Why isn't all buildings shows as 3D models

[talcastro]

hello everyone. 
i need some help in cityengine please, for my university i need to get 3d model of the neighborhoods around heathrow airport but for some reason only a few buildings poop up as 3d while most stay as an image, 

please im looking for sometime now with no help i would love some guide or any other way to get the 3d model. 

thank you for the help.

[DevinLavigne]

Are rules applied to all of your shapes?