The AggregationProcessor reduces the amount of draw calls by taking a scene with multiple objects and materials and converting them to a single object with a single material. It will not produce any geometric changes. The original UV charts are preserved but repacked into a new unified texture atlas. There are some options regarding the UV creation.
It can also volumetrically cull triangles on insides of objects that are combined using the EnableGeometryCulling setting.
The Aggregation processor works with: