Artifact in sprite rendering

[sofia-m-a]

Bevy version

0.15.0

[Optional] Relevant system information

`AdapterInfo { name: "AMD Radeon Graphics (RADV RENOIR)", vendor: 4098, device: 5686, device_type: IntegratedGpu, driver: "radv", driver_info: "Mesa 24.2.6", backend: Vulkan }`

What you did

Example code, using this CC0 tilemap texture Image

use bevy::prelude::*;
use std::collections::HashMap;

fn main() {
    App::new()
        .add_plugins(DefaultPlugins.set(ImagePlugin::default_nearest()))
        .add_systems(Startup, startup)
        .run();
}

fn startup(
    mut commands: Commands,
    assets: ResMut<AssetServer>,
    mut texture_atlas_layouts: ResMut<Assets<TextureAtlasLayout>>,
) {
    let texture_handle = assets.load_with_settings(
        "kenney_tiny-dungeon/Tilemap/tilemap_packed.png",
        |settings: &mut bevy::image::ImageLoaderSettings| {
            // Use `nearest` image sampling to preserve the pixel art style.
            settings.sampler = bevy::image::ImageSampler::nearest();
        },
    );
    let texture_atlas_layout =
        TextureAtlasLayout::from_grid(UVec2::new(16, 16), 12, 11, None, None);
    let texture_atlas_layout = texture_atlas_layouts.add(texture_atlas_layout);
    commands.spawn(Camera2d);

    let mut out = HashMap::new();

    { // generation, not super important, it just is easier to see the bug with some variety
        for x in -2..=2 {
            for y in -2..=2 {
                out.insert(IVec2::new(x, y), 48);
            }
        }

        for y in -2..=2 {
            out.insert(IVec2::new(-3, y), 13);
            out.insert(IVec2::new(3, y), 15);
        }

        for x in -2..=2 {
            out.insert(IVec2::new(x, -3), 26);
            out.insert(IVec2::new(x, 3), 2);
        }

        out.insert(IVec2::new(-3, -3), 25);
        out.insert(IVec2::new(3, -3), 27);
        out.insert(IVec2::new(-3, 3), 1);
        out.insert(IVec2::new(3, 3), 3);
    }

    for (place, kind) in out {
        let mut s = Sprite::from_atlas_image(texture_handle.clone(), TextureAtlas {
            layout: texture_atlas_layout.clone(),
            index: kind,
        });
        s.custom_size = Some(Vec2::new(1.0, 1.0));

        let scale = 6.0;
        commands.spawn((
            s,
            Transform::from_scale(Vec2::splat(16.0 * scale).extend(1.0))
                * Transform::from_translation(place.as_vec2().extend(0.0)),
        ));
    }
}

What went wrong

There is misalignment
It seems the bottom-left triangle of each quad has incorrect texturing, seemingly the wrong UVs, leading to it not matching the neighbouring triangle, and also bleeding over the edge of the atlas by 1 pixel

Additional information

Maybe its something to do with rounding?!

[sofia-m-a]

Additional note: those tiles that don't have a visible 1-pixel line underneath them happen to lie next to the tile below them on the tilemap
So they do have the same problem, it just happens to work out due to how the tilemap is arranged

[shanecelis]

Unfortunately I cannot replicate this on my machine with either v0.15.0 or the 'main' branch. I will try on my x86 machine later tonight.

AdapterInfo { name: "Apple M2", vendor: 0, device: 0, device_type: IntegratedGpu, driver: "", driver_info: "", backend: Metal }

[alexniver]

bleeding over the edge of the atlas by 1 pixel , I got the same issue in bevy 0.14

[Elabajaba]

The fix/workaround for this is to disable MSAA on your camera by inserting the Msaa::Off component on it.

[sofia-m-a]

@Elabajaba thanks, disabling MSAA does fix the borders on the bottom of the tiles. The triangular artifacts still remain