# Objective
Volumetric fog was broken by #13746.
Looks like this particular shader just got missed. I don't see any other
instances of `unpack_offset_and_counts` in the codebase.
```
2024-12-06T03:18:42.297494Z ERROR bevy_render::render_resource::pipeline_cache: failed to process shader:
error: no definition in scope for identifier: 'bevy_pbr::clustered_forward::unpack_offset_and_counts'
┌─ crates/bevy_pbr/src/volumetric_fog/volumetric_fog.wgsl:312:29
│
312 │ let offset_and_counts = bevy_pbr::clustered_forward::unpack_offset_and_counts(cluster_index);
│ ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ unknown identifier
│
= no definition in scope for identifier: 'bevy_pbr::clustered_forward::unpack_offset_and_counts'
```
## Solution
Use `unpack_clusterable_object_index_ranges` to get the indices for
point/spot lights.
## Testing
`cargo run --example volumetric_fog`
`cargo run --example fog_volumes`
`cargo run --example scrolling_fog`
5b1f0b1ef5