Function prepare_material_bind_groups 

pub fn prepare_material_bind_groups(
    allocators: ResMut<'_, MaterialBindGroupAllocators>,
    render_device: Res<'_, RenderDevice>,
    pipeline_cache: Res<'_, PipelineCache>,
    fallback_image: Res<'_, FallbackImage>,
    fallback_buffer: Res<'_, FallbackBuffer>,
    fallback_resources: Res<'_, FallbackBindlessResources>,
    shader_buffer_assets: Res<'_, RenderAssets<GpuShaderBuffer>>,
    changed_shader_buffers: Res<'_, RenderChangedShaderBuffers>,
)

Creates and/or recreates any bind groups that contain materials that were modified this frame.