Introduction

Builds the direction for the 3D network dataset according to the locations of the specified source and sink. The flow direction field is calculated according to the sink information field. Only the 3D network dataset that has created the direction can perform the facility network analysis.

Basic Steps

1. In the Environment Settings dialog box, click Create Flow Direction, click Build Direction for 3D Network to display Create Direction for 3D Network Dataset, as shown below:

Figure The Create Direction for 3D Network Dataset

2. In the Create Direction for 3D Network Dataset dialog box, select the 3D network dataset for flow creation, and set the Node ID Field, Edge ID Field, Start Node ID, and End Node ID for the network dataset.
3. In the Create Flow Direction section, set name for node type field and flow direction field. The default name for the generated node type field is NodeType, used to store the type of the imported nodes. The value 0 represents normal node, 1 represents source point and 2 represents sink point.
4. Click the Import button on the toolbar to the right to display the Import Node dialog box, in which you can set parameters for importing sources and sinks.
5. After importing successfully, you can directly click Node Type column to modify the node type of each node. Normal point, source and sink are supported. The default node type is source.
6. Click the node record in the node list to locate to corresponding node and the node will be highlighted in the scene.
7. The toolbar in the Create Direction for 3D Network Dataset dialog box provides commonly used functions for operations on sources and sinks, such as import and export sources and sinks, select all, select inverse, delete and uniform setting of node type.
Toolbar Introduction
• Import: Import source and sink data and perform parameter settings.

  Figure The Import Node dialog box

  Datasource: The datasource where the source and sink data to be imported is located.

  Dataset: The datasets for source and sink data.

  Node Type Field: If the type of source and sink points have already been saved in a field, you can select this field. While importing points, the node type information will be imported together.

  Filter: Import nodes that satisfy the filter condition. You can directly input the expression or click the Browse button to construct filter condition using SQL Expression. Please refer to SQL Expression Dialog Box.

  Associated Node Import: Check the box to import nodes using associated field. In some situation, we need to take network analysis stops as network nodes, we can select field in the point dataset as association field during import, then the field and the network node ID field will be associated to assist the import of nodes.

  Node ID Field: Consistent with the node ID field in the Environment Settings dialog box. The parameter can be used only if Associated Node Import is checked.

• Export: Export source and sink information and save it as dataset.

  Figure The Export Node dialog box

  Datasource: The datasource to save the exported points.

  Dataset: The name of the dataset to save the exported dataset.

  Node Type Field: The name of the node type field after import.

  Node ID Field: The name of the node ID field after import.

  Select selected records only: Check the box to export selected nodes in the list; otherwise, all nodes will be exported.

• Select All: Select all nodes in the list.
• Select Inverse: Select inverse nodes in the list.
• Delete: Delete selected nodes in the list.
• Uniform Settings: Assign node type for select nodes.
8. After parameter settings, click OK to create flow for 3D network dataset.

Note

1. While creating flow direction, river classification field and loop settings are not supported.
2. If the current network dataset has only one child network, network dataset flow direction can only be calculated by one source and one sink; if the current network dataset has multiple unconnected child networks, the network flow direction can be calculated by multiple sources and sinks.