# Objective
- The prepass pipeline has a generic bound on the specialize function
but 95% of it doesn't need it
## Solution
- Move most of the fields to an internal struct and use a separate
specialize function for those fields
## Testing
- Ran the 3d_scene and it worked like before
---
## Migration Guide
If you were using a field of the `PrepassPipeline`, most of them have
now been move to `PrepassPipeline::internal`.
## Notes
Here's the cargo bloat size comparison (from this tool
https://github.com/bevyengine/bevy/discussions/14864):
```
before:
(
"<bevy_pbr::prepass::PrepassPipeline<M> as bevy_render::render_resource::pipeline_specializer::SpecializedMeshPipeline>::specialize",
25416,
0.05582993,
),
after:
(
"<bevy_pbr::prepass::PrepassPipeline<M> as bevy_render::render_resource::pipeline_specializer::SpecializedMeshPipeline>::specialize",
2496,
0.005490916,
),
(
"bevy_pbr::prepass::PrepassPipelineInternal::specialize",
11444,
0.025175499,
),
```
The size for the specialize function that is generic is now much
smaller, so users won't need to recompile it for every material.
af9fd4e939