Function bevy::render::batching::gpu_preprocessing::batch_and_prepare_sorted_render_phase

pub fn batch_and_prepare_sorted_render_phase<I, GFBD>(
    gpu_array_buffer: ResMut<'_, BatchedInstanceBuffers<<GFBD as GetBatchData>::BufferData, <GFBD as GetFullBatchData>::BufferInputData>>,
    indirect_parameters_buffer: ResMut<'_, IndirectParametersBuffer>,
    views: Query<'_, '_, (Entity, &mut SortedRenderPhase<I>, Has<GpuCulling>)>,
    system_param_item: StaticSystemParam<'_, '_, <GFBD as GetBatchData>::Param>
)
where
    I: CachedRenderPipelinePhaseItem + SortedPhaseItem,
    GFBD: GetFullBatchData,

Batch the items in a sorted render phase, when GPU instance buffer building is in use. This means comparing metadata needed to draw each phase item and trying to combine the draws into a batch.