How to solve several common problems in cityengine 3D modeling (1)

after cityengine was acquired by ESRI, it stepped into the GIS 3D modeling field. Because cityengine's unique rule-based modeling, this increases the efficiency of GIS 3D modeling. But if it is not a rule, we can solve all the problems. Sometimes we still need to do some processing in order to use the Rules smoothly to achieve better modeling results. Below are several common examples:
problem 1: many intersections turn right because they have more lanes, so how can we deal with this problem efficiently?
solution: Use ArcGIS to interrupt the road center line near the intersection and assign a wider attribute, in this way, cityengine will automatically read the new attribute and widen the path here. If the cross length requirement is not very accurate, batch processing can be performed. For example, the intersection (point) can be obtained in batch through intersection calculation of the road center line, and an appropriate buffer (surface) can be given to these points ), this buffer plane is used to cut the original road center line and obtain the road center line segments near the intersections to be widened. After that, these line segments are widened by modifying the width attribute in batches through field calculator. Then use the road rule in cityengine.
(before widening) (after widening)

Question 2:When a small angle of a road is at the intersection, the sidewalk is disordered.
Solution:This is a bug in cityengine 2011. Before this bug is solved, the solution is to manually encrypt the node at the intersection of small angles on the road and form an arc with a slightly larger radius.


(Small Angle disorder)
(Temporary response results)

Question 3:There is no branch road on the left, and after a line is introduced to the right, the green belt in the main road center is also disconnected. Although the two overlapping paths are in the same plane but do not run through, the isolation band in the middle is retained. This requirement often occurs when a vehicle is introduced or pulled out of the main road on one or both sides of the main road.
Solution:Write one-way routing rule and green belt rule in cityengine, divide the two-way routing rule into two one-way routing and green belt rule.



(Common two-way road rules and green belts are damaged due to intersection)
(Decomposed into one-way roads and green belts)

Issue 4: a main road is separated into two single lines due to terrain or mountain blocks.
solution: same as problem 3 solution.