ExtractRenderNodeQueue shows up in the profiler between culling and rendering. Most of the time it takes .1 to .9 millisecond. However, if 25 (special) stones in my scene are enabled, it takes 20+ms and kills performance.
I have deleted everything out of my scene except light, camera, stones. There are 300 stones in the scene created from five different prefabs. Most of these stones cause no problems. However, there are 25 bad ones that, if enabled, cause this huge performance hit. There is nothing special about these stones. They are instances of the same prefab as the other stones. They use the same material. They are basic MeshFilter,MeshRenderer,Collider setup. The meshes range from 25 to 50 vertices. They are in a fairly ordinary location of the scene.
Does anyone have any idea what ExtractRenderNodeQueue does and why it might not like these stones?
Using Unity 5.4.1 on Windows building for Android.