Street and intersection shapes

Shapes generated by nodes and segments have a different type (attribute shapeType) assigned. Each shape type is associated with a start rule.

Default start rules for street shapes

Standard start rules are Street, Sidewalk, Crossing, Junction, Freeway, FreewayEntry, Roundabout, RoundaboutIsland, and Joint.

Color	Shape start rule	Created by
	Street	Segment
	Sidewalk	Segment, and all node types
	Joint	Nodes with only two adjacent streets
	Crossing	Crossing node type
	Junction	Junction node type
	Freeway	Freeway node type
	Freeway Entry	Freeway node type
	Roundabout	Roundabout node type
	Roundabout Island	Roundabout node type

Note:

• Shapes have by default no rule file assigned. Therefore, if you like to work with these default start rules, you have to define the CGA rules Street, Sidewalk, Crossing, Junction, Freeway, FreewayEntry, Roundabout, RoundaboutIsland, and Joint. These rules will be the starting point for geometry generation.
• For information on the Block default start rules, see Block parameters.

Street shape UV values

For details of the UV coordinates, see Street and intersection shape UV.

Reset shape attributes

Since start rules can be overridden, users may want to use the Reset Shape Attributes tool to revert the start rules to the default values. To run the tool, select a set of shapes and choose Graph > Reset Shape Attributes in the main menu.

Reverse street direction

You can reverse the direction of your streets, including their sidewalks, in a CityEngine scene. Select a single or multiple street segments and click Graph > Reverse Direction in the main menu to change the direction.

Street before reverse direction tool

Street after reverse direction tool

Conflicts

Because the internal shape creation algorithm computes the node shapes individually, conflicts can occur. Usually, conflicts occur when the distance between two nodes is very small. In this case, at least one node is located inside the shape of a neighbor node.

Conflicting segments are marked with a red dashed line. The error color can be changed in the Viewport preferences.

There is a conflict (red dashed line) because a street node is inside a crossing.

The conflict has been resolved by running the Graph Cleanup tool.

To resolve conflicts, you can choose from the following actions:

• Clean up the graph; see Graph Cleanup tool
• Edit the graph network; see Street creation tools
• Change shape creation parameters (in other words, street width); see Segment and sidewalk parameters and Node parameters.
• Use the Edit graph network tool to edit curves, change street widths, or move nodes.