Just a quick tip this one, and it starts to help you when you make very large city/urban models.   When you are starting to add more detail to your rule file buildings like nice windows or doors (or in my case balconies and air conditioning units) it’s always best to create a simplified model at the same time.   That way you can create a mechanism to speed up CityEngine, remember the more detail it has to draw the more PC resources it needs.

ce_tip_detail_simple_balcony
Guess what 3D modeller I use…

Once you’ve done this you can use the following rule syntax to enable easy switching off and on of the detail without losing the feel of your model.   Remember your urban model maybe small now, but because you will inevitably reuse this rule file and asset, it’s best to ‘front load’ some of the work.

attr toggledetail = false

asset_balcony =
case toggledetail == true : "assets/detailedBuildings/BuildingFeatures/balcony.obj"
else : "assets/detailedBuildings/BuildingFeatures/balcony_simple.obj"