Graph networks

CityEngine includes a suite of intuitive tools that allow you to create and edit graph networks. You can do the following with these tools:

• Create graph networks with street creation tools.
• Use the selection tool to select street nodes and edges. The selection displays in the Inspector, in which you can edit the attributes.
• Modify graph segments and nodes using the transform tools.
• See Segment and sidewalk parameters for more information.

Draw a polygonal street

To draw a polygonal street, click the Polygonal Street Creation tool (G) or click Graph > Polygonal Street Creation in the main menu.

Click to create the first vertex and click again to place additional vertices. To finish the street, double-click or press Enter. The streets automatically snap to shape vertices and edges. Additionally, you can snap to guides and align segments parallel and perpendicular to them. Press Shift to temporarily disable snapping. Double-click a street segment to add a vertex at that place.

Polygonal Street Creation tool options

The Polygonal Street Creation tool options window includes the following options:

Polygonal Street Creation
Segment Length (m)	The length of the current street segment in meters. Enter a value before or while drawing to lock the length. Press Enter to apply the value. Lock and unlock the length by clicking either the lock or the unlock button .
Re-use settings from neighbors	If enabled, settings are copied from neighbor streets, if available. If an existing street is extended, settings are typically copied from that segment.
Street width	The street width.
Left sidewalk width	The left sidewalk width.
Right sidewalk width	The right sidewalk width.
Rule file	The rule file is assigned to all new street shapes.
Apply rule-based model generation	If enabled, model generation is automatically triggered.
Align terrain	Aligns the street with the terrain.
Intersect Segments	Create a new node at the intersection of segments.

Draw a street freehand

To draw a street freehand, click the Polygonal Street Creation tool (S) and click the Freehand Street Creation tool (Shift+G) in the Tool Options window . You can also click Graph > Freehand Street Creation in the main menu.

Click and drag to start drawing a street and release when finished. The streets automatically snap to shape vertices and edges. Additionally, you can snap to guides and align segments parallel and perpendicular to them. Press Shift to temporarily disable snapping. Double-click a street segment to add a vertex at that place.

Freehand Street Creation tool options

The Freehand Street Creation tool options window includes the following options:

Freehand Street Creation
Re-use settings from neighbors	If enabled, settings are copied from neighbor streets, if available. If an existing street is extended, settings are typically copied from that segment.
Street width	The street width.
Left sidewalk width	The left sidewalk width.
Right sidewalk width	The right sidewalk width.
Rule file	If set, this rule file is assigned to all new street shapes.
Apply rule-based model generation	If enabled, model generation is automatically triggered.
Align terrain	Aligns the street with the terrain.
Intersect Segments	Create a new node at the intersection of segments.

Additional graph tools

CityEngine also includes additional tools to help with creating and editing streets, such as the Edit streets and curves, Cleanup streets, and Align streets to terrain tools.