I need to calculate the shortest path between two selected lots in my working area. Unfortunately I haven't been able to find a built-in function for any path calculation.
Could you please suggest a suitable solution for my purpose. (Like a simple implementation of Dijkstra for city engine etc.)
You are right. CE does not have good built-in network analysis functions (unlike Network Analyst in ArcGIS).
As you know, CE is mainly used for building 3D city models from many sources, including GIS and DEM.
So, if you want to find out the shortest path between two points, advisable to use ArcGIS with Network Analyst or ArcGIS Online with Network Analyst.
You can implement network analysis totally within CityEngine using the built-in Python editor. Break out the CompSci 101 text book, or read here: