notable item here is that Sketch1 (see icon in the upper-left corner of the image) drives both features. If this sketch changes, both features, frames and inside-frames, will automatically update. The contour-selection tool effectively reuses the geometry from Sketch1. Otherwise, to reuse sketch entities, the Convert Entities function would have to be used.
Figure 2. Contour selection allows the designer to reuse the same sketch for various internal elements.
Using Contour Selection
Contour selection can be used when creating a feature or a sketch. Here are the methods available:
- Creating a Feature. Open the Selected Contours field within the Property Manager and the contour selection tool is activated.
- Creating a Sketch. Press the right-mouse button and select Contour Select Tool. To get out of this type of selection, press the right-mouse button and select End Select Contours or select another sketch function (such as Line or Circle tools) and the selection mode will no longer be active.
|Table 1. Contour Types and Descriptions|
|Open||This is a non-contiguous (open) profile. An arc would be an example of a single, open contour.|
|Closed||This is a profile described by a contiguous (closed) boundary. A rectangle would be an example of single, closed contour.|
|Single||This is a single contour. A rectangle is an example of a single, closed contour.|
|Multiple||There is more than one contour. A rectangle with a circle in the center would be an example of a multiple, contained contour.|
|Contained||There are multiple contours enclosed within the largest contour. A rectangle with a circle in the center would be an example of a multiple, contained contour.|
|Disjoint||There is more than one contour that cannot be enclosed within a single profile. An example of a multiple, disjointed contour will be a pair of arcs placed side by side without touching each other.|
While contour selection is typically associated with a closed boundary, there are some types of features that can be created using an open profile. The ability to create multiple solid bodies allows for the combination of features that can be created based on whether the contour is open, closed, contained, or disjointed (see Table 1 for the descriptions of various contour types, and Table 2 for the different kinds of features obtainable from those contour types).
|Table 2. Contour Types and Features|
|Multiple Contained Closed||Base Extrude, Boss Revolve, Base Revolve|
|Multiple Disjoint Closed||Boss Extrude, Cut Extrude, Cut Revolve|
|Single Open or Closed||Surface Loft Section, Sweep Path or Guide, Surface Sweep Section, Cut Extrude Thin, Surface Revolve, Boss Revolve Thin, Base Revolve Thin, Surface Extrude, Boss Extrude Thin, Base Extrude Thin, Loft Guide, Cut Revolve Thin|
|Single Open||Cut Extrude|
|Single Closed||Loft Section|
There are visual clues to indicate the contour-selection mode that is active or the contour type that has been used to create a feature.
- Creating a Feature. The cursor changes to the contour icon, as shown in Figure 1.
- Creating a Sketch. The cursor and the confirmation corner, located in the upper right-hand corner of the graphics window, change to the contour icon.
- FeatureManager Design Tree. The sketch icon, shown under the feature, will display a contour icon for the sketch, as shown in Figure 2. When editing the definition of that feature, the selected boundaries are shown within the Selected Contours field.
The contour selection tool is a powerful feature that allows designers to create sketches that capture their design intent without the burden of sketching to accommodate the software. Designers are free to create the sketch as they see fit and use the contour selection tool to create the features.
About the Author: Greg Jankowski
Autodesk Technical Evangelist Lynn Allen guides you through a different AutoCAD feature in every edition of her popular "Circles and Lines" tutorial series. For even more AutoCAD how-to, check out Lynn's quick tips in the Cadalyst Video Gallery. Subscribe to Cadalyst's free Tips & Tools Weekly e-newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!