Street and crossing shapes

Street and intersection shapes generated within the CityEngine consist of different shape types. Each shape type is defined by its start rule.

Default start rules for street shapes

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

Standard start rules

ColorShape start ruleCreated by
Street

Street

Street

Sidewalk

Sidewalk

Street, and all intersection types

Joint

Joint

Intersections with only 2 adjacent streets

Crossing

Crossing

Crossing or Smart intersections

Junction

Junction

Junction or Smart intersections

Freeway

Freeway

Freeway or Smart intersections

Freeway Entry

Freeway Entry

Freeway or Smart intersections

Roundabout

Roundabout

Roundabout or Smart intersections

Roundabout Island

Roundabout Island

Roundabout or Smart intersections

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 UVs.

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 execute the tool, select a set of shapes and then choose Graph > Reset Shape Attributes from the main menu.

Conflicts

Because the internal shape creation algorithm computes the intersection shapes for each node 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.

Conflict with street node
There is a conflict (red dashed line) because a street node is inside a crossing.
Street node conflict fixed
The conflict has been resolved by running the Graph Cleanup tool.

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