Using AutoCAD Map 3D,
you can create node, network, or polygon topologies.
- Define the interrelation of nodes (point
- Are often used in conjunction with other
topologies in analysis.
- Connect links (lines) to form a linear
- Links can connect nodes.
An example of network
topology is a water-distribution application that traces the flow
of water from a pumping station to residences. A street network
is another example. For network topologies, you can specify the
direction for a link and specify the resistance for a link or node.
- Define polygons that represent enclosed
areas such as land parcels and census tracts. A single link defines
the common boundary between adjacent areas.
Uses of polygon topology
include tax assessment and land planning in which parcels of land
are represented by polygons. Political boundaries, such as voting
districts, city, state, or provincial boundaries, special districts,
and school districts, are other examples of the use of polygon topology.
When you create a topology,
keep the following points in mind:
- Before you create network or polygon
topologies, use the drawing cleanup tools to clean
up your map. Node topologies do not usually
- Before you create a topology, freeze
all layers containing objects in paper space (Layout tab). Otherwise,
these objects are included in the topology creation when you use
the Select All objects option.
- MAPTOPOCREATE can create topologies on
layers that are turned off. It does not affect layers that are frozen.
- When creating network or polygon topologies,
if you enable the Create New Nodes option, AutoCAD Map 3D detects
where lines are connected and assigns nodes to end points. It creates
physical or explicit node objects at all link end points where no
objects exist. If the layer you specify does not exist already, AutoCAD Map 3D creates
the layer with a color of 7 and a CONTINUOUS linetype.
- You can create nodes using ACAD_POINT.
To change their appearance and size, at the Command prompt, enter
- When you create a topology, information
is stored as object data on each element of the topology and is
saved with the map. Each node, link, or polygon is automatically
given a unique identification (ID) number. Each ID is automatically
processed when you use any topology command.
the BREAK command affects topology. If you use BREAK, you must use
MAPTOPOCREATE again to recreate the topology. You might also need to
clean up the geometry in the drawing again.