My CityEngine rules are really coming on now but I need time to think about how best to write the rules.   One thing I have started to learn is it’s really important to identify early on what attributes you want to control and which elements of the model you want to switch off.

You can use the case statement and an attribute with a true of false value to create that switch.   In practical terms it means you can fold many rule files into one, and at the flip of a switch reveal attributes that were previously hidden.

The example here shows my urban area (somewhere in a modern sub-division in the Middle East) in basic Google Earth style, but flip the on switch and the same model is now coloured according to a set of rules testing the lots area, red is too big, turquoise is near to the required lot size and green is within the lot area range I want.

Forget my choice of colour, this is a genuinely useful rule, being able to see what impact changes in the rule file are having is fantastic (but only if you’re a planner I suspect).

CityEngine’s power really comes when you see it as a design tool, it is by no means perfect but you can quickly set up a rule file and see the results of your ‘rules’ or planning standards very quickly.   What I hope is that ESRI allows ArcGIS to get some of CityEngine’s functionality, especially the dymanic street network capabilities of setting road and pavement widths…

I may put up a video showing just how quick this model refreshes itself… it’s interesting seeing how CityEngine runs the rule over you model colouring each model in turn…


  1. hi mr. i like learning the rules of cityengine . but i can not understand Where to start.can you Introduce a full Source about learning rules. very thanks


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