SolidWorks 2010 Bible

Part I: SolidWorks Basics

While sketching, symbols appear on the cursor to show that a relation will automatically be cre-

ated. These symbols have a yellow background and will apply horizontal, vertical, coincident, tan-

gent, parallel, and perpendicular relations. Figure 3.32 shows two situations where automatic

relations are applied — a horizontal and a tangent relation.

FIGURE 3.32

Some automatic relations that appear on the cursor

Inferencing in Sketch

Although SolidWorks users (even experienced ones) often confuse Inferencing and Automatic

Relations, these functions are not the same. Inferencing refers to the blue dotted lines that display in

Sketch mode when the cursor aligns with endpoints, centerpoints, or the Origin. Inferencing does

not create sketch relations, with one exception. If both ends of a line pick up the same inference to

the same point, SolidWorks will add that inference as an automatic relation.

When the cursor displays a small sketch relation symbol with a yellow background, this means

that an automatic relation is going to be applied. If the relation symbol has a white background,

the relation is inferenced, but not applied as an actual sketch relation. The symbols with the blue

(the color may also be green in SolidWorks 2008 or later) background are relations that have been

applied to existing sketch entities. The symbols look the same, regardless of background color. Be

aware that differences in versions and differences in color schemes can cause these colors to be dif-

ferent on your system.

Table 3.1 shows the symbols for the various inferences, automatic relation cursors, and applied

sketch relations. The difference between the three types is simply the background colors: white,

yellow, and blue, respectively.