Performing a Flood Trace
Concept Procedure Quick Reference
 
 
 
NoteThis procedure applies only to drawing objects.

To perform a flood trace

  1. Verify that you have a network topology available and it is loaded. See Creating Topologies and To load a topology.
  2. In Map Explorer, under Current Drawing, right-click a network topology Analysis Network Analysis.
  3. In the Network Topology Analysis - Select Method dialog box, click Flood Trace. Click Next.
  4. In the Network Topology Analysis - Choose Locations dialog box, click Start Point. Click Select Point to select the starting point in the map. Press Enter to return to the dialog box.

    AutoCAD Map 3D uses the node closest to the location you clicked as the start point. The coordinates of the point are shown in the list.

  5. Review the start point you have specified. The coordinates of the point are shown in the list.
    • To double-check the location of a point in the map, highlight the coordinates in the list. Click Preview.
    • To delete the point so that you can define a new one, highlight the coordinates in the list. Click Delete.
  6. Click Next.
  7. In the Network Topology Analysis - Direction and Resistance dialog box, select limits to put on the trace. For direction and resistance, you can enter a constant or an expression that references an object data field or linked external database column. The expression will be evaluated for each link. Click (Expression Evaluator) to select data from a list.
    • Link Direction — Specify a direction for the trace. If you leave the box blank, bi-directional (0) is used.
    • Reverse — Select this option to use the reverse of the direction indicated in the Link Direction box.
    • Link Direct Resistance — Specify the resistance to travel in the direction that a link was created. If you leave the box blank, the length of the line (.LENGTH) is used.
    • Link Reverse Resistance — Specify the resistance in the opposite direction along a link. If you leave the box blank, the length of the line (.LENGTH) is used.
    • Node Resistance — Specify the resistance to cross the node, for example, resistance for a valve in a pipe network, or a junction in a road network. If you leave the box blank, zero (0) is used.
    • Specify a maximum resistance for the trace. The analysis determines how many links and nodes can be traveled before the accumulated resistance exceeds the specified maximum resistance.

    For example, to trace out to a maximum length of 5000, set the Link Direct Resistance to .LENGTH and set the Maximum Resistance to 5000. To trace out to the first node on each link, set the Link Direct Resistance to 0, set the Node Resistance to 50 and set a Maximum Resistance of 45.

  8. Click Next.
  9. In the Network Topology Analysis - Output dialog box, indicate whether to view the results of the trace onscreen and whether save the flood trace results as a new topology.
    • To view your flood trace onscreen, select Highlight. Select the highlight color.
    • To save the flood path trace as a new topology, select Create Topology. Enter a name and description for the new topology. The new topology is created on the existing objects.
  10. Click Finish to perform the flood trace.