https://knowledge.autodesk.com/support/ ... e-faq.html
Why is Autodesk discontinuing new releases of Stingray?
Our customers are increasingly standardizing on two game engines, Unity and Unreal Engine for both games and VR/AR authoring. Both engines have built extensive content and resource ecosystems for developers to leverage. We feel we can better serve our customers by working more closely with Unity and Unreal Engine rather than trying to develop our own alternative.
To this end we recently announced a partnership with Unity Technologies to improve workflow between our products. We will continue to invest in building better, more interactive authoring tools for both games and design visualization but will be pursuing stronger partnerships with third party game engine developers rather than building our own engine.