Function queue_material_meshes 

pub fn queue_material_meshes(
    render_materials: Res<'_, ErasedRenderAssets<PreparedMaterial>>,
    render_mesh_instances: Res<'_, RenderMeshInstances>,
    render_material_instances: Res<'_, RenderMaterialInstances>,
    mesh_assets: Res<'_, RenderAssets<RenderMesh>>,
    mesh_allocator: Res<'_, MeshAllocator>,
    gpu_preprocessing_support: Res<'_, GpuPreprocessingSupport>,
    maybe_batched_instance_buffers: Option<Res<'_, BatchedInstanceBuffers<MeshUniform, MeshInputUniform>>>,
    opaque_render_phases: ResMut<'_, ViewBinnedRenderPhases<Opaque3d>>,
    alpha_mask_render_phases: ResMut<'_, ViewBinnedRenderPhases<AlphaMask3d>>,
    transmissive_render_phases: ResMut<'_, ViewSortedRenderPhases<Transmissive3d>>,
    transparent_render_phases: ResMut<'_, ViewSortedRenderPhases<Transparent3d>>,
    pending_mesh_material_queues: ResMut<'_, PendingMeshMaterialQueues>,
    views: Query<'_, '_, (&ExtractedView, &RenderVisibleEntities)>,
    specialized_material_pipeline_cache: ResMut<'_, SpecializedMaterialPipelineCache>,
    dirty_specializations: Res<'_, DirtySpecializations>,
)

For each view, iterates over all the meshes visible from that view and adds them to BinnedRenderPhases or SortedRenderPhases as appropriate.