To symbolize a layer from CityEngine rules in Pro, you can use the Features from CityEngine Tool (Features From CityEngine Rules—Help | ArcGIS for Professionals )
1. In your scene, add the building footprints and drag them into the 3D layers group in the Table of Contents.
2. Go to the Analysis tab > Tools > and search for the Feature from CityEngine Tool and run the tool.
3. Once you run the output will be below the ground, so right click on the output layer > Elevation > and select Features are: On the ground.
