Function Description
The capture function ensures that our editing work is more accurate, less prone to errors, and more convenient and easy to locate objects. The Capture module details how to turn on layer capture, how to use capture, and the types of capture that SuperMap supports.
Operating instructions
- Right-click the Vector Layer node in Layer Manager, and click to select the Capturable command in the pop-up Context Menu.
- When clicked, Capturable is activated to make the layer capturable, that is, the object in the layer can be captured by the mouse; otherwise, it cannot be captured.
- On the Layer Properties interface, select the Capturable check box so that objects in the layer can be captured by the mouse.
- The Capture icon in front of the Vector Layer node in
- Layer Manager is also used to control whether the Vector Layer can be captured. You can click this button to control whether the Vector Layer can be captured. Only when a
- layer is in a capturable and editable state, the mouse can capture the objects in the layer when selecting, editing, etc. In the layer.
Turn on layer snapping
The Capturable command is used to control whether the Vector Layer can be captured, that is, whether the mouse can capture the objects in the Vector Layer when selecting, editing, etc. In the Vector Layer.
Use snap
Users often need to locate specific positions when editing and drawing, but these positions are usually not easy to locate accurately by hand when drawing. Based on this demand, SuperMap provides a powerful image capture function, which is intelligently captured and positioned by the system. In practice, we are free to choose the type of capture. When snapping is enabled, the currently drawn nodes automatically snap to edges, other nodes, or other geometric features within tolerance.
Users can dynamically set snap items in the toolbar and menu bar during editing operations. The Snap Settings dialog also pops up by clicking the Snap Settings button in the Map Editing group on the Object Operation tab. You can set the type of capture and the capture parameters.
Snap type settings
Figure: Snap Type |
- The Type tab is used to control the turning on and off of the corresponding snap type. The list under the Type tab lists the 12 commonly used snap relationships. Refer to the Supported Capture Type for a description and illustration of the specific meaning of each capture function. When a capture type is checked, the corresponding capture function is enabled; when a type is not checked, the corresponding capture function is disabled.
- Priority: Set the priority of the snap types in the list. The order in which the snap types are listed in the list box determines the priority of the snap types. Snap types listed above have a higher priority than those listed below, as shown in the following figure. Select one or more capture types, and adjust the priority of the selected item through the Top, Bottom, Move Up and Move Down buttons on the right side of Priority.
Figure: Capture Item Priority - Enable: Select the Enable check box to enable all snap types; deselect the check box to disable all snap types.
- Default: Click the Default button in the dialog box to restore the default selected snap type.
Capture Parameter Settings
The Parameters tab is used to set the captured Parameters. Including setting contents such as snap tolerance, angle, length, number of snap objects, snap length, and whether to add nodes.
Figure: Snap Parameter |
- Capture tolerance The
capture tolerance can be set in the range of 1-20 in pixels, and the default value is 15. If you set a snap tolerance of more than 20, the system prompts the Greater than Maximum Value. That if the object to be snapped is within the set distance from the cursor, the object will be snapped. As shown in the schematic diagram of the cursor positioning area in the lower right corner of the dialog box, the size of the red circle (i.e., the cursor positioning area) varies with the setting of the capture tolerance.
- Fixed angle The
fixed angle can be set from 0 to 360 in degrees, and the default value is 90. If the fixed angle is not set in the Default range, the system will have Prompt. When drawing a line, if the angle between the line segment to be drawn and other line segments is equal to the set angle, the system will use the fixed angle capture icon to prompt.
- Fixed length The unit of
fixed length is the same as the map Unit, and the default value is 1000. If the length of the line segment to be drawn is equal to the set length, the system will give a prompt with the fixed length capture icon.
- Negligible line length The line length that
can be set to be ignored ranges from 1 to 120 in pixels, and the default value is 50. If you set the ignore line length range to be outside the Default range, the system will have Prompt. The value of the line length that can be ignored is the minimum length of the snap line. When the length of a line object is less than set value, it is not snapped.
- Add a node when point is snapped to the line If
checked, a node is inserted at the snap point of the line when the point is snapped to the line; if unchecked, a node is not inserted at the snap point when the point is snapped to the line.
- Default
Click this button to restore the Snap Settings parameters to the default parameters.
Snap Settings is a global setting, which takes effect for all Maps, and saves the Snap Settings before the last shutdown after restarting the program.
Supported Capture Type
The specific meaning of each capture type is described in detail below with illustrations and text.
Capture button | Capture description | Illustration |
Makes the currently drawn line perpendicular to other linear features, including extension lines. Illustration: The line segment being drawn is perpendicular to any existing line segment. |
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Makes the currently drawn line parallel to other linear features. Illustration: The line segment being drawn is parallel to any existing line segment. |
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Snap Line with Horizontal/Vertical。 Illustration: The line being drawn is horizontal. |
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Snap Segment in Fixed Length。 Illustration: The length of the line segment being drawn is a fixed value. |
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Snap Line a Fixed Angle to Previous Segment。 Illustration: The line segment being drawn forms a fixed angle with the previous line segment. The fixed angle value set here is 90 degrees. |
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Make the point you are currently drawing on an endpoint (the endpoint of a line or the endpoint of a polygon boundary line). Illustration: Snaps to the end of a line. |
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The current mouse point forms a horizontal or vertical line with points on other linear features. Illustration: The virtual line formed by connecting the mouse anchor point with the end point of any line segment is horizontal or vertical. |
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Snap Point on Line。 Illustration: The line is snapped, that is, the current mouse anchor point is on the snapped line. |
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Snap Point on Midpoint。 Illustration: Snaps to the midpoint of a line. |
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Snap Point on Point。 Illustration: Snap to the Middle Point of the line. |
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Make the currently drawn point on the On Extension Line of another linear feature. Illustration: Snap to the On Extension Line point of the line. |