#bevy_ecs_ldtk

1145 messages · Page 2 of 2 (latest)

slow slate
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no, the anchors are currently top-left (you can see them in the screenshot)

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the spikes in-game are offset down, so any other anchor just pushes them further off

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have tried a few

foggy helm
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Bevy sprites are default anchored in the center though, unless you changed that?

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Not sure if bevy_ecs_ldtk propagates that

slow slate
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hmm, yeah i mean, the ldtk entities are anchored top-left but the position bevy_ecs_ldtk spawns them in is like, 6 pixels from the bottom center

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changing the ldtk anchor to center just puts them further off

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actually no, it just doesn't have any effect

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they're the same amount offset

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so maybe bevy_ecs_ldtk is like... trying to correct the anchor somehow and getting it wrong

slow slate
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i figured it out - the ldtk level size somehow got stuck in a non-integer multiple of the tile size and this was messing up bevy_ecs_ldtk's height adjustment in ldtk_pixel_coords_to_translation_pivoted

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the pixel height of the level was 10 pixels off from being an even number of tiles

idle niche
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nice detective work, sounds devious to troubleshoot

slow slate
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libraries always seem like an inscrutable black box until the moment i start just looking for "the bevy system that spawns this thing" lol

regal quiver
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Hello guys, good morning. I would like to chunk render my map based on the camera position and GridCoord. Do you know if there is an easy way to do that?

lament forge
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how should i handle different variants of entities? should i have an enum or should i just have separate entities for each?

lament forge
lament forge
vagrant summit
# lament forge how should i handle different variants of entities? should i have an enum or sho...

What's your use case? I think it kinda depends on how different the variants are, and how much you want to segregate them in system code. Like, if you had them be different entities, that allows you to give them different components, which allows you to access one or the other in queries really easily. But if they're mostly going to have the same behavior, then that might not be worth the trouble, and an enum field would suffice.

floral coyote
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What is the best way to add observers to entities spawned from the level, I want to implement something similar to https://bevy.org/examples/picking/mesh-picking/ with the hover function adding a marker component to the entities once hovered and remove it once not hovered, I know I can add a system that checks for <add> entities but what is the best way to do it, is there a way to hook into the spawn process directly?

Mesh Picking

Bevy is a refreshingly simple data-driven game engine built in Rust. It is free and open-source forever!

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floral coyote
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Thanks in advance and love using this library for my game!

slow slate
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in particular you can add a world observer with Trigger<OnAdd, Player> instead of using the Added filter to hook into the process more directly

floral coyote
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So an observer that adds the other generic observers that will act onHover? @slow slate

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I used the blueprint method for initializing rigid bodies on walls so far and etc, just wanted to know if this is the best way to do so here as well

slow slate
vagrant summit
# floral coyote What is the best way to add observers to entities spawned from the level, I want...

looking into observers now, but the limitation for doing it w/ derive(LdtkEntity) would be that you don't have access to the bevy Entity associated w/ the ldtk entity, which you would want sometimes. But if it's okay if the use case allows for global observers

fn observe_hovers(_: &EntityInstance) -> Observer {
    Observer::new(|trigger: Trigger<Pointer<Over>>| {
        println!("detected hover");
    })
}

#[derive(Bundle, LdtkEntity)]
struct MyLdtkEntity {
    #[with(observe_hovers)]
    observer: Observer,
}

Haven't tried compiling this or anything, just an idea

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I imagine in most observer pattern use cases, post-processing/blueprint would be required

floral coyote
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Yeah that’s what i thought as well

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Thanks so much for the help!

still pendant
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using #[from_entity_instance] is there a way to pass in the world size?

lament forge
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is there a way to respawn the player when hot reloading?

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it's worldly

lament forge
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@vagrant summit

vagrant summit
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lament forge
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is that a thing in vanilla ldtk or specifically the bevy implementation?

vagrant summit
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it's not really a documented concept or anything, it's just whatever level the player is actually placed in in LDtk. When the world respawns it'll just despawn everything and then start the spawning process again for whatever levels are currently selected. If none of the currently selected levels contain the player in LDtk, then the player wouldn't be spawned.

Idk if that's what you're observing, just a guess

lament forge
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it works when the starting level is loaded in

vagrant summit
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that makes sense. Are you changing the level selection as the player traverses the world, like the platformer example?

lament forge
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yeah

vagrant summit
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You could potentially hack around this, though I can't guarantee how well it would work. Instead of making the player worldly, which makes it a child of the world and thus despawned on hot-reload, you could go further and make it not have a parent at all

slow slate
# lament forge it works when the starting level is loaded in

fwiw, the way i worked around this was to completely decouple the player spawn from level spawn - instead, i placed spawn points in the levels (invisible but always exist) and have the player spawn on the current level's spawn point (found by iterating children in the current level)

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player needing a respawn is marked by a resource being present

hoary gate
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hey @vagrant summit! quick question, how are you handling collisions and creating colliders? Is that deferred to devs to setup for walls/obstacles/etc, or do you parse any of the data in LDTk?

lament forge
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@vagrant summit any plans for 0.17? I can open a pr with basic stuff if you want but theres this new thing with tilemap chunks that I think is beyond my expertise

marsh stratus
lament forge
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ah cool, so migration should be pretty easy

marsh stratus
lament forge
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oh has that been done already? lol i was just doing it...

marsh stratus
vagrant summit
# hoary gate hey <@185087836511404032>! quick question, how are you handling collisions and c...

It's a bit different depending on whether you're spawning colliders for entities or trying to spawn large colliders that cover many intgrid tiles. But the plugin doesn't have anything built in for either, just hooks and tools for your own solution. The platformer example does a bit of both, there's a kinda complex function for spawning wall colliders that cover many intgrid tiles close-to-optimally

vagrant summit
lament forge
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@vagrant summit i opened a draft pr

lament forge
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looks like there's something wrong, every tile hitbox is spawning at the same place

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it might be an avian thing

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there are some other issues

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@vagrant summit I don't really know how to fix this, could you take a look?

vagrant summit
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yes I will, I appreciate you getting this started

vagrant summit
lament forge
lament forge
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@vagrant summit have you made any progress? It's possible it could be avian as well but I have no idea

vagrant summit
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I'll try and get some more examples working on your branch, if the necessary crates are available

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then maybe that'll reveal a bug

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Well there's definitely some strange stuff going on, but it looks like collision placement isn't completely broken

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Figured out one bug related to transforms. I'll push, hope you don't mind

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Ugh I messed up some git operation and lost the ability to contribute to your branch after rebasing it so your commits are gone from your remote. Terribly sorry

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Will put up a new branch on the upstream w/ your changes

foggy helm
lament forge
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Oh ok that's alright, ill see if it's working when I get home

vagrant summit
lament forge
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I think it's transform, ill see

lament forge
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@vagrant summit it's not fixed unfortunately

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it seems like a pretty normal usecase not sure why i'm having an issue

vagrant summit
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Made some changes to hopefully get CI passing

vagrant summit
lament forge
vagrant summit
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They are not, just rapier

lament forge
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ah, it's probably an issue with the avian integration then

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i'll send you the link to my project

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i think it would be easier than reproducing it? i can try if you want though

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oh wait i haven't pushed my migration yet one sec

vagrant summit
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nix flakes, nix config repo, based are we?

lament forge
random moth
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i was actually just trying to chase down this same issue and was trying to figure it out.
spawning entities with a Position component from avian fixes the issue, maybe scheduling issues related to the transform sync plugin?

more digging points to avian::physics_transform::transform::init_physics_transform overwriting the transform.

lament forge
random moth
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posted about it, someone pointed that it could be related to doing
spawn_empty().insert();

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i created a minimal example that showcases the issue.
https://github.com/Hellzbellz123/test_issue

CHANGING COMPONENT INSERTIONS DID FIX IT
leftover debug from my project was preventing me from seeing the changes.

moving the component insertions to the same fn call seems to fix the example but it doesnt work on my actual project

GitHub
GitHub - Hellzbellz123/test_issue

Contribute to Hellzbellz123/test_issue development by creating an account on GitHub.

random moth
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@vagrant summit @lament forge
i have fix but this seems like a hack
opened a pr on github.

im assuming inserting transform on entity instances at the end is an attempt to prevent them from being overwritten by whatever bundle you register so i left it.

lament forge
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@random moth i added your fork to my project and there are no colliders at all for some reason

random moth
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/cry

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how very strange

random moth
lament forge
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yeah that one

random moth
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doing some poking. ill get back with an @

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im dumb tho so no promises

random moth
# lament forge <@379121412582932480> i added your fork to my project and there are no colliders...

took me a while to get it to compile, did some poking, it seems that with my repo the colliders DO spawn, just all at 0,0. the change i made only effected the entity spawning codepath and not tile spawning.

i am unsure how to fix the intgrid spawning.
messed with internals a bit and spawning every tile with a transform causes the layers to get positioned strangely.

