Node parameters

Node parameters can be individually set for each graph node. The parameters for Node Shape are defined under Node Parameters in the Inspector.

Node Parameters

Note:

Parameters (attributes) can be mapped to Default, User, Object or to a map layer. See Mapping Attributes for details.

Node type parameter

Several parameters are available for the user to control the resulting node shapes. Node parameters define the type of the node and specifies geometry details like the radius of the arcs for instance.

Type (attr type)
Specifies the type of the node. Crossing, Junction, Roundabout or Freeway. Smart automatically chooses between these types.
Crossing
Junction
Roundabout
Freeway

General node parameters

The following tables describe the parameters that are common to all the node types:

Intersection Angle Minimum (attr angleThreshold)
Minimum angle between streets before they automatically start bending to avoid each other. It is ignored for freeways.
Crossing with Intersection Angle Minimum set to 30. Note the streets bending to avoid each other.
Crossing with Intersection Angle Minimum set to 10.

 

Precision (attr precision)
Specifies the level of detail. Value must be in the range [0, 1].
Crossing shapes with Precision = 0.1.
Crossing shapes with Precision = 0.3.

 

Create Shape (attr shapeCreation)

Enable/disable the shape geometry creation from the node.

Crossing and junction parameters

The Crossing, Smart, Freeway, and Junction parameters have the following parameters:

Curb Radius (attr minArcRadius)
The minimal arc radius. For freeways a higher value (>20) is better suited.
Given in absolute length units.
Crossing shapes with Curb Radius = 0.
Crossing shapes with Curb Radius = 5.

Block Corner (atrr cornerStyle)
Either Arcs or Straight. When set to the latter, blocks get simpler.
Border with Block Corner set to Arcs.
Border with Block Corner set to Straight.

Note:

The Block Corner parameter is not available when Type is set to Freeway

.

Roundabout parameters

When Type is set to Roundabout, the roundabout creation uses the following parameters:

Roundabout Island Radius (attr innerRadius)

Defines the radius of the inner circle (the "island shape").

 

Roundabout Street Width (attr streetWidth)
Defines the width of the roundabout street lane.
A roundabout with Roundabout Island Radius = 5 and Roundabout Street Width = 10.
A roundabout with Roundabout Island Radius = 10 and Roundabout Street Width = 5.

 

Curb Radius (attr minArcRadius)
The minimal arc radius. For freeways a higher value (>20) is better suited.
Given in absolute length units.
Crossing shapes with Curb Radius = 0.
Crossing shapes with Curb Radius = 5.

Principle street selection

The Junction and Freeway node types make use of the principle street to determine the node geometry. The principle street does not alter the Smart junction behavior.

Left: Two junctions with different principle streets. Right: Two freeway intersections with different principle streets. In each case the principle streets are drawn in a darker shade of grey.

Note:

The principle street is specified using either the street tool, or by setting the object attribute principleStreetStart or principleStreetEnd on adjacent streets as appropriate.

Examples

Simple curve
Valence-two nodes (nodes between 2 graph segments) usually lead to curves or links between the segments. Note: For valence-one (nodes at the end of a row of segments / cul-de-sac) or valence-two nodes it does not matter whether the type is Crossing or Junction.
Dead end street
By setting the type of a valence-one node to roundabout, one can model a cul-de-sac.
Junction
Junctions, as opposed to crossings, don't break a major street. Minor streets are connected to the major street by junction entries. Note: The two segments with the maximal street widths are automatically treated as major street.

Auto-generated connection attributes

Connection attributes provide basic information about the underlying graph and give context information. CGA rules may want to access the following attributes.

shapeType	Specifies the type of the node. Crossing, Junction, Roundabout or Freeway. Smart automatically chooses between these types, see Types.
valency	The number of street segments adjacent to a street node. Valency is added to all node shapes.

Note:

Connection attributes are object attributes of the graph node and are inherited to the shape, indicated by the italic font in the shape's Inspector.