# Objective

- Fixes #9138

## Solution

- Calling `Camera2dBundle::default()` will now result in a
`Camera2dBundle` with `Vec3::ZERO` transform, `far` value of `1000.` and
`near` value of `-1000.`.
- This will enable the rendering of 2d entities in negative z space by
default.
- I did not modify `new_with_far` as moving the camera to `Vec3::ZERO`
in that function will cause entities in the positive z space to become
hidden without further changes. And the further changes cannot be
applied without it being a breaking change.

Done in order to match similar change in Bevy's camera (see
bevyengine/bevy#9310)

Done in order to match similar change in Bevy's camera (see
bevyengine/bevy#9310)

Adopted PR from dmlary, all credit to them!
#9915

Original description:

# Objective

The default value for `near` in `OrthographicProjection` should be
different for 2d & 3d.

For 2d using `near = -1000` allows bevy users to build up scenes using
background `z = 0`, and foreground elements `z > 0` similar to css.
However in 3d `near = -1000` results in objects behind the camera being
rendered. Using `near = 0` works for 3d, but forces 2d users to assign
`z <= 0` for rendered elements, putting the background at some arbitrary
negative value.

There is no common value for `near` that doesn't result in a footgun or
usability issue for either 2d or 3d, so they should have separate
values.

There was discussion about other options in the discord
[0](https://discord.com/channels/691052431525675048/1154114310042292325),
but splitting `default()` into `default_2d()` and `default_3d()` seemed
like the lowest cost approach.

Related/past work #9138,
#9214,
#9310,
#9537 (thanks to @Selene-Amanita
for the list)

## Solution

This commit splits `OrthographicProjection::default` into `default_2d`
and `default_3d`.

## Migration Guide

- In initialization of `OrthographicProjection`, change `..default()` to
`..OrthographicProjection::default_2d()` or
`..OrthographicProjection::default_3d()`

Example:
```diff
--- a/examples/3d/orthographic.rs
+++ b/examples/3d/orthographic.rs
@@ -20,7 +20,7 @@ fn setup(
         projection: OrthographicProjection {
             scale: 3.0,
             scaling_mode: ScalingMode::FixedVertical(2.0),
-            ..default()
+            ..OrthographicProjection::default_3d()
         }
         .into(),
         transform: Transform::from_xyz(5.0, 5.0, 5.0).looking_at(Vec3::ZERO, Vec3::Y),
```

---------

Co-authored-by: David M. Lary <dmlary@gmail.com>
Co-authored-by: Jan Hohenheim <jan@hohenheim.ch>