gross hack that 'fixes' the issue. im unsure on specific behavior for your game so youll have to test yourself.

fn toggle_avian_sync(
    time: Res<Time>,
    mut avian_cfg: ResMut<PhysicsTransformConfig>,
    mut level_transform_stuff: MessageReader<LevelEvent>,
    mut unpause_timer: Local<Timer>,
){
    let new_unpause_timer = Timer::new(Duration::from_secs_f32(0.1), TimerMode::Once);
    unpause_timer.tick(time.delta());
    for event in level_transform_stuff.read() {
        match event {
            LevelEvent::SpawnTriggered(_level_iid) => {
                // disable physics transform config
                avian_cfg.position_to_transform = false;
                *unpause_timer = new_unpause_timer.clone();
            },
            _ => {},
        }
    }
    if unpause_timer.is_finished() {
        avian_cfg.position_to_transform = true
    }
}
lament forge
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@vagrant summit @random moth my issue with colliders is now fixed on avian's main branch

vagrant summit
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thanks for all your efforts looking into this integration issue, @lament forge and @random moth , I feel more comfortable releasing 0.13 now

limpid briar
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When I load a level, it is not rendering the whole tilemap, even though the whole level is loaded (you can see from the colliders). Any idea what could be causing this? It doesn't happen with small levels I load. I am running the branch that works with bevy 0.17.

Screenshot_2025-10-30_at_1.44.13_PM.png
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limpid briar
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Here's another screenshot. The level I am currently in stops rendering, but I have load_level_neighbors on, so you can see some tiles render from the next level in the lower right. And colliders which are spawned from entities are still there. It seems to draw tiles from left to right, and stops drawing them after it gets to the 65th tile. It is happening on levels that are more than 64 tiles wide. The 65th tile and after is not drawn. It still happens if load_level_neighbors is off.

Screenshot_2025-10-31_at_10.32.25_AM.png
limpid briar
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It’s probably related to the new chunk rendering in bevy 0.17. Maybe a chunk is 64 tiles and it’s only rendering the first chunk of each level.

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Also I don’t know if the problem is the ldtk plugin or if it’s the underlying tilemap plugin

limpid briar
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I saw there were some new commits. I ran cargo update and the issue persists.

limpid briar
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Apparently this is happening because I am scaling the parent entity that contains the map. I don't want to use pixels as coordinates so I am scaling the parent that contains the tilemap. It is frustrating if there is no way to scale the map that works. I want to use tiles as units, not pixels.

It's because I am using physics I wanted to have my character be 2 units tall. But maybe I should just give up and use pixels.

foggy helm
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It doesn't look like it's using the new chunk rendering based on the commit history

limpid briar
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I don't know. In the features it says "Fast rendering using a chunked approach". Maybe it is a custom form of chunk-based rendering. But it seems I should have posted this in the thread for that plugin.

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I posted in the tilemap plugin thread also. Will see what they say. They will probably just say not to scale the map.

marsh stratus
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the issue here is allegedly related to scaling transforms, but we don't currently have a reproduction case to test.

vagrant summit
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0.13 is out

orchid needle
fleet pecan
vagrant summit
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Yeah I was just thinking yesterday it's probably within our purview to have at least some sort of tile grouping solution that can tell user where all rectangles of tiles are that to make it easier to spawn colliders

drifting pagoda
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is there a way to alter the z position of individual tiles in a layer? I know that you can offset their x and y positions but I haven't found a way to z-sort stuff properly other than dividing it in multiple layers which is kind of a pain.

drifting pagoda
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ok I found this, which kind of fixes my issue

vagrant summit
marsh stratus
drifting pagoda
# marsh stratus the render chunk size can reduce the chunk to a single tile, basically. only re...

this. The problem is that I also have walls that are 2-tiles high so I’d want to offset the z value of the upper tile so they have the same z, which isn’t possible afaik

I’m thinking of making a fork for it, although I’ll need to fork both crates which sucks

basically add an adjustable z to each tile, besides the existing x and y, and have chunks be offset by the z of one of the tiles they contain (top-right tile or whatever is convenient, a 1x1 chunk will just have the z offset of the single tile it contains)

should be relatively clean although a bit confusing for chunks that aren’t 1x1

vagrant summit
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shameless plug of my new crate: #crates message

minor zodiac
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Hello, not sure if I'm going against the grain here but, I created a level that has some terrain tiles and a single ldtk entity LoadNextLevel. The entity has a rectangle shape, an editor color, and a size of 32x32. However, when I load the ldtk file with the plugin, my terrain tiles show up, but the entity does not.

I'm guessing the entity doesn't render because it doesn't have any sprite info associated with it, but is there a way to have the entity spawn as a sprite with the rectangle shape and editor color I set? Maybe something I need to specify in the bundle struct?

I'm not sure if I should just specify a tile on the entity from the ldtk side, or add a system on the bevy side that looks for the LoadNextLevel entity and spawns its own bevy rectangle sprite from that. But in the bevy sprite case, I'd still like the sprite to use the color I had set in the editor field (see image). Does that color even get loaded on the bevy side?

Thanks and sorry for the wall of text. I'm new to using this plugin, but it seems great so far!

image.png
vagrant summit
# minor zodiac Hello, not sure if I'm going against the grain here but, I created a level that ...

With the plugin as it is today, I would expect the entity to still exist, but just not have any visuals. There isn't anything for showing entity color in the plugin today, we only do that for intgrid tiles that don't have a tileset.

So, you'll need to do something else if you want some visuals on it. Either by doing extra work on the bevy/plugin side to give it a visual, or doing some extra work on the asset side to give it a sprite. You could do the former by writing some Fn(&EntityInstance) -> Sprite entity that creates an orange rectangle sprite, then putting it on your bundle w/ the #[with] attribute macro: https://docs.rs/bevy_ecs_ldtk/latest/bevy_ecs_ldtk/app/trait.LdtkEntity.html#with

LdtkEntity in bevy_ecs_ldtk::app - Rust

Provides a constructor which can be used for spawning entities from an LDtk file.

minor zodiac
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Awesome, thanks for the info!

lament forge
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@vagrant summit is there any way to get the borders of the current room? i wanna improve my camera, it looks like you've planned to write doc for it but haven't done it yet?

vagrant summit
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Sorry I'm going to bed now, if you have more questions I won't see them

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waxen finch
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Sorry if this is a silly question, I've been trying to figure out how to do Entities that are animated/spritesheets. I had a look through the book and tried searching the docs-rs but couldn't really come up with anything.

I came across this video but Chris is doing it very manually here, is there a better way?

YouTube
chris biscardi
Drag and Drop player-built levels with Bevy and LDtk

drag-and-drop LDtk levels in a Bevy App

https://github.com/rust-adventure/yt-bevy-ldtk-drag-and-drop-levels

▶ Play video
regal quiver
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@waxen finch I think this is not the best place for this question since it is not related with ldtk or the crate itself...

However, answering it, I am doing the animation manually too. There is a Bevy example for it:

Sprite Animation https://share.google/UzN86axOMk53JpOsE

Sprite Animation

Bevy is a refreshingly simple data-driven game engine built in Rust. It is free and open-source forever!

waxen finch
# regal quiver <@116512483212132355> I think this is not the best place for this question since...

Right, do you put some metadata on the ldtk side and read that from in bevy (like number of sprites in the anim), or do you just recognise certain entities and hardcode the spritesheet configuration in bevy and use the ldtk entity as more of a "marker"?

I just assumed animated sprites would be a pretty common thing for a 2d game editor like ldtk. But I can see why ldtk wouldn't want to get into supporting it if it is trying to be purely a level editor.

tranquil folio
vagrant summit
# waxen finch Right, do you put some metadata on the ldtk side and read that from in bevy (lik...

Ultimately, LDtk and the plugin don't build-in a solution for animation, but it is pretty flexible for you to add some "application-defined" data. I am aware of users that are encoding animation indices for LDtk entities using entity fields. I think this is a good approach. The plugin has APIs for then accessing those fields if you have the EntityInstance (either by using a #[with(foo)] on the LdtkEntity-derived bundle, or by just querying for it).

See LdtkFields trait: https://docs.rs/bevy_ecs_ldtk/latest/bevy_ecs_ldtk/ldtk/ldtk_fields/trait.LdtkFields.html

LdtkFields in bevy_ecs_ldtk::ldtk::ldtk_fields - Rust

Convenience methods for accessing field instances.

lilac wigeon
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Hi everyone! Quick q regarding Worldly usage. Is this valid?

#[derive(Bundle, LdtkEntity)]
#[worldly]
struct MyBundle {
  // fields
}

Or should I do it like

#[derive(Bundle, LdtkEntity)]
struct MyBundle {
  // fields
  #[worldly]
  worldly: Worldly,
}

Thanks a lot! 😄

vagrant summit