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  4. Digitizing Elements
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  4. Digitizing Elements
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  4. Digitizing Elements

Digitizing Elements

Digitizing (or drawing) elements on the Map View can be performed using the various model specific commands (e.g., Draw Storage Areas) or generic draw commands (e.g., Draw Polylines).

Digitizing Modes

The following digitizing modes commands are located at the bottom of the application:
  • Enable/ disable ortho mode (or press Function Key F8)
    Enabling ortho mode causes the software to restrict cursor movement to specific directions. It allows cursor movement only in the vertical and horizontal directions.
  • Enable/ disable snap mode (or press Function Key F3)
    Enabling the snap mode causes the software to snap the vertex of the drawn segment to a nearby existing vertex and/or an edge when the user releases the mouse button.

Digitizing Modes Image 1

Curvilinear Digitizing

When digitizing polylines, polygons, and other model elements, the user is provided an option to create curvilinear elements. This option provides a more naturally looking element. The software will fit a cubic spline through the digitized points, as shown below.
Digitizing Modes Image 1

Once the user has completed the digitizing of the curvilinear element, the software automatically inserts intermediate vertices to represent the curved element using short straight line polyline segments.

While digitizing using the curvilinear option, additional vertices need to be digitized to transition between straight line sections and curved sections. These additional vertices anchor the straight-line section and prevent it from becoming curved.

Linear and Orthogonal Modes in Curvilinear Digitizing

While drawing the curvilinear elements, the user can press and hold the [Shift] key to activate the orthogonal mode and the [Ctrl] key to switch to linear digitizing. This provides more control over the placement of the polylines where additional detail is needed.
Linear and Orthogonal Modes in Curvilinear Digitizing Image 3

Note that the tooltips for drawing the linear, curvilinear, and orthogonal segments are displayed on the status bar.

Linear Digitizing

The software, by default, allows the user to draw polygons and other model elements with linear elements. Linear elements are formative design elements used to represent linear features of model elements such as river stretches, roadway crossings, and bridge piers.

Curvilinear and Orthogonal Modes in Linear Digitizing

While drawing the linear elements, the user can press and hold the [Shift] key to activate the orthogonal mode and [Ctrl] key to switch to curvilinear digitizing.
Curvilinear and Orthogonal Modes in Linear Digitizing Image 4

Canceling the Digitizing Command

While the digitizing command is active, press the Esc key to cancel the command. The software will cancel the digitizing command.

Undo a Segment during Digitizing

While digitizing an element, press the CTRL+Z key (for Undo) to undo the last segment of the element being digitized. The CTRL+Z key can be pressed multiple times to undo multiple segments of the element while digitizing.

About the Author Chris Maeder

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