If you hold the CTRL key (either alone or in combination with SHIFT and/or ALT) while you stroke, you display the Define Stroke dialog, where you assign the stroke.
You can see how the strokes are analyzed by examining the grid in the Stroke to Define area of the Define Stroke dialog. When you complete the drawing of a stroke, a nine-square grid is centered around the stroke and fit to its extents. The inner segments of the grid are assigned unique letters. Where the stroke crosses a segment, the letter associated with that segment is added to the stroke name. Thus, the direction and the shape of the stroke matter, but the size of the stroke has no effect.
The stroke is always centered within the grid. If you draw a stroke vertically from top to bottom, the stroke is named HK, because it crossed the segments labeled H and K, in that order. Had you drawn the stroke from bottom to top, it would have been named KH.
Tip: You can define more than one stroke for the same command. For example, you might assign a U shape stroke to Undo, but find that you sometimes draw only a J shape when attempting the U. By assigning both the U and the J strokes to Undo, you don’t have to worry about missing that stroke.
The following options are available in the Define Stroke dialog.
Displays the name of the stroke and shows the stroke you just drew as a series of white X’s connected by white lines. A green X represents the start of the stroke, and a red X represents the end. The labeled grid shows you how the stroke is recognized. Where the stroke crosses the labeled segments in the grid, a letter is added to the name of the stroke.
The window lists all commands to which you can assign a stroke. Select a command and click OK to assign the stroke displayed in the grid to the selected command. Depending on the type of command you choose in this list, various options become available in the Command Should Operate On area.
Currently assigned to stroke: Displays the name of the stroke currently assigned to the selected command. If the SHIFT or ALT keys were pressed when the stroke was drawn, they’re added to the name. For example: “Shift + HK” or “Alt + HK.”
Provides a number of options that specify which objects (if any) are affected by the command. These options are enabled or disabled depending on the type of command you’ve selected in the list window.
No Objects Just Execute the Command: This text is displayed when a command is chosen that is not specific to selected objects (such as Arc Rotate). When a command is selected that can be applied to selected objects, the following options become enabled:
Single Object at Start of Stroke: Causes the command to act on the object beneath the first stroke point in the active viewport.
All Objects in the Selection Set: Causes the command to act on all objects in the current selection set.
Choosing one of the options in this area lets you use the stroke itself to select multiple objects and then apply the command.
All Objects in Rectangle Extents: Selects all objects defined by the rectangular bounding of the stroke.
All Objects in Circular Extents: Selects all objects defined by the largest circle that fits within the rectangular bounding of the stroke.
Window/Crossing: When either of the above two options are chosen, these two options become available. Window selects only those objects entirely within the rectangular or circular region. Crossing selects all objects within or crossing the region.
Current Stroke Set: Displays the name of the current stroke set, and lets you review the strokes defined in that set. (You can create and save a number of different stroke sets. See Stroke Preferences.)
Review: Click to display the Review Strokes subdialog, where you can choose from a list of defined strokes and then see the stroke itself. You cannot edit strokes this way. To view, change, and delete strokes, draw the Review Strokes stroke (by default, a horizontal line from left to right).