Generate a single buffer

Instructions for use

A simplex buffer is a polygon of a certain width that is automatically created around a point, line, or surface entity. The generated buffer results can continue to participate in subsequent analysis operations.

  • Currently, only point, line, and Region DatasetCreate Buffer Zone are supported, and CAD Dataset, Network Dataset, and Route DatasetCreate Buffer Zone are not supported.
  • Because of the different Data Types, the Parameter Settings in the Create Buffer Zone are completely different. For line data Create Buffer Zone, you can select either Round or Flat Buffer Type; for point/face data, only Round can be generated. When the Buffer Type is Flat, the Line Dataset can be used to generate buffers with different left and right radii or with only left or right buffers.
  • Region Dataset allows negative values when buffer distance is specified by Numeric. Point, Line Dataset can only have positive values. However, a buffer distance of 0 is not allowed for a point, line, or Region Dataset.
  • When the buffer distance is specified in the "field type" mode, if the specified field value of the object is null or 0, the Create Buffer Zone will not be made to the object; when the specified field is a negative value, the point and Line Dataset will be processed as a positive value; When generating Flat for line data, if the left (right) radius field of the line data is negative, the absolute value of the value is treated as the right (left) radius.

Function entrance

  • Select the Buffer item in the Spatial Analysis tab-> Vector Analysis-> Buffer-> drop-down menu;
  • Toolbox-> Vector Analysis Tool-> Buffer-> Buffer Item; (iDesktopX)

Parameter Description

  • Data Type: Select the type of data for which Create Buffer Zone is required.

    • You can point/Region Dataset or Line DatasetCreate Buffer Zone. Buffer Type needs to be set for Create Buffer Zone of alignment data, which can be Round or Flat, but not for Create Buffer Zone of point/surface data. Therefore, when creating a buffer zone for alignment data, there will be more options in the "Create Buffer Zone" dialog box. The parameters in the "Create Buffer Zone" dialog box are described below by taking the alignment data Create Buffer Zone as an example.

  • Buffer

    • Datasource: Select the Datasource where the Dataset to Create Buffer Zone is located.

    Dataset: Select the Dataset to Create Buffer Zone.

    The system automatically filters the Dataset under the selected Datasource according to the Data Type of Create Buffer Zone, and only displays the Line Dataset under the Datasource. If the Create Buffer Zone is for point/face data, only the points below the corresponding Datasource or the Region Dataset will be displayed.

    Only buffer for Selected Objects: The check box in front of "Only buffer for Selected Objects" is available when an object in a Dataset is selected. If this item is checked, it means that only the selected object can be used to Create Buffer Zone, and Datasource and Dataset cannot be set; Uncheck this item to perform the operation of Create Buffer Zone for All Objects under this Dataset, and you can change the Datasource and Dataset of Create Buffer Zone.

  • Set the Buffer Type. The parameters to be set are different for different Buffer Types.

    • Round: Draw parallel lines on both sides of the line according to the buffer distance, and draw a semicircle at the end of the line with the radius of the buffer distance to connect the Create Buffer Zone domain. The default Buffer Type is Round.

    When Flat: Create Buffer Zone, the line segment between the adjacent nodes of the line data is taken as a rectangular side, and the left radius or the right radius is taken as the other side of the rectangle to generate a buffer zone with a rectangular shape.

    When the line data is generated, buffers with different left and right buffer distances can be generated, or unilateral buffers can be generated.

    • Left Buffer: The left area of the alignment data Create Buffer Zone.
    • Right Buffer: Right area of the alignment data Create Buffer Zone.

    Only when "left buffer" and "right buffer" are checked at the same time, the buffer on both sides of the line data will be generated. The default is to generate both left and right buffers.

  • Set the buffer unit: the unit of the buffer distance, which can be millimeter, centimeter, decimeter, meter, kilometer, inch, foot, mile, degree, yard, etc.
  • Select how to specify the buffer distance.
    • Left Radius: Support direct input of left Buffer Radius:, or select a numerical field and use the field value as the left Buffer Radius:. You can also set an expression with the value of the expression as the left Buffer Radius:.
    • Right Radius: Support direct input of right Buffer Radius:, or select a numeric field and use the value of the field as the right Buffer Radius:. You can also set an expression with the value of the expression as the right Buffer Radius:.
  • Set the result options. It is required to set whether to merge after Create Buffer Zone, whether to Keep Attributes, whether to Add to Current Map Window, and the numerical value of semicircle line segment.

    • Union Buffer: Check this item to indicate that the buffer of multiple objects is merged. Uncheck this item to keep the generated buffer results and not perform the merge operation. As shown in the following figure, a multiple buffer is generated for two circles (blue). The generated buffer result is shown in Figure 1. Move the generated result and find that the two buffers are merged into a complex object. Figure 2 shows the merged buffer. Note: When Union Buffer is not checked, the buffers of different objects will not be merged into two separate simple objects.

    Figure 1: Single Buffer Results Figure 2: Merged buffer

    Keep Attributes: Check this item to indicate that each generated buffer will keep the corresponding non-system attribute Select Fields of the original object. Unchecking this will lose the Non-system Field: Attributes of the original object. This is checked by default. Note: This is not available when "Union Buffer" is checked.

    Show result in map: If this item is checked, it means that the generated results will be Add to Current Map Window after Create Buffer Zone. Uncheck this item, the result will not be automatically Add to Current Map Window. This is checked by default.

    Number of semicircular arc segments (4-200): Used to set the smoothness of the generated buffer boundary. The higher the number, the more the number of arc/arc segment equalizations, and the smoother the buffer boundary. The value range is 4-200. The default numeric size is 100.

  • Set Result Data.

    • Datasource: Select the Datasource to save the result of the generated buffer.

    Dataset: Enter the Dataset Name to save the generated buffer results. If the entered Dataset Name already exists, you will be prompted with Invalid dataset name and need to re-enter it.

Remark

Description of Buffer Radius: Buffer Radius: has two setting modes, numeric type and field type.

  • Numeric
    • Point and line data do not support negative radius, while surface data supports negative radius.
  • Field type
    • This method is valid only for buffering analysis of Dataset and recordset, and valid fields other than System Field: must be specified.
    • For Point and Line Dataset, when the Buffer Radius: field contains a negative value, its absolute value is taken as Create Buffer Zone.
    • Buffer Radius: When it is a field or field expression: for face data, if Union Buffer, its absolute value is taken, and if it is not combined, it is processed according to the negative radius.
    • Buffer Radius: When is a field expression: Valid only for buffer analysis of Dataset. That is, when the "Selected Objects Only" "option is checked, Buffer Radius is not supported: if the" Expression.. "" In the "Field Type" is set for analysis, the Analysis failed.
      • will be prompted

Related topics

About Buffer Zone Analysis

Create Multi-buffer