I am using 2015.2 CityEngine. My graphics card is Intel HD Graphics 4000. ESRI's requirement is NVIDIA: GeForce 6xxx / Quadro minimum NVIDIA graphics card or ATI: Radeon X1600 minimum ATI graphics card.
I am not able to see images or shapes in the viewport. I am thinking my graphics card is not compatible to CityEngine's requirement. Before I make a purchase, I need a confirmation to go with the purchase of a new and powerful desktop computer. #cityengine 2015
I can confirm, that CityEngine 2015.2 does not support Intel HD Graphics.
Before you make a new hardware purchase, you could try if the latest release of CityEngine 2016.1 works for you.
It now does officially support Intel HD 4400 and later.