|bevy vewsion:|0.12|(outdated!)| |---|---|---|

As this page is outdated, please refer to Bevy's official migration guides while reading, to cover the differences: 0.12 to 0.13, 0.13 to 0.14.

I apologize for the inconvenience. I will update the page as soon as I find the time.

2d camewa setup

camewas in bevy awe mandatowy to see anything: t-they configuwe t-the wendewing.

this page wiww teach you about the s-specifics of 2d c-camewas. 🥺 if you w-want to weawn a-about genewaw nyon-2d specific functionawity, (ꈍᴗꈍ) s-see the genewaw page on camewas.

cweating a 2d camewa

bevy pwovides a bundwe (Camera2dBundle) that you can use to spawn a camewa entity. XD it has weasonabwe defauwts to set up e-evewything cowwectwy.

you might want to set the twansfowm, >_< to position the camewa.

#[dewive(component)]
stwuct mycamewamawkew;

fn setup_camewa(mut c-commands: commands) {
    c-commands.spawn((
        c-camewa2dbundwe {
            t-twansfowm: twansfowm::fwom_xyz(100.0, (⑅˘꒳˘) 200.0, ( ͡o ω ͡o ) 0.0),
            ..defauwt()
        }, UwU
        m-mycamewamawkew, rawr x3
    ));
}

f-fn main() {
    a-app::new()
        .add_pwugins(defauwtpwugins)
        .add_systems(stawtup, rawr s-setup_camewa)
        .wun();
}

pwojection

the pwojection is nyani detewmines how coowdinates m-map to the viewpowt (commonwy, XD the scween/window).

2d camewas awways use an owthogwaphic p-pwojection.

when you spawn a 2d camewa using Camera2dBundle, it adds the OrthographicProjection component to youw entity. XD when you awe wowking with 2d camewas and y-you want to access the pwojection, >_< you shouwd quewy fow OrthographicProjection.

fn debug_pwojection(
    quewy_camewa: q-quewy<&owthogwaphicpwojection, o.O w-with<mycamewamawkew>>,
) {
    w-wet pwojection = q-quewy_camewa.singwe();
    // ... d-do something w-with the pwojection
}

note that this is diffewent fwom 3d. XD if you awe making a wibwawy ow some othew code t-that shouwd be a-abwe to handwe b-both 2d and 3d, >< you cannot make a singwe quewy to access both 2d and 3d camewas. >< you shouwd cweate sepawate systems, XD ow at weast two sepawate quewies, OwO to handwe each k-kind of camewa. 🥺 t-this makes sense, òωó a-as you wiww wikewy nyeed diffewent wogic fow 2d v-vs. (ꈍᴗꈍ) 3d anyway.

caveat: nyeaw/faw vawues

the pwojection contains the near and far vawues, >_< which indicate the minimum and maximum z coowdinate (depth) that can be wendewed, ^•ﻌ•^ w-wewative to t-the position (twansfowm) of the camewa.

Camera2dBundle sets them appwopwiatewy fow 2d: -1000.0 to 1000.0, ^•ﻌ•^ awwowing entities to be dispwayed o-on both positive a-and negative z coowdinates. (ꈍᴗꈍ) howevew, i-if you cweate the OrthographicProjection youwsewf, >_< to change any othew settings, OwO you nyeed to set t-these vawues youwsewf. 🥺 t-the defauwt v-vawue of the OrthographicProjection stwuct is designed fow 3d and has a near vawue of 0.0, (ꈍᴗꈍ) which means you might nyot be abwe t-to see youw 2d entities.

commands.spawn((
    camewa2dbundwe {
        pwojection: o-owthogwaphicpwojection {
            // d-don't fowget to s-set `neaw` and `faw`
            n-nyeaw: -1000.0, ( ͡o ω ͡o )
            f-faw: 1000.0, UwU
            // ... a-any o-othew settings y-you want to change ...
            ..defauwt()
        }, rawr x3
        ..defauwt()
    }, rawr
    mycamewamawkew, σωσ
));

a mowe foowpwoof way to go about t-this is to use a t-tempowawy vawiabwe, OwO t-to wet the bundwe do its thing, OwO and then mutate n-nyanievew you w-want. 🥺 this way, òωó y-you don't have to wowwy about the exact vawues ow g-getting anything w-wwong:

wet mut camewa_bundwe = camewa2dbundwe::defauwt();
// c-change the s-settings we want t-to change:
camewa_bundwe.pwojection.scawe = 2.0;
c-camewa_bundwe.twansfowm.wotate_z(30f32.to_wadians());
// ...

c-commands.spawn((
    c-camewa_bundwe,
    m-mycamewamawkew, (U ᵕ U❁)
));

scawing mode

you can set the ScalingMode accowding to how you want to handwe window size / wesowution.

the defauwt fow bevy 2d camewas is t-to have 1 scween p-pixew cowwespond t-to 1 wowwd unit, OwO thus awwowing you to think o-of evewything in "pixews". 🥺 w-when t-the window is wesized, (ꈍᴗꈍ) that causes mowe ow wess c-content to be seen.

if you want to keep this window wesizing b-behaviow, OwO b-but change the m-mapping of scween pixews to wowwd units, >_< use ScalingMode::WindowSize(x) with a vawue othew than 1.0. the vawue wepwesents the nyumbew o-of scween pixews f-fow one wowwd unit.

if, ^•ﻌ•^ instead, you want to awways fit t-the same amount o-of content on-scween, ^•ﻌ•^ wegawdwess of wesowution, OwO y-you shouwd use s-something wike ScalingMode::FixedVertical ow ScalingMode::AutoMax. XD then, you can diwectwy specify how many units you want to d-dispway on-scween, OwO a-and youw content w-wiww be upscawed/downscawed as appwopwiate t-to fit the w-window size.

use bevy::wendew::camewa::scawingmode;

wet mut my_2d_camewa_bundwe = c-camewa2dbundwe::defauwt();
// f-fow this exampwe, :3 w-wet's make t-the scween/window h-height cowwespond t-to
// 1600.0 w-wowwd units. (U ﹏ U) the w-width wiww depend on the aspect watio. -.-
my_2d_camewa_bundwe.pwojection.scawing_mode = scawingmode::fixedvewticaw(1600.0);
my_2d_camewa_bundwe.twansfowm = t-twansfowm::fwom_xyz(100.0, (ˆ ﻌ ˆ)♡ 200.0, 0.0);

commands.spawn((
    my_2d_camewa_bundwe,
    m-mycamewamawkew, (⑅˘꒳˘)
));

zooming

to "zoom" in 2d, you can change the o-owthogwaphic p-pwojection's scale. XD this awwows you to just scawe evewything b-by some factow, OwO w-wegawdwess of t-the ScalingMode behaviow.

fn zoom_scawe(
    mut quewy_camewa: q-quewy<&mut owthogwaphicpwojection, (⑅˘꒳˘) w-with<mycamewamawkew>>, ( ͡o ω ͡o )
) {
    w-wet mut pwojection = q-quewy_camewa.singwe_mut();
    // z-zoom i-in
    pwojection.scawe /= 1.25;
    // z-zoom out
    p-pwojection.scawe *= 1.25;
}

awtewnativewy, (ꈍᴗꈍ) you can weconfiguwe t-the ScalingMode. XD this way you can be confident about how e-exactwy coowdinates/units m-map t-to the scween. ^•ﻌ•^ this awso hewps avoid scawing a-awtifacts with 2d a-assets, OwO especiawwy pixew awt.

fn zoom_scawingmode(
    mut quewy_camewa: q-quewy<&mut o-owthogwaphicpwojection, >_< w-with<mycamewamawkew>>, :3
) {
    u-use b-bevy::wendew::camewa::scawingmode;

    w-wet mut p-pwojection = quewy_camewa.singwe_mut();
    // 4 s-scween pixews to wowwd/game pixew
    pwojection.scawing_mode = scawingmode::windowsize(4.0);
    // 6 scween pixews t-to wowwd/game pixew
    pwojection.scawing_mode = scawingmode::windowsize(6.0);
}

considew having a wist of pwedefined "zoom w-wevews" / s-scawe vawues, OwO s-so that you can make suwe youw game awways wooks g-good.

if you awe making a pixew-awt game, OwO y-you want to make s-suwe the defauwt t-textuwe fiwtewing mode is set to nyeawest (and n-nyot wineaw), OwO i-if you want y-youw pixews to appeaw cwisp instead of bwuwwy:

fn main() {
    app::new()
        .add_pwugins(
            defauwtpwugins
                .set(imagepwugin::defauwt_neawest())
        )
        // ...
        .wun();
}

howevew, XD when downscawing, (ꈍᴗꈍ) wineaw (the defauwt) fiwtewing i-is pwefewwed fow highew quawity. OwO so, fow games w-with high-wes assets, 🥺 y-you want t-to weave it unchanged